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5,700 | Can sudden cardiac death be prevented? | Hypertrophic cardiomyopathy is regarded as the most common cause of sudden cardiac death in young people (including trained athletes). Introduction of implantable cardioverter-defibrillators to the hypertrophic cardiomyopathy patient population represents a new paradigm for clinical practice and perhaps the most significant advance in the management of this disease to date. Implantable defibrillators offer the only proven protection against sudden death by virtue of effectively terminating ventricular tachycardia/fibrillation and, in the process, altering the natural history of hypertrophic cardiomyopathy and providing the potential opportunity of normal or near-normal longevity for many patients. However, targeting the most appropriate candidates for prophylactic device therapy can be complex, compounded by the unpredictability of the underlying arrhythmogenic substrate, absence of a single dominant and quantitative risk marker in this heterogeneous disease, and the historical difficulty in assembling sufficiently powered prospective and randomized trials in large patient populations. Nevertheless, the current risk factor algorithm, when combined with a measure of individual physician judgment, is an effective strategy for identifying high-risk patients. Indeed, prevention of sudden death has now become an integral, albeit challenging, component of overall hypertrophic cardiomyopathy management. |
5,701 | Failure in short-term prediction of ventricular tachycardia and ventricular fibrillation from continuous electrocardiogram in intensive care unit patients. | Patients in the intensive care unit (ICU) setting are prone to malignant ventricular arrhythmias. We sought to test whether electrocardiographic (ECG) markers of autonomic tone, ventricular irritability, and repolarization lability could be used in short-term prediction of ventricular arrhythmias in this patient population.</AbstractText>We studied 38 patients with sustained (>30 seconds) monomorphic ventricular tachycardia, polymorphic ventricular tachycardia, or ventricular fibrillation while monitored in the ICU and 30 patients without arrhythmia in the ICU who served as controls. All patients had at least 12 hours of continuously recorded multilead ECG before arrhythmic event. Mean heart rate and measures of heart rate variability, QT variability, and ventricular ectopy were quantified in 1-hour epochs for the 12 hours before the arrhythmic event and in 5-minute epochs for the last hour preevent (and using a random termination time point in controls).</AbstractText>A modest downward trend in QT variability and a rise in heart rate were observed hours before polymorphic ventricular tachycardia and ventricular fibrillation events, although no significant changes heralded monomorphic ventricular tachycardia and no changes in any parameter predicted imminent ventricular arrhythmia of any type. There were no significant differences in ECG parameters between arrhythmia patients and controls.</AbstractText>In ICU patients, sustained ventricular arrhythmias are not preceded by change in ECG measures of autonomic tone, repolarization variability, and ventricular ectopy. Short-term arrhythmia prediction may be difficult or impossible in this patient population based on ECG measures alone.</AbstractText>Copyright 2010 Elsevier Inc. All rights reserved.</CopyrightInformation> |
5,702 | Exercise capacity is the most powerful predictor of 2-year mortality in patients with left ventricular systolic dysfunction. | There are few data about predictors of cardiovascular mortality and rehospitalization rate in patients with left ventricular systolic dysfunction (LVSD) after myocardial revascularization and optimization of pharmacological treatment.</AbstractText>1,346 consecutive patients with left ventricular ejection fraction (LVEF) < 45% (64 + or - 10 years, 73% male, LVEF 36.3% + or - 8%), who were referred for inpatient cardiac rehabilitation, were followed prospectively for 731 + or - 215 days in a unicentric prospective longitudinal registry. Multivariate logistic regression Cox models were used to analyze demographic, echocardiographic and exercise variables in order to determine independent predictors of cardiovascular mortality and rehospitalization.</AbstractText>LVEF failed to show prognostic power (hazard ratio [HR] 0.99 [95% confidence interval, CI, 0.94-1.03]; p = not significant), whereas moderate to severe mitral regurgitation (HR, 5.71 [95% CI 1.75-18.6]; p = 0.004) and atrial fibrillation (HR 1.67 [95% CI 1.15-2.44]; p = 0.008) were associated with a poorer prognosis. In an optimized multivariate model, 6-min walk test (HR 0.93 [95% CI 0.86-1.00] per 50 m; p = 0.049) and symptom-limited maximum exercise capacity test (HR 0.83 [95% CI 0.76-0.91] per 10 W; p < 0.001) as well as female gender (HR 0.58 [95% CI 0.39-0.84]; p = 0.005) were strong predictors for reduced overall mortality.</AbstractText>In patients with LVSD, independently of LVEF, traditional prognostic factors including atrial fibrillation or mitral regurgitation predict poorer survival, whereas symptom-limited exercise capacity and walking distance performed in 6-min walk test were highly predictive for a good prognosis.</AbstractText> |
5,703 | Development of malignant ventricular arrhythmias in a young male with WPW pattern. | In Wolff-Parkinson-White Syndrome (WPW), presence of accessory pathways causes various tachyarrhythmias that lead to different symptoms and clinical conditions in patients. Atrial fibrillation is observed in about 20-30% of this group of patients. Life threatening malignant ventricular arrhythmias and sudden cardiac deaths are observed in patients having rapid conduction in accessory pathways and short antegrade refractory periods (<250 msn). We present a WPW syndrome case that presented to the emergency service with narrow QRS tachycardia and later developed malignant ventricular arrhythmia. |
5,704 | Factors likely to affect the long-term results of ventricular stimulation after myocardial infarction. | The results of programmed ventricular stimulation (PVS) may change after myocardial infarction (MI). The objective was to study the factors that could predict the results of a second PVS.</AbstractText>Left ventricular ejection fraction (LVEF) and QRS duration were determined and PVS performed within 3 to 14 years of one another (mean 7.5+/-5) in 50 patients studied systematically between 1 and 3 months after acute MI.</AbstractText>QRS duration increased from 120+/-23 ms to 132+/-29 (p 0.04). LVEF did not decrease significantly (36+/-12 % vs 37+/-13 %). Ventricular tachycardia with cycle length (CL) > 220ms (VT) was induced in 11 patients at PVS 1, who had inducible VT with a CL > 220 ms (8) or < 220 ms (ventricular flutter, VFl) (3) at PVS 2. VFl or fibrillation (VF) was induced in 14 patients at PVS 1 and remained inducible in 5; 5 patients had inducible VT and 4 had a negative 2nd PVS. 2. 25 patients had initially negative PVS; 7 had secondarily inducible VT, 4 a VFl/VF, 14 a negative PVS. Changes of PVS were related to initially increasing QRS duration and secondarily changes in LVEF and revascularization but not to the number of extrastimuli required to induce VFl.</AbstractText>In patients without induced VT at first study, changes of PVS are possible during the life. Patients with initially long QRS duration and those who developed decreased LVEF are more at risk to have inducible monomorphic VT at 2nd study, than other patients.</AbstractText> |
5,705 | [Life-support training to improve the clinical competence of pharmacy students]. | Life-support (particularly, advanced life-support) training is not included in pharmacist education; however, the life-support should be mastered since a pharmacist is a medical professional. We consider it to be important to master other skills before the life-support practicing, because a pharmacist does not check a patient to assess their clinical condition and administer drugs (suppository, intravenous injection etc.) The pharmacist prepares medicines, but does not administer medicines to treat the patient. Furthermore, the pharmacist is not interested in the vital signs of the patient receiving the medicines (the pharmacist has not identified the patient has complaint from changes in vital signs), which is why pharmacists can not develop themselves as medical professionals. Based on this observation, life-support training should be considered. In other words, to foster pharmacists with high clinical competence, pharmacy students should receive life-support training after training in drug administration and vital sign checks in a bedside training room. Drug administration using a pharmacy system versatile-type training model and pharmacy training model, vital signs check and auscultation using a physical assessment model and a cardiac disease disorder simulator in our bedside practice are useful for advanced life-support using a high-performance care simulator (monitoring vital signs, adrenalin administration and oxygen inhalation for ventricular fibrillation (VF). These training skills can improve the clinical competence of pharmacy students. |
5,706 | A comprehensive investigation of cardiac arrest before and after arrival of emergency medical services. | Many of the factors that affect survival from out-of-hospital cardiac arrest are not relevant in patients who arrest after arrival of emergency medical services (EMS). Because all arrests that occur after arrival of EMS are witnessed and care is immediate, one might expect survival to be very high. Several studies have described communities' experiences of arrest after arrival but few have compared survival rates stratified by rhythm and witness status. The purpose of this paper was to describe the characteristics of patients who arrested after arrival of EMS and to compare survival in this population to those who had witnessed and unwitnessed arrests before EMS arrival.</AbstractText>We conducted a retrospective cohort study in King County, WA, USA. Descriptive statistics were calculated in patients whose arrests were not witnessed, in patients whose arrests were witnessed by citizens, and in those whose arrests were witnessed by EMS personnel.</AbstractText>The majority of bystander- and EMS-witnessed arrests were initially in ventricular fibrillation (VF), but EMS-witnessed arrests were more likely to initially have been in pulseless electrical activity (PEA) than bystander-witnessed events. Patients whose arrests were witnessed by EMS had the greatest likelihood of survival compared to patients whose arrests were not witnessed or were witnessed by bystanders. Patients whose arrests were witnessed by EMS and were initially in VF had the highest rates of survival (59%).</AbstractText>Patients whose arrests were witnessed by EMS were more likely to have survived their cardiac arrests than those who arrested before EMS arrived. We suggest that survival rates from VF arrests that occur after EMS arrival should be widely reported in order to measure overall EMS performance since many factors such as response times, bystander actions, and witness status are equalized in this subset of patients.</AbstractText>Copyright 2010 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
5,707 | Antidromic His capture during entrainment of orthodromic AVRT. | A narrow QRS tachycardia with eccentric atrial activation is presented with features favoring an orthodromic atrioventricular re-entrant tachycardia including an extranodal paraHisian response, and a short corrected post-pacing interval to tachycardia cycle length difference following right ventricular entrainment. However, during entrainment, the H-H interval was entrained by the pacing train several beats prior to the A-A interval which would suggest an atrioventricular nodal re-entry tachycardia. We discuss the diagnosis and its mechanism. |
5,708 | Intrathoracic impedance preceding ventricular tachyarrhythmia episodes. | Heart failure is associated with ventricular tachyarrhythmias (VT/VF). Fluid accumulation during worsened heart failure may trigger VT/VF. Increased intrathoracic impedance has been correlated with fluid accumulation during heart failure. Implanted defibrillators capable of daily measures of intrathoracic impedance allow correlation of impedance with occurrence of VT/VF. We hypothesized that VT/VF episodes are preceded by decreases in intrathoracic impedance. The goal was to identify the relationship of intrathoracic impedance measured by implanted cardioverter defibrillators to the occurrence of VT/VF.</AbstractText>Implanted defibrillator follow-up data were obtained retrospectively. Those with Medtronic OptiVol (Medtronic Inc., Minneapolis, MN, USA), storing averaged daily and reference impedance values, were reviewed for VT/VF episodes. Impedance changes in the week leading up to VT/VF were analyzed.</AbstractText>A total of 317 VT/VF episodes in a cohort of 121 patients' follow-up data were evaluated. Averaged daily intrathoracic impedance declined preceding 64% of VT/VF episodes, with an average decline of 0.46 +/- 0.35 Ohms from the day before the VT/VF episodes. However, the mean values of the averaged daily and reference impedance did not change significantly. A novel measure, DeltaTI, the sum of the daily differences between the averaged daily and reference impedance, was negative preceding 66% of VT/VF episodes (P < 0.001). The mean DeltaTI was -4.0 +/- 1.3 Ohms, which was significantly lower than the theoretically expected value of zero Ohms (P < 0.01).</AbstractText>(1) Averaged daily impedance declined preceding 64% of VT/VF episodes, but the overall decline was of small magnitude; (2) a novel measure, DeltaTI, was negative preceding 66% of VT/VF episodes, and significantly below zero.</AbstractText> |
5,709 | Effect of an electronic control device exposure on a methamphetamine-intoxicated animal model. | Because of the prevalence of methamphetamine abuse worldwide, it is not uncommon for subjects in law enforcement encounters to be methamphetamine-intoxicated. Methamphetamine has been present in arrest-related death cases in which an electronic control device (ECD) was used. The primary purpose of this study was to determine the cardiac effects of an ECD in a methamphetamine intoxication model.</AbstractText>Sixteen anesthetized Dorset sheep (26-78 kg) received 0.0 mg/kg (control animals, n = 4), 0.5 mg/kg (n = 4), 1.0 mg/kg (n = 4), or 1.5 mg/kg (n = 4) of methamphetamine hydrochloride as a slow intravenous (IV) bolus during continuous cardiac monitoring. The animals received the following exposures in sequence from a TASER X26 ECD beginning at 30 minutes after the administration of the drug: 1) 5-second continuous exposure, 2) 15-second intermittent exposure, 3) 30-second intermittent exposure, and 4) 40-second intermittent exposure. Darts were inserted at the sternal notch and the cardiac apex, to a depth of 9 mm. Cardiac motion was determined by thoracotomy (smaller animals, < or = 32 kg) or echocardiography (larger animals, > 68 kg). Data were analyzed using descriptive statistics and chi-square tests.</AbstractText>Animals given methamphetamine demonstrated signs of methamphetamine toxicity with tachycardia, hypertension, and atrial and ventricular ectopy in the 30-minute period immediately after administration of the drug. Smaller animals (n = 8, < or = 32 kg, mean = 29.4 kg) had supraventricular dysrhythmias immediately after the ECD exposures. Larger animals (n = 8, > 68 kg, mean = 72.4) had only sinus tachycardia after the exposures. One of the smaller animals had frequent episodes of ventricular ectopy after two exposures, including runs of delayed onset, nonsustained six- to eight-beat unifocal and multifocal ventricular tachycardia that spontaneously resolved. This animal had significant ectopy prior to the exposures as well. Thoracotomy performed on three smaller animals demonstrated cardiac capture during ECD exposure consistent with previous animal studies. In the larger animals, none of the methamphetamine-intoxicated animals demonstrated cardiac capture. Two control sheep showed evidence of capture similar to the smaller animals. No ventricular fibrillation occurred after the exposure in any animal.</AbstractText>In smaller animals (32 kg or less), ECD exposure exacerbated atrial and ventricular irritability induced by methamphetamine intoxication, but this effect was not seen in larger, adult-sized animals. There were no episodes of ventricular fibrillation after exposure associated with ECD exposure in methamphetamine-intoxicated sheep.</AbstractText> |
5,710 | Out-of-hospital cardiac arrest in denver, colorado: epidemiology and outcomes. | The annual incidence of out-of-hospital cardiac arrest (OOHCA) in the United States is approximately 6 per 10,000 population and survival remains low. Relatively little is known about the performance characteristics of a two-tiered emergency medical services (EMS) system split between fire-based basic life support (BLS) dispersed from fixed locations and hospital-based advanced life support (ALS) dispersed from nonfixed locations. The objectives of this study were to describe the incidence of OOHCA in Denver, Colorado, and to define the prevalence of survival with good neurologic function in the context of this particular EMS system.</AbstractText>This was a retrospective cohort study using standardized abstraction methodology. A two-tiered hospital-based EMS system for the County of Denver and 10 receiving hospitals were studied. Consecutive adult patients who experienced nontraumatic OOHCA from January 1, 2003, through December 31, 2004, were enrolled. Demographic, prehospital arrest characteristics, treatment data, and survival data using the Utstein template were collected. Good neurologic survival was defined by a Cerebral Performance Categories (CPC) score of 1 or 2.</AbstractText>During the study period, 1,985 arrests occurred. Of these, 715 (36%) had attempted resuscitation by paramedics and constitute our study sample. The median age was 65 years (interquartile range = 52-78 years), 69% were male, 41% had witnessed arrest, 25% had bystander cardiopulmonary resuscitation (CPR) performed, and 30% had ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT) as their initial rhythm. Of the 715 patients, 545 (76%) were transported to a hospital, 223 (31%) had return of spontaneous circulation (ROSC), 175 (25%) survived to hospital admission, 58 (8%) survived to hospital discharge, and 42 (6%, 95% confidence interval [CI] = 4% to 8%) had a good neurologic outcome.</AbstractText>Out-of-hospital cardiac arrest survival in Denver, Colorado, is similar to that of other United States communities. This finding provides the basis for future epidemiologic and health services research in the out-of-hospital and ED settings in our community.</AbstractText> |
5,711 | Cardiocerebral resuscitation is associated with improved survival and neurologic outcome from out-of-hospital cardiac arrest in elders. | Recent studies have shown that a new emergency medical services (EMS) protocol for treating patients who suffer out-of-hospital cardiac arrest (OHCA), cardiocerebral resuscitation (CCR), significantly improves survival compared to standard advanced life support (ALS). However, due to their different physiology, it is unclear if all elders, or any subsets of elders who are OHCA victims, would benefit from the CCR protocol.</AbstractText>The objectives of this analysis were to compare survival by age group for patients receiving CCR and ALS, to evaluate their neurologic outcome, and to determine what other factors affect survival in the subset of patients who do receive CCR.</AbstractText>An analysis was performed of 3,515 OHCAs occurring between January 2005 and September 2008 in the Save Hearts in Arizona Registry. A total of 1,024 of these patients received CCR. Pediatric patients and arrests due to drowning, respiratory, or traumatic causes were excluded. The registry included data from 62 EMS agencies, some of which instituted CCR. Outcome measures included survival to hospital discharge and cerebral performance category (CPC) scores. Logistic regression evaluated outcomes in patients who received CCR versus standard ALS across age groups, adjusted for known potential confounders, including bystander cardiopulmonary resuscitation (CPR), witnessed arrest, EMS dispatch-to-arrival time, ventricular fibrillation (Vfib), and agonal respirations on EMS arrival. Predictors of survival evaluated included age, sex, location, bystander CPR, witnessed arrest, Vfib/ventricular tachycardia (Vtach), response time, and agonal breathing, based on bivariate results. Backward stepwise selection was used to confirm predictors of survival. These predictors were then analyzed with logistic regression by age category per 10 years of age.</AbstractText>Individuals who received CCR had better outcomes across age groups. The increase in survival for the subgroup with a witnessed Vfib was most prominent on those<40 years of age (3.7% for standard ALS patients vs. 19% for CCR patients, odds ratio [OR]=5.94, 95% confidence interval [CI]=1.82 to 19.26). This mortality benefit declined with age until the >or=80 years age group, which regained the benefit (1.8% vs. 4.6%, OR=2.56, 95% CI=1.10 to 5.97). Neurologic outcomes were also better in the patients who received CCR (OR=6.64, 95% CI=1.31 to 32.8). Within the subgroup that received CCR, the factors most predictive of improved survival included witnessed arrest, initial rhythm of Vfib/Vtach, agonal respirations upon arrival, EMS response time, and age. Neurologic outcome was not adversely affected by age.</AbstractText>Cardiocerebral resuscitation is associated with better survival from OHCA in most age groups. The majority of patients in all age groups who survived to hospital discharge and who could be reached for follow-up had good neurologic outcome. Among patients receiving CCR for OHCA, witnessed arrest, Vfib/Vtach, agonal respirations, and early response time are significant predictors of survival, and these do not change significantly based on age.</AbstractText>Copyright (c) 2010 by the Society for Academic Emergency Medicine.</CopyrightInformation> |
5,712 | An unusual presentation of primary renal hypokalemia-hypomagnesemia (Gitelman's syndrome). | Gitelman's syndrome, or congenital hypokalemic hypomagnesemic hypocalciuria with metabolic alkalosis, is widely described as a benign or milder variant of Bartter's syndrome and most commonly presents with transient periods of weakness and fatigue, presyncope, vertigo, ataxia, and blurred vision, though aborted sudden cardiac death has also been rarely reported. Despite this there are limited data in the literature regarding the formal cardiac evaluation of patients with Gitelman's syndrome. We present the case of a gentleman with Gitelman's syndrome who initially presented to his primary physician with symptoms suggestive of an upper respiratory tract infection and subsequently survived a ventricular fibrillation (VF) cardiac arrest in the community. We review the literature regarding possible life-threatening cardiac complications in these patients. |
5,713 | Left atrial volume combined with atrial pump function identifies hypertensive patients with a history of paroxysmal atrial fibrillation. | Identifying patients at high risk for the occurrence of atrial fibrillation is one means by which subsequent thromboembolic complications may be prevented. Left atrial enlargement is associated with progression of atrial remodeling, which is a substrate for atrial fibrillation, but impaired atrial pump function is also another aspect of the remodeling. Our objective was to differentiate patients with a history of paroxysmal atrial fibrillation using echocardiography. We studied 280 hypertensive patients (age: 66+/-7 years; left ventricular ejection fraction: 65+/-8%), including 140 consecutive patients with paroxysmal atrial fibrillation and 140 age- and sex-matched control subjects. Left atrial volume was measured using the modified Simpson method at both left ventricular end systole and preatrial contraction and was indexed to body surface area. Peak late-diastolic mitral annular velocity was measured during atrial contraction using pulsed tissue Doppler imaging as an atrial pump function. Left atrial volume index measured at left ventricular end systole had a 74% diagnostic accuracy and a 71% positive predictive value for identifying patients with paroxysmal atrial fibrillation; these values for the ratio of left atrial volume index at left ventricular end systole to the peak late-diastolic mitral annular velocity were 82% and 81%, respectively, and those for the ratio of left atrial volume index at preatrial contraction to the peak late-diastolic mitral annular velocity were 86% and 90%, respectively. In conclusion, left atrial size combined with atrial pump function enabled a more accurate diagnosis of a history of paroxysmal atrial fibrillation than conventional parameters. |
5,714 | Phase statistics approach to human ventricular fibrillation. | Ventricular fibrillation (VF) is known to be the most dangerous cardiac arrhythmia, frequently leading to sudden cardiac death (SCD). During VF, cardiac output drops to nil and, unless the fibrillation is promptly halted, death usually ensues within minutes. While delivering life saving electrical shocks is a method of preventing SCD, it has been recognized that some, though not many, VF episodes are self-terminating, and understanding the mechanism of spontaneous defibrillation might provide newer therapeutic options for treatment of this otherwise fatal arrhythmia. Using the phase statistics approach, recently developed to study financial and physiological time series, here, we reveal the timing characteristics of transient features of ventricular tachyarrhythmia (mostly VF) electrocardiogram (ECG) and find that there are three distinct types of probability density function (PDF) of phase distributions: uniform (UF), concave (CC), and convex (CV). Our data show that VF patients with UF or CC types of PDF have approximately the same probability of survival and nonsurvival, while VF patients with CV type PDF have zero probability of survival, implying that their VF episodes are never self-terminating. Our results suggest that detailed phase statistics of human ECG data may be a key to understanding the mechanism of spontaneous defibrillation of fatal VF. |
5,715 | Atrium-targeted drug delivery through an amiodarone-eluting bilayered patch. | Clinical studies have demonstrated the efficacy of oral and intravenous amiodarone therapy to prevent postoperative atrial fibrillation. However, because of significant extracardiac side effects, only high-risk patients are eligible for prophylactic amiodarone therapy. This study addressed the hypothesis that atrium-specific drug delivery through an amiodarone-eluting epicardial patch reduces vulnerability to atrial tachyarrhythmias, whereas ventricular and plasma drug concentrations are minimized.</AbstractText>Right atrial epicardiums of goats were fitted with electrodes and a bilayered patch (poly[ethylene glycol]-based matrix and poly[lactide-co-caprolactone] backing layer) loaded with amiodarone (10 mg per patch, n = 10) or without drug (n = 6). Electrophysiologic parameters (atrial effective refractory period, conduction time, and rapid atrial response to burst pacing) and amiodarone levels in plasma and tissue were measured during 1 month's follow-up.</AbstractText>Epicardial application of amiodarone-eluting patches produced persistently higher drug concentrations in the right atrium than in the left atrium, ventricles, and extracardiac tissues by 2 to 4 orders of magnitude. Atrial effective refractory period and conduction time increased, whereas rapid atrial response inducibility decreased significantly (P < .05) during the 1-month follow-up compared with that seen in animals treated with drug-free patches. Amiodarone concentrations in plasma remained undetectably low (<10 ng/mL).</AbstractText>Atrium-specific drug delivery through an amiodarone-eluting patch produces therapeutic atrial drug concentrations, whereas ventricular and systemic drug levels are minimized. This study demonstrates that sustained targeted drug delivery to a specific heart chamber is feasible and might reduce the risk for ventricular and extracardiac adverse effects. Epicardial application of amiodarone-eluting patches is a promising strategy to prevent postoperative atrial fibrillation.</AbstractText>Copyright © 2010 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.</CopyrightInformation> |
5,716 | Long-term outcome of combined valve repair and maze procedure for nonrheumatic mitral regurgitation. | The long-term outcomes of combined mitral repair and maze procedure for patients with nonrheumatic mitral regurgitation and chronic atrial fibrillation were evaluated.</AbstractText>Between June 1992 and December 2008, 187 patients underwent a combined mitral repair and maze procedure. The mean follow-up period was 7.4 ± 4.3 years. Chordal reconstruction was performed in 69 patients, leaflet resection in 91, edge-to-edge leaflet suture in 30, and ring annuloplasty in 156. In addition, a cryo-maze procedure was applied in 110, and a Cox-Kosakai maze and radiofrequency maze were applied in the others.</AbstractText>There were 2 operative deaths and the 15-year survival was 71%. The 15-year freedom from greater than grade 3 mitral regurgitation was 61%; rates of freedom from heart failure (New York Heart Association class ≥ III) and reoperations were 79% and 91%, respectively. Cardiac function was improved and left ventricular size was decreased significantly postoperatively. Multivariate analysis showed that a large left ventricular diastolic diameter (≥65 mm) was an independent risk factor for recurrent mitral regurgitation. Eleven thromboembolic episodes (0.79%/patient-year) were detected during follow-up examinations, of which 7 occurred in patients with recurrent atrial fibrillation. Sinus rhythm was regained in 86% after 6 months and in 63% after 15 years. Multivariate analysis showed that a small-voltage f wave was an independent risk factor for AF recurrence.</AbstractText>A combined mitral valve repair and maze procedure provided low rates of morbidity and mortality and led to well-preserved cardiac function. Left ventricular diastolic diameter and f-wave voltage can be accurate predictors of good long-term outcome.</AbstractText>Copyright © 2010 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.</CopyrightInformation> |
5,717 | Mutations in the cardiac transcription factor GATA4 in patients with lone atrial fibrillation. | Familial recurrence of atrial fibrillation (AF) is reported in up to 15% of patients with lone AF. Recently, it was proposed that congenital defects in the morphogenesis of the pulmonary vein myocardium are involved in genetic pathogenesis of lone AF. GATA4 is a cardiac transcription factor essentially involved in myocardial development. Mutations in GATA4 are associated with congenital cardiac malformations. To investigate whether GATA4 mutations represent a genetic origin for AF the coding region of GATA4 was sequenced in 96 patients with lone AF. We found a GATA4 mutation (M247T) in a patient with familial lone AF and atrial septal aneurysm without interatrial shunts. The mutation affects a deeply conserved domain adjacent to the first zinc finger domain of GATA4 and was not reported before. A second GATA4 mutation (A411V) was found in a female patient with sporadic lone AF. This variant was previously reported in patients with cardiac septal defects. However, no anomalies of the atrial or ventricular septa were noted in the AF patient harboring A411V. We report for the first time that mutations in the cardiac transcription factor GATA4 may represent a genetic origin of lone AF. The study proposes that lone AF may share a common genetic origin with congenital cardiac malformations. |
5,718 | Electronic health records and quality of care for heart failure. | Electronic health records (EHRs) are considered an important technology to improve the quality of health care, yet few data exist regarding their effect on delivery of evidence-based care in the outpatient setting.</AbstractText>IMPROVE HF is a prospective cohort study of 15,381 patients with HF or post myocardial infarction and left ventricular ejection fraction < or =35% cared for in 167 US outpatient cardiology practices. Baseline patient characteristics and quality data were collected by chart abstraction. To quantify care, 7 HF quality measures were assessed; practices with and without EHR were compared.</AbstractText>Among practices, 52% had EHR systems (30% EHR-only; 22% both EHR and paper) and 48% paper-only systems. Conformity with indicated care for practices with EHR systems was modestly higher for 2 of 7 quality measures compared to those without. After controlling for patient and site characteristics, use of EHR was associated with improved delivery of 3 of 7 quality measures (angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, aldosterone antagonist, and HF education), similar care for 3 measures (beta-blocker, anticoagulation for atrial fibrillation, and cardiac resynchronization therapy), and worse for 1 measure (implantable cardioverter-defibrillator).</AbstractText>These data are among the first to assess the potential influence of EHR on conformity with HF guidelines in the outpatient setting and suggest that EHR systems as currently deployed are associated with only modest differences in some, but not other, quality measures provided to HF patients compared with use of paper-only systems.</AbstractText>Copyright 2010 Elsevier Inc. All rights reserved.</CopyrightInformation> |
5,719 | Improved out-of-hospital cardiac arrest survival after the sequential implementation of 2005 AHA guidelines for compressions, ventilations, and induced hypothermia: the Wake County experience. | We assess survival from out-of-hospital cardiac arrest after community-wide implementation of 2005 American Heart Association guidelines.</AbstractText>This was an observational multiphase before-after cohort in an urban/suburban community (population 840,000) with existing advanced life support. Included were all adults treated for cardiac arrest by emergency responders. Excluded were patients younger than 16 years and trauma patients. Intervention phases in months were baseline 16; phase 1, new cardiopulmonary resuscitation 12; phase 2, impedance threshold device 6; and phase 3, full implementation including out-of-hospital-induced hypothermia 12. Primary outcome was survival to discharge. Other survival and neurologic outcomes were compared between study phases, and adjusted odds ratios with 95% confidence intervals (CIs) for survival by phase were determined by multivariate regression.</AbstractText>One thousand three hundred sixty-five cardiac arrest patients were eligible for inclusion: baseline n=425, phase 1 n=369, phase 2 n=161, phase 3 n=410. Across phases, patients had similar demographic, clinical, and emergency medical services characteristics. Overall and witnessed ventricular fibrillation and ventricular tachycardia survival improved throughout the study phases: respectively, baseline 4.2% and 13.8%, phase 1 7.3% and 23.9%, phase 2 8.1% and 34.6%, and phase 3 11.5% and 40.8%. The absolute increase for overall survival from baseline to full implementation was 7.3% (95% CI 3.7% to 10.9%); witnessed ventricular fibrillation/ventricular tachycardia survival was 27.0% (95% CI 13.6% to 40.4%), representing an additional 25 lives saved annually in this community.</AbstractText>In the context of a community-wide focus on resuscitation, the sequential implementation of 2005 American Heart Association guidelines for compressions, ventilations, and induced hypothermia significantly improved survival after cardiac arrest. Further study is required to clarify the relative contribution of each intervention to improved survival outcomes.</AbstractText>Copyright © 2009 American College of Emergency Physicians. Published by Mosby, Inc. All rights reserved.</CopyrightInformation> |
5,720 | Zoledronic acid and atrial fibrillation in cancer patients. | Treatment with a bisphosphonate was found to be associated with a significantly increased risk for atrial fibrillation (AF) in a few studies. A recent study showed that once-yearly infusions of intravenous zoledronic acid (ZA) significantly increased the risk of serious AF in postmenopausal women with osteoporosis. This study was conducted to determine the frequency of atrial fibrillation among cancer patients receiving the standard treatment of ZA.</AbstractText>Patients with bone metastases who presented to our outpatient clinic for any reason (routine control, chemotherapy, or ZA administration) were included in the study. All patients had been receiving 4 mg ZA at 4-week intervals, with each dose administered over 15 min. A short survey was completed and standard 12-lead ECG recordings were obtained.</AbstractText>One hundred and twenty-four cancer patients with documented bone metastases were evaluated. Mean age of the patients was 55 ± 13.0 years, 60% of the patients were female. Forty-one percent of the patients had breast cancer, 18% had non-small cell lung cancer, and the remainder had other solid tumors. Mean duration of ZA administration was 13.4  ± 15.0 months. Mean total cumulative dose was 54  ± 15.0 mg per patient. Sixty patients (48%) had previously been treated with anthracycline-containing regimens, and 37 (30%) had received chest radiotherapy that might affect the heart. Twenty-three percent of the patients had hypertension, 10% had diabetes mellitus, 3.7% had myocardial infarction history, 1.9% had congestive heart failure, and 1% had valvular disease; 10.5% were current smokers and 32% ex-smokers. On ECG evaluation, we observed normal sinus rhythm in 58%, sinus tachycardia in 15%, sinus bradicardia in 3.2%, and ventricular extrasystole in 5.7% of the patients. There was no AF in any of the cases.</AbstractText>There was no increase in the risk of AF frequency in cancer patients who were treated with intravenous ZA, although most of the patients had additional risk factors including previous treatment with cardiotoxic agents or with chest radiotherapy. We believe that the risk of AF is negligible in this patient population and does not affect treatment decisions.</AbstractText> |
5,721 | Catheter ablation of a difficult accessory pathway guided by coronary sinus venography and 3D electroanatomical mapping. | A 38-year-old man with history of unsuccessful catheter ablation of paraseptal accessory pathway (AP) and cardiac arrest was referred for reablation. Coronary sinus (CS) venography and detailed three-dimensional electroanatomical mapping demonstrated a large diverticulum near the CS ostium. A single radiofrequency ablation at the neck of the diverticulum eliminated conduction in the AP completely. |
5,722 | [The echocardiographic diagnostic characteristics and follow-up of apical hypertrophic cardiomyopathy.]. | To evaluate the echocardiographic features of apical hypertrophic cardiomyopathy (ApHCM).</AbstractText>Twenty-seven patients with ApHCM including 21 men and 6 women, average age (42.7 +/- 5.1) years old were followed up from 1995 to 2008 to investigate the clinical, electrocardiographic and echocardiographic features.</AbstractText>The major features of ECG were increased R amplitude (V(4) > V(5) > V(3)) and inverteted T wave (especially in V(3-5) leads and the voltage of the inverteted T waves may be up to >/= 10 mm). The major feature of echocardiography was the thickening of left ventricular apical wall to 15 - 37 (18.0 +/- 3.3) mm. The final follow up showed that the mean thickness of the apical wall was (19.7 +/- 3.7) mm. The ratio of the thickness of left ventricular apical wall to posterior wall before and after the follow up was 1.7 +/- 0.3 and 1.9 +/- 0.9 respectively, with significant statistical difference (P < 0.05). There was no difference in the left ventricular end-diastolic dimension and left ventricular ejection fraction. The main cardiovascular events were atrial fibrillation (16 cases), heart failure of NYHA III-IV class (3 cases), anterior wall myocardial infarction (1 case) and sudden death (1 case).</AbstractText>The final diagnosis of ApHCM depends on the characteristic inverteted T wave in ECG and apical hypertrophy in echocardiography. The prognosis of ApHCM is rather good for its progression is relatively slow.</AbstractText> |
5,723 | Importance of morphological changes in T-U waves during bepridil therapy as a predictor of ventricular arrhythmic event. | Although bepridil is a useful anti-arrhythmic agent for atrial fibrillation, the appearance of serious ventricular arrhythmia, such as torsades de pointes, might be a problem. In this study, T-U wave morphology was evaluated during bepridil therapy and was examined as a predictor of ventricular arrhythmic events.</AbstractText>The study population consisted of 113 patients on bepridil therapy. They were divided into 2 groups with and without ventricular arrhythmic events. Morphological changes in T-U waves were analyzed in leads V(2-5). During bepridil treatment, the QTc interval was prolonged from 0.45+/-0.01 to 0.49+/-0.01 s(1/2) in all patients (P<0.0001) and any type of T-U wave change (fused U, slurred, bifid, biphasic or negative) appeared in 73% of event-free and 100% of event groups. In univariate analysis, QTc interval before bepridil (P=0.028), a wide QRS complex (P=0.042) before bepridil, biphasic (P=0.027) or negative (P=0.002) T-U waves in the stable phase, and the new appearance of biphasic (P=0.004) or negative (P<0.0001) T-U waves exhibited significant differences. In multivariate analysis, only newly appeared negative T-U wave exhibited a significant difference (odds ratio 10.13, 95% confidence interval = 0.031-2.302, P=0.041).</AbstractText>In patients with stable bepridil treatment, a change in T-U wave morphology might be a useful predictor of ventricular arrhythmia assisting the QT interval.</AbstractText> |
5,724 | Acute toxic herbal intake in a suicide attempt and fatal refractory ventricular arrhythmia. | This report involves a 54-year-old man who died following refractory ventricular fibrillation after ingestion of a plant in a suicide attempt. Repeated direct-current cardioversions were unsuccessful and no single anti-arrhythmic agent was effective for arrhythmia control. The routine blood toxicological screening was negative. Aconitine, the main toxin of Aconitum napellus was identified using a specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. The whole blood concentration (24 microg/l) was higher than those reported in other aconitine-related deaths. The patient had found information about the life-threatening nature of such a toxic herb intake on a free medical encyclopedia online. |
5,725 | Digitalis does not improve left atrial mechanical dysfunction after successful electrical cardioversion of chronic atrial fibrillation. | This study was designed to investigate whether administration of digitalis could improve mechanical function of left atrial appendage (LAA) and left atrium prospectively in patients with atrial stunning. Fifty-four consecutive patients in whom atrial stunning was observed immediately after cardioversion of chronic atrial fibrillation (AF) were randomized into digitalis or control group for 1 week following cardioversion. Transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) were performed prior to, immediately following, 1 day after and 1 week after cardioversion to measure transmitral flow velocity and LAA flow velocity. Electrical cardioversion of AF elicited significantly slower left atrial appendage peak emptying velocity (LAA-PEV) and peak filling velocity (LAA-PFV) immediately following cardioversion in both groups. 1 day post cardioversion, there were no significant differences in transmitral E wave, A wave, E/A ratio, LAA-PEV, LAA-PFV or left atrial appendage ejection fraction (LAA-EF) between digitalis and control groups. 1 week post cardioversion, no significant differences were found in transmitral E wave, A wave, E/A ratio, LAA-PEV, LAA-PFV or LAA-EF between the two groups. The occurrence rates of spontaneous echo contrast were not significantly different between digitalis and control groups one day and one week post cardioversion. In conclusion, digitalis did not improve left atrial and appendage mechanical dysfunction following cardioversion of chronic AF. Digitalis did not prevent the development of spontaneous echo contrast in left atrial chamber and appendage. This may be due to the fact that digitalis aggravates intracellular calcium overload induced by chronic AF and has a negative effect on ventricular rate. |
5,726 | Comparison of thiopental, urethane, and pentobarbital in the study of experimental cardiology in rats in vivo. | Despite earlier research studying the influence of anesthetics in arrhythmia models, a lot of controversy remains. The aim was to compare the influence of three anesthetics (60 mg/kg thiopental, 1200 mg/kg urethane, 60 mg/kg pentobarbital intraperitoneally) on ventricular arrhythmias and to combine it with measured hemodynamic parameters to find the most suitable agent for such experiments.</AbstractText>In the model of ischemia- and reperfusion-induced arrhythmias in Sprague-Dawley rats, after left anterior descending coronary artery occlusion (7 minutes) and reperfusion (15 minutes), the following parameters have been measured or calculated: mortality index; ventricular fibrillation and tachycardia incidence and duration; systolic, diastolic, and mean arterial blood pressure; heart rate; myocardial index of oxygen consumption; and plasma creatine kinase concentration.</AbstractText>Evident depressive action of urethane on heart rate, blood pressures, and myocardial index of oxygen consumption should be reason enough to exclude it from use in such studies. Pentobarbital had no effect on arrhythmias, whereas thiopental was antiarrhythmic.</AbstractText>Pentobarbital is the most suitable anesthetic offering stable hemodynamic values during arrhythmia studies. These hemodynamic values, which were similar to physiological values in awake rats, the long arrhythmia duration during reperfusion and approximately 50% mortality index are crucial parameters for evaluating antiarrhythmic drugs.</AbstractText> |
5,727 | DEFI 2005: a randomized controlled trial of the effect of automated external defibrillator cardiopulmonary resuscitation protocol on outcome from out-of-hospital cardiac arrest. | Using automated external defibrillators (AEDs) that implement the Guidelines 2000 resuscitation protocol constrains administration of cardiopulmonary resuscitation (CPR) to <50% of AED connection time. We tested a different AED protocol aimed at increasing the CPR administered to patients with out-of-hospital cardiac arrest.</AbstractText>In a randomized controlled trial, patients with out-of-hospital cardiac arrest requiring defibrillation were treated with 1 of 2 AED protocols. In the control protocol, based on Guidelines 2000, sequences of up to 3 stacked countershocks were delivered, with rhythm analyses initially and after the first and second shocks. The study protocol featured 1 minute of CPR before the first shock, shorter CPR interruptions before and after each shock, and no stacked shocks. The primary end point was survival to hospital admission. Of 5107 out-of-hospital cardiac arrest patients connected to an AED, 1238 required defibrillation, and 845 were included in the final analysis. Study patients (n=421) had shorter preshock pauses (9 versus 19 seconds; P<0.001), had shorter postshock pauses (11 versus 33 seconds; P<0.001), and received more CPR (61% versus 48%; P<0.001) and fewer shocks (2.5 versus 2.9; P<0.001) than control patients (n=424). Similar proportions survived to hospital admission (43.2% versus 42.7%; P=0.87), survived to hospital discharge (13.3% versus 10.6%; P=0.19), achieved return of spontaneous circulation before physician arrival (47.0% versus 48.6%; P=0.65), and survived to 1 year (P=0.77).</AbstractText>Following prompts from AEDs programmed with a protocol similar to Guidelines 2005, firefighters shortened pauses in CPR and improved overall hands-on time, but survival to hospital admission of patients with ventricular fibrillation out-of-hospital cardiac arrest did not improve. Clinical Trial Registration- http://www.clinicaltrials.gov. Unique identifier: NCT00139542.</AbstractText> |
5,728 | Progression of preclinical diastolic dysfunction to the development of symptoms. | Preclinical diastolic dysfunction (PDD) has been defined as subjects with normal systolic function, diastolic dysfunction but no symptoms of heart failure (HF). The clinical phenotype and natural history of the syndrome remains poorly defined. This study's objective was to determine the clinical phenotype and progression to HF in a group of patients with normal systolic function and moderate or severe diastolic dysfunction as determinate by Doppler criteria without any clinical diagnosis of HF according to the Framingham criteria or any symptoms of HF, specifically dyspnoea, oedema or fatigue at the time of echocardiography.</AbstractText>The authors used resources of the Mayo Clinic echocardiography database to consecutively select among patients who had an echocardiogram in 2005, a cohort with moderate or severe diastolic dysfunction by Doppler criteria and EF >or=50%. Patients could not have a diagnosis of HF, or any HF symptoms-specifically dyspnoea, oedema or fatigue-at the time of echocardiography; nor grade 3 or greater valvular dysfunction (except tricuspid valve). A total of 82 patients had their medical chart reviewed. Primary endpoint was the time to the development of (1) HF according to the Framingham criteria or (2) any symptoms of dyspnoea, oedema or fatigue.</AbstractText>The mean age of the cohort of PDD subjects was 69+/-10 years with a female (67%) preponderance. Presence of hypertension was 76%, coronary artery disease was 29%, paroxysmal atrial fibrillation was 26%, estimated creatinine clearance <60 ml/min was 51%. The 2-year cumulative probability of development of HF according to the Framingham criteria was 1.9%; however, the 2-year cumulative probability of development of any symptoms was 31.1%. The 2-year cumulative probability for cardiac hospitalisation was 21.2%. Peripheral vascular disease and hypertension were independently associated with increased likelihood for the development of symptoms.</AbstractText>The study demonstrates that hypertension, hyperlipidaemia, CAD and renal dysfunction are prevalent in patients with PDD. More importantly, although the progression to the development of clinical HF over 2 years was low, there was a moderate degree of progression to development of symptoms and cardiac hospitalisations over 2 years. Based on the finding that only PVD and hypertension were independently associated with the progression to the development of symptoms in subject with PDD, the authors speculate that ventricular-arterial interaction may be important to the progression of diastolic dysfunction to the development of symptoms.</AbstractText> |
5,729 | A novel cardiac myosin-binding protein C S297X mutation in hypertrophic cardiomyopathy. | Mutations in the cardiac myosin-binding protein C gene (MYBPC3) have been reported to be associated with delayed expression of hypertrophic cardiomyopathy (HCM) and a relatively good prognosis.</AbstractText>The aim of this study was to evaluate clinical manifestations in patients with familial HCM caused by a novel nonsense mutation, S297X, in MYBPC3.</AbstractText>We analyzed the sarcomere protein genes in 93 probands with HCM.</AbstractText>The nonsense mutation S297X in MYBPC3 was present in nine subjects from two unrelated families. Eight of those nine subjects with this mutation were found to be phenotype-positive and the remaining individual was not affected phenotypically. The age range at diagnosis was 9-75 years. There was no family history of sudden death in either family. At presentation, there were various left ventricular hypertrophy (LVH) patterns, including Maron type III hypertrophy from the LV base to apex, hypertrophy confined to the anterolateral wall at the basal LV wall. Two patients showed a significant LV outflow tract gradient and one patient showed intra-right-ventricular obstruction. During follow-up, one patient was repeatedly hospitalized for the treatment of heart failure after development of paroxysmal atrial fibrillation at the age of 86 years and the remaining eight subjects were in relatively stable condition and did not require hospitalization for the treatment of HCM-related events.</AbstractText>The novel mutation S297X in MYBPC3 causes HCM in a broad range of ages and heterogeneous clinical manifestations, though the clinical course in patients with this mutation seems to be benign.</AbstractText>Copyright 2010 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.</CopyrightInformation> |
5,730 | What variables were associated with the inducibility of ventricular fibrillation during electrophysiologic stimulation test in patients without apparent organic heart disease? | The purpose of our study was to determine what variables were associated with ventricular fibrillation (VF) induced during electrophysiological stimulation test in patients without apparent organic heart disease.</AbstractText>Our study evaluated 77 patients (51+/-15 years) who underwent electrophysiological stimulation test, signal averaging, and Na+ channel-blocker challenge test (pilsicainide test). The subjects were divided into two groups, the Brugada group and non-Brugada group. Further, the patients were divided into three subgroups on the base of symptoms (8, 7 symptomatic; 9, 13 syncope; 28, 12 asymptomatic group; in the Brugada and non-Brugada groups, respectively). Multivariate analyses evaluated the association between baseline clinical factors and the induction of VF.</AbstractText>The inducibility of VF was significantly (p<0.0001) higher in the Brugada group (n=33, 73%) than the non-Brugada group (n=4, 13%). The multivariate analysis demonstrated that symptoms (odds ratio (OR) 31.6; 95% confidence interval (CI): 2.3-430.6; p<0.01), type 1 electrocardiogram after pilsicainide test (OR 21.3; CI: 1.7-272.2; p<0.02), and syncope (OR 13.5; CI: 1.2-158.8; p<0.05) were strongly associated with the inducibility of VF, but not with family history, type 1 electrocardiogram in control, positive in late potential, maxDeltaST elevation (>==200microV) after pilsicainide test.</AbstractText>The symptoms, syncope, and type 1 electrocardiogram after pilsicainide test were independently associated with the electrophysiological substrate of VF in patients without apparent heart disease.</AbstractText>Copyright 2010. Published by Elsevier Ltd.</CopyrightInformation> |
5,731 | Bioprosthetic mitral valve thrombosis less than one year after replacement and an ablative MAZE procedure: a case report. | Occurrence of bioprosthetic valve thrombosis less than a year after replacement is very uncommon. Here, we describe a case of a 57 year old male, who presented 10 months after receiving a bioprosthetic mitral valve replacement with a two week history of dyspnea on exertion, worsening orthopnea and decreased exercise tolerance. Echocardiography revealed severe mitral regurgitation (MR), thrombosis of the posterior mitral leaflet, left atrial (LA) mural thrombus and a depressed left ventricular ejection fraction of twenty-five percent. Given severe clot burden and decompensated heart failure (New York Heart Association - NYHA class III) repeat sternotomy was done to replace the bioprosthetic mitral valve and remove LA mural thrombus. MR was resolved postoperatively. This brief report further reviews promoting factors, established guidelines and management strategies of bioprosthetic valve thrombosis. |
5,732 | Extracorporeal membrane oxygenation as a "bridge to recovery" in a case of myotomy for myocardial bridge complicated by biventricular dysfunction. | The incidence of cardiac dysfunction after routine cardiac surgical procedures is quite high (3-5%), but the majority of patients improve using inotropic drugs or intraaortic balloon counterpulsation. However, approximately 1% of these patients do not benefit from using these supports, and they need more invasive strategies, such as ventricular assist devices. Extracorporeal membrane oxygenation (ECMO) is one of them, and it offers biventricular support, can be managed very easily and is one of the cheapest devices. We describe our experience with ECMO in a case of postocardiotomy failure after myotomy for myocardial bridge. Because of failure of medical therapy, we decided to perform surgical myotomy of the bridge and coronary artery bypass grafting of the LAD with the left internal mammary artery. Many episodes of ventricular fibrillation occurred with quick worsening of biventricular function requiring extracorporeal membrane oxygenation (ECMO) support. The pump flow was maintained at about 1.8-2 l/m(2) (about 80% of the ideal flow) in order to reduce cardiac work offering a more rapid recovery of cardiac function. ECMO support was slowly reduced because EKG progressively improved and the hemodynamic parameters were stable. ECMO was interrupted in the 4th postoperative day when mean pressure was >90 mmHg and organ perfusion was adequate. The particularity of our case was the complicated management of MB: it is very uncommon that myotomy of the LAD results in biventricular dysfunction. Our experience confirms that benign pathologies such as MB may hide life-threatening complications and that ECMO support is the simplest solution in case of biventricular dysfunction. |
5,733 | Tunnel propagation following defibrillation with ICD shocks: hidden postshock activations in the left ventricular wall underlie isoelectric window. | After near-defibrillation threshold (DFT) shocks from an implantable cardioverter-defibrillator (ICD), the first postshock activation that leads to defibrillation failure arises focally after an isoelectric window (IW). The mechanisms underlying the IW remain incompletely understood.</AbstractText>The goal of this study was to provide mechanistic insight into the origins of postshock activations and IW after ICD shocks, and to link shock outcome to the preshock state of the ventricles. We hypothesized that the nonuniform ICD field results in the formation of an intramural excitable area (tunnel) only in the left ventricular (LV) free wall, through which both pre-existing and new shock-induced wavefronts propagate during the IW.</AbstractText>Simulations were conducted using a realistic three dimensional (3D) model of defibrillation in the rabbit ventricles. Biphasic ICD shocks of varying strengths were delivered to 27 different fibrillatory states.</AbstractText>After near-DFT shocks, regardless of preshock state, the main postshock excitable area was always located within LV free wall, creating an intramural tunnel. Either pre-existing fibrillatory or shock-induced wavefronts propagated during the IW (duration of up to 74 ms) in this tunnel and emerged as breakthroughs on LV epicardium. Preshock activity within the LV played a significant role in shock outcome: a large number of preshock filaments resulted in an IW associated with tunnel propagation of pre-existing rather than shock-induced wavefronts. Furthermore, shocks were more likely to succeed if the LV excitable area was smaller.</AbstractText>The LV intramural excitable area is the primary reason for near-DFT failure. Any intervention that decreases the extent of this area will improve the likelihood of defibrillation success.</AbstractText>Copyright 2010 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
5,734 | Feasibility of in vivo transesophageal cardiac ablation using a phased ultrasound array. | Over 2.2 million Americans suffer from atrial fibrillation making it one of the most common arrhythmias. Cardiac ablation has shown a high rate of success in treating paroxysmal atrial fibrillation. Prevailing modalities for this treatment are catheter based radio-frequency ablation or surgery. However, there is measurable morbidity and significant costs and time associated with these invasive procedures. Due to these issues, developing a method that is less invasive to treat atrial fibrillation is needed. In the development of such a device, a transesophageal ultrasound applicator for cardiac ablation was designed, constructed and evaluated. A goal of this research was to create lesions in myocardial tissue using a phased array. Based on multiple factors from array simulations, transesophageal imaging devices and throat anatomy, a phased ultrasound transducer that can be inserted into the esophagus was designed and tested. In this research, a two-dimensional sparse phased array with the aperture size of 20.7 mm x 10.2 mm with flat tapered elements as a transesophageal ultrasound applicator was fabricated and evaluated with in vivo experiments. Five pigs were anesthetized; the array was passed through the esophagus and positioned over the heart. The array was operated for 8-15 min at 1.6 MHz with the acoustic intensity of 150-300 W/cm(2) resulting in both single and multiple lesions on atrial and ventricular myocardium. The average size of lesions was 5.1 +/- 2.1 mm in diameter and 7.8 +/- 2.5 mm in length. Based on the experimental results, the array delivered sufficient power to the focal point to produce ablation while not grossly damaging nearby tissue outside the target area. These results demonstrate a potential application of the ultrasound applicator to transesophageal cardiac surgery in atrial fibrillation treatment. |
5,735 | Isolated left ventricular noncompaction: a small, noncompacted segment may cause serious complications. | Isolated left ventricular noncompaction is a rare form of cardiomyopathy. Heart failure with deteriorated systolic function is the hallmark of this cardiomyopathy. Albeit it may cause ventricular tachycardia (VT) and systemic embolism, it is a rarity to see these complications in a patient with noncompaction and normal systolic functions.</AbstractText>A 78-year old female patient with a history of cerebrovascular accident admitted to our hospital with palpitation and subsequently developed cardiopulmonary arrest. Her ECG showed ventricular tachycardia degenerated into fibrillation. Echocardiography and cardiac magnetic resonance (CMR) revealed a small noncompacted segment in left ventricular apex. Ventricular tachycardia was induced in electrophysiologic study and an implantable cardioverter-defibrillator was implanted.</AbstractText>Patients with isolated left ventricular noncompaction usually present with heart failure symptoms and subsequently diagnosed with echocardiography. Rarely, it may cause ventricular tachycardia and systemic embolism in a patient with normal systolic functions and a small noncompacted segment. Noncompaction should be carefully sought in unexplained ventricular tachycardia and cerebrovascular accidents, even if heart failure is not present.</AbstractText>Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
5,736 | Glucagon-like peptide-1 (GLP-1) attenuates post-resuscitation myocardial microcirculatory dysfunction. | Post-resuscitation syndrome leads to death in approximately 2 out of every 3 successfully resuscitated victims, and myocardial microcirculatory dysfunction is a major component of this syndrome. The aim of this study was to determine if glucagon-like peptide-1 (GLP-1) improves post-resuscitation myocardial microcirculatory function.</AbstractText>Ventricular fibrillation (VF) was induced electrically in 20 anesthetized domestic swine (30-35 kg). Following 8 min of untreated VF, animals were resuscitated with aggressive advanced cardiac life support (ACLS). Animals were blindly randomized to receive a continuous infusion of either GLP-1 (10 pM/kg/min) or equal volume saline as placebo (PBO) for 4h, beginning 1 min after return of spontaneous circulation (ROSC). Left ventricular (LV) haemodynamics, LV ejection fraction, cardiac output, and coronary flow reserve (CFR) [using a standard technique of intracoronary Doppler flow measurements before and after intracoronary administration of 60 microg adenosine] were performed pre-arrest and at 1 and 4h post-resuscitation. In the present study, CFR is a measure of myocardial microcirculatory function since these swine had no obstructive coronary artery disease. Twenty-four hour post-resuscitation survival and neurological functional scores were also determined.</AbstractText>CFR was significantly increased in GLP-1-treated animals, 1h (1.79+/-0.13 in control animals vs. 2.05+/-0.12 in GLP-1-treated animals, P = <0.05) and 4h (1.82+/-0.16 in control animals vs. 2.31+/-0.13 in GLP-1-treated animals, P = <0.05) after ROSC. In addition, compared to PBO-treated animals, GLP-1 increased cardiac output 1h after ROSC (2.1+/-0.1 in control animals vs. 2.7+/-0.2 in GLP-1-treated animals, P = <0.05). There was no statistically significant difference in survival between GLP-1-treated (100%) and PBO-treated animals (78%).</AbstractText>In this swine model of prolonged VF followed by successful resuscitation, myocardial microcirculatory function was enhanced with administration of GLP-1. However, GLP-1 treatment was not associated with a clinically significant improvement in post-resuscitation myocardial function.</AbstractText>Copyright 2010 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
5,737 | Extending the use of the pacing pulmonary artery catheter for safe minimally invasive cardiac surgery. | In this study, the therapeutic use of pacing pulmonary artery catheters in association with minimally invasive cardiac surgery was evaluated.</AbstractText>A retrospective study.</AbstractText>A single institutional university hospital.</AbstractText>Two hundred twenty-four consecutive patients undergoing minimally invasive cardiac surgery through a small (5-cm) right anterolateral thoracotomy using fibrillatory arrest without aortic cross-clamping.</AbstractText>Two hundred eighteen patients underwent mitral valve surgery (97%) alone or in combination with other procedures. Six patients underwent other cardiac operations. In all patients, the pacing pulmonary artery catheter was used intraoperatively to induce ventricular fibrillation during the cooling period, and in the postoperative period it also was used in 37 (17%) patients who needed to be paced, mainly for bradyarrhythmias (51%). There were no complications related to the insertion of the catheters. Six (3%) patients experienced a loss of pacing capture, and 2 (1%) experienced another complication requiring the surgical removal of the catheter. Seven (3%) patients needed postoperative implantation of a permanent pacemaker.</AbstractText>In combination with minimally invasive cardiac surgery, pacing pulmonary artery catheters were therapeutically useful to induce ventricular fibrillatory arrest intraoperatively and for obtaining pacing capability in the postoperative period. Their use was associated with a low number of complications.</AbstractText>Copyright 2010 Elsevier Inc. All rights reserved.</CopyrightInformation> |
5,738 | The optimal phasic relationship between synchronized shock and mechanical chest compressions. | Pauses for shock delivery in chest compressions are detrimental to the success of resuscitation and may be eliminated with the use of mechanical chest compressors. However, the optimal phasic relationship between mechanical chest compression and defibrillation is still unknown. We therefore undertook a study to assess the effects of timing of defibrillation in the mechanical chest compression cycle on the defibrillation threshold (DFT) using a porcine model of cardiac arrest.</AbstractText>Ventricular fibrillation was electrically induced and untreated for 10s in 8 domestic pigs weighing between 26 and 30 kg. Mechanical chest compression was then continuously performed for 25s, followed by a biphasic electrical shock which was delivered to the animal at 6 randomized coupling phases, including a control phase, with a pre-determined energy setting. The control phase was chosen at a constant 2s following discontinued chest compression. A novel grouped up-and-down DFT testing protocol was used to compare the success rate at different coupling phases. After a recovery interval of 4 min, the testing sequence was repeated, resulting in a total of 60 test shocks delivered to each animal.</AbstractText>No difference between the delivered shock energy, voltage and current were observed among the 6 study phases. The defibrillation success rate, however, was significantly higher when shocks were delivered in the upstroke phase of mechanical chest compression.</AbstractText>Defibrillation efficacy is maximal when electrical shock is delivered in the upstroke phase of mechanical chest compression.</AbstractText>Copyright 2010 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
5,739 | Impact of acute myocardial ischemia reperfusion on the tissue and blood-borne renin-angiotensin system. | We examined the impact of acute myocardial ischemia followed by reperfusion (AMI-R) on local and circulating renin-angiotensin system (RAS) in a swine model. The mid left anterior descending artery (n = 6) was occluded for 1 h, followed by reperfusion for 2 h. Monastryl blue/triphenyl tetrazolium chloride staining identified the area-at-risk (AAR) and infarction. A second group of control animals underwent sham operations (C: n = 4). Myocardial expression of angiotensinogen (AGT), renin, chymase, angiotensin converting enzyme (ACE), angiotensin II (Ang II), Ang II type1 receptor (AT1R) and Ang II type 2 receptor (AT2R) in the AAR and the non-ischemic left ventricle (NLV) was assessed. Serum level of these proteins at baseline and at the end of reperfusion was also examined. Chymase (P < 0.05), ACE (P < 0.05), Ang II (P < 0.05), AT1R (P < 0.05) and AT2R (P < 0.05) expressions were found to be significantly higher in the AAR compared to the NLV and C whereas no significant differences were found for AGT (P = 0.58) and renin (P = 0.38). Serum concentration of ACE was significantly higher at the end of reperfusion than at baseline (P < 0.01), whereas no significant difference was found for chymase (P = 0.71), AGT (P = 0.57) and Ang II (P = 0.19). Immunohistochemistry of myocardial sections demonstrated significantly higher expression of ACE (P = 0.02), AT1R (P = 0.01), AT2R (P = 0.02) and Ang II (P < 0.01) in the AAR as compared to the NLV, whereas no significant difference was found for renin (P = 0.39). In conclusion, AMI-R resulted in significantly higher expression of specific cardiac RAS components in AAR compared to the NLV in the acute period. |
5,740 | Gender difference in arrhythmic occurrences in patients with nonischemic dilated cardiomyopathy and implantable cardioverter-defibrillator. | Previous studies indicated that women were less likely to experience ventricular arrhythmia recurrence than men among patients with coronary artery disease and implantable cardioverter defibrillator (ICD). However, it is not clear whether the risk for ventricular tachyarrhythmia is gender-dependent in patients with nonischemic dilated cardiomyopathy. This study included 173 consecutive nonischemic dilated cardiomyopathy patients with a left ventricular ejection fraction of <45% (122 men and 51 women), who received ICD therapy between 1990 and 2008. The average follow-up period was 33 +/- 28 months. There was no significant difference in event-free rates of appropriate ICD therapy between genders for all patients (P = 0.15) and by indication of ICD (primary prevention: P = 0.43, secondary prevention: P = 0.24). There was also no significant difference in event-free rates of electrical storm between genders (P = 0.17). In high-risk patients with nonischemic dilated cardiomyopathy who received ICD, there was no gender difference in the incidence of appropriate ICD therapy or electrical storm. |
5,741 | Permanent His-bundle pacing: seeking physiological ventricular pacing. | Right ventricular apical pacing can have deleterious effects and the His bundle has been widely reported to be an alternative site. This paper presents our experience with permanent His-bundle pacing (HBP).</AbstractText>Patients referred for pacemaker implants (regardless of block type) were screened to determine if temporary HBP corrected conduction dysfunctions (threshold < or =2.5 V for 1 ms) and provided infra-Hisian 1:1 conduction of at least 120 s/m. Of the 182 patients selected, HBP corrected conduction dysfunctions in 133 (73%) patients, 42 (32%) of whom were rejected for the permanent procedure due to high thresholds. His-bundle lead implantation was attempted in the remaining 91 patients and was successful in 59 (65% of all attempts, 44% of all possible cases).</AbstractText>In some patients, permanent HBP may be an alternative to right ventricular apical pacing.</AbstractText> |
5,742 | Long-term survival of routine implantable cardioverter/defibrillator recipients appears to be significantly impaired with concomitant diuretics and improved with aldosterone antagonists. | Evidence-based treatment for heart failure (HF) comprises beta-blockers, angiotensin converting enzyme inhibitors, angiotensin receptor blockers, and aldosterone receptor antagonists (ARA). Diuretics (DR) are prescribed in acute and chronic HF, but their impact on survival and ventricular tachyarrhythmias (VT/VF) is unclear. The present observational study aims to examine the influence of DR and ARA on survival and appropriate cardioverter/defibrillator (ICD) treatment episodes in routine ICD patients. In 352 consecutive ICD patients (291 men, 60 ± 12 years, LVEF 34 ± 15%, follow-up 37 ± 19 months) overall survival and the time to a first appropriate VT/VF episode were assessed. Electrograms were validated. Potassium and creatinine serum levels and the medical treatment regimen for heart failure were documented at baseline. Multivariate Cox regression analyses revealed significantly worse survival for patients with DR compared to those without DR (OR 0.24, CI 0.08-0.76, P= 0.016), whereas the group with ARA had better survival compared to patients without (OR 2.05, CI 1.02-4.10, P= 0.04). Patient groups did not differ regarding survival without incident VT/VF (DR+ vs. DR- OR 1.10, CI 0.67-1.83, P= 0.70; OR 0.66, CI 0.40-1.09, P= 0.10). Long-term survival appears to be compromised in ICD patients receiving concomitant DR, but is favorably influenced by ARA, although VT/VF incidence does not differ. Randomized analyses are warranted to assess long-term prognostic effects of DR in HF. |
5,743 | [Detection of ventricular tachycardia and ventricular fibrillation based on joint entropy]. | This is a research with the aim of using joint entropy method to analyze the dynamical complexity information on the electrocardiogram signals recording of normal sinus rhythm (NSR), ventricular tachycardia (VT) and ventricular fibrillation (VF). We included the symbolic dynamical theory and surrogate data concept in it. By calculating the joint entropy between original and surrogate time series, we quantified the dynamical complexity of original series. By computer analysis of actual heartbeat rhythm data, the rationality of joint entropy method was confirmed. The results indicated that the joint entropy values of different signals can be of use in distinguishing the NSR, VT and VF signals. |
5,744 | [Algorithm study on the three-dimensional cardiac tissue based on the model of ventricular action potential]. | Cardiac reentry is one of the important factors to induce arrhythmias. It could lead to ventricular tachycardia (VT) or even fibrillation (VF), resulting in sudden cardiac death. With the wide use of computer in the quantitative study of electrophysiology, the three-dimensional virtual heart for simulations needs to be developed imminently in computer. In this paper, numerical algorithm of the model was studied. The three-dimensional model was constructed by integrating Luo-Rudy 1991 ventricular cell model and diffusion equation. The operator splitting method was employed to solve the model. The alternate direction iterative (ADI) format and seven-point centered difference method were used for the partial differential equation. And the discrete format with second-order accuracy was taken for the boundary conditions. The results showed that the ADI format and seven-point centered difference method both could successfully figure out the membrane potential and electrical activities with good numerical stability. However, computing consumption could be greatly reduced with the ADI format, implying that the ADI method with large time step was more powerful in numerical simulations. |
5,745 | [Perioperative acquired long QT syndrome: a case report]. | Acquired long QT syndrome is a rare condition whose diagnosis is of vital importance given the risk of torsade de pointes and sudden death. This syndrome may be triggered by various events in patients with a genetic predisposition. Patients usually have a normal baseline QT interval. Some of the factors that may prolong the interval are exposure to common drugs such as antibiotics or agents used for general anesthesia. Diagnosis of the condition is essential, as is knowledge of how to manage anesthesia and prevent ventricular fibrillation, which is the most feared complication. We report the case of a man with no relevant medical history who underwent emergency surgery for a peritonsillar abscess. The patient developed long QT syndrome, with several episodes of torsade de pointes and cardiorespiratory arrest. |
5,746 | Intravenous levosimendan vs. dobutamine in acute decompensated heart failure patients on beta-blockers. | The aim of this study is to compare the effects of a 24 h intravenous infusion of levosimendan and a 48 h infusion of dobutamine on invasive haemodynamics in patients with acutely decompensated chronic NYHA class III-IV heart failure. All patients were receiving optimal oral therapy including a beta-blocker.</AbstractText>This was a multinational, randomized, double-blind, phase IV study in 60 patients; follow-up was 1 month. There was a significant increase in cardiac index and a significant decrease in pulmonary capillary wedge pressure (PCWP) at 24 and 48 h for both dobutamine and levosimendan. The improvement in cardiac index with levosimendan was not significantly different from dobutamine at 24 h (P = 0.07), but became significant at 48 h (0.44 +/- 0.56 vs. 0.66 +/- 0.63 L/min/m(2); P = 0.04). At 24 h, the reduction in the mean change in PCWP from baseline was similar for levosimendan and dobutamine, however, at 48 h the difference was more marked for levosimendan (-3.6 +/- 7.6 vs. -8.3 +/- 6.7 mmHg; P = 0.02). No difference was observed between the groups for change in NYHA class, beta-blocker use, hospitalizations, treatment discontinuations or rescue medication use. Reduction in B-type natriuretic peptide (BNP) was significantly greater with levosimendan at 48 h (P = 0.03). According to physician's assessment, the improvement in fatigue (P = 0.01) and dyspnoea (P = 0.04) was in favour of dobutamine treatment, and hypotension was significantly more frequent with levosimendan (P = 0.007). No increase in atrial fibrillation or ventricular tachycardia was seen in either group.</AbstractText>A 24 h levosimendan infusion achieved haemodynamic and neurohormonal improvement that was at least comparable at 24 h and superior at 48 h to a 48 h dobutamine infusion.</AbstractText> |
5,747 | New antiarrhythmic drugs for treatment of atrial fibrillation. | Inadequacies in current therapies for atrial fibrillation have made new drug development crucial. Conventional antiarrhythmic drugs increase the risk of ventricular proarrhythmia. In drug development, the focus has been on favourable multichannel-blocking profiles, atrial-specific ion-channels, and novel non-channel targets (upstream therapy). Molecular modification of the highly effective multichannel blocker, amiodarone, to improve safety and tolerability has produced promising analogues such as dronedarone, although this drug seems less effective than does amiodarone. Vernakalant, an atrial-selective drug with reduced proarrhythmic risk, might be useful for cardioversion in atrial fibrillation. Ranolazine, another atrial-selective agent initially developed as an antianginal, has efficacy for atrial fibrillation and is being tested in prospective clinical trials. So-called upstream therapy with angiotensin-converting enzyme and angiotensin-receptor inhibitors, statins, or omega-3 fatty acids and fish oil that target atrial remodelling could be effective, but need further clinical validation. We focus on the basic and clinical pharmacology of newly emerging antiarrhythmic drugs and non-traditional approaches such as upstream therapy for atrial fibrillation. |
5,748 | Functional atrioventricular conduction block in an elderly patient with acquired long QT syndrome: elucidation of the mechanism of block. | The long QT syndrome (LQTS) is occasionally complicated by impaired atrioventricular (AV) conduction. This form of LQTS can manifest before birth or during neonatal life, and no previous report has demonstrated LQTS complicated by impaired AV conduction in elderly patient. This case report describes an elderly patient with an acquired form of LQTS who developed ventricular fibrillation that was successfully defibrillated during admission to the hospital. Electrophysiologic study demonstrated that HV interval was 38 milliseconds and QT interval was 635 milliseconds during sinus rhythm cycle length of 1167 milliseconds. 1:1 AV conduction was maintained to a pacing cycle length of 545 milliseconds with an AH interval of 144 milliseconds, HV interval of 44 milliseconds, and right ventricular monophasic action potential duration of 360 milliseconds. However, 2:1 HV block developed at a pacing cycle length of 500 milliseconds. Intravenous administration of mexiletine decreased the cycle length of developing HV block to 360 milliseconds. |
5,749 | [Adenosine induces ventricular arrythmias in hearts with chronic chagas cardiomyopathy]. | Adenosine released during ischemia and hypoxia can induce ventricular arrhythmias. This phenomenon is also observed in Chagas disease. This study involved pharmacologic analysis of the arrhythmogenic properties of adenosine in healthy Sprague-Dawley rats (n=14) and in rats with chronic Chagas cardiomyopathy (n=14). Electrocardiographic and pharmacologic studies were performed on isolated hearts prepared using the Langendorff method. Adenosine increased ventricular arrhythmias in both groups of animals in a dose-dependent manner: 50% of chagasic rats developed ventricular fibrillation compared with 7.14% of healthy rats (P< .05). Fibrillation was prevented by A1 (i.e., DPCPX) and A2a (i.e., 8-CSC) receptor antagonists. Arrhythmia was associated with a prolonged QT interval, early depolarization, and the R-on-T and torsade de pointes phenomena. In conclusion, adenosine is a proarrythmic drug that is able to induce ventricular fibrillation in chagasic rat hearts. |
5,750 | Long-term outcome of alcohol septal ablation in patients with obstructive hypertrophic cardiomyopathy: a word of caution. | The impact of alcohol septal ablation (ASA)-induced scar is not known. This study sought to examine the long-term outcome of ASA among patients with obstructive hypertrophic cardiomyopathy.</AbstractText>Ninety-one consecutive patients (aged 54+/-15 years) with obstructive hypertrophic cardiomyopathy underwent ASA. Primary study end point was a composite of cardiac death and aborted sudden cardiac death including appropriate cardioverter-defibrillator discharges for fast ventricular tachycardia/ventricular fibrillation. Secondary end points were noncardiac death and other nonfatal complications. Outcomes of ASA patients were compared with 40 patients with hypertrophic cardiomyopathy who underwent septal myectomy. During 5.4+/-2.5 years, primary and/or secondary end points were seen in 35 (38%) ASA patients of whom 19 (21%) patients met the primary end point. The 1-, 5-, and 8-year survival-free from the primary end point was 96%, 86%, and 67%, respectively in ASA patients versus 100%, 96%, and 96%, respectively in myectomy patients during 6.6+/-2.7 years (log-rank, P=0.01). ASA patients had a approximately 5-fold increase in the estimated annual primary end point rate (4.4% versus 0.9%) compared with myectomy patients. In a multivariable model including a propensity score, ASA was an independent predictor of the primary end point (unadjusted hazard ratio, 5.2; 95% CI, 1.2 to 22.1; P=0.02 and propensity score-adjusted hazard ratio, 6.1; 95% CI, 1.4 to 27.1; P=0.02).</AbstractText>This study shows that ASA has potentially unwanted long-term effects. This poses special precaution, given the fact that ASA is practiced worldwide at increasing rate. We recommend myectomy as the preferred intervention in patients with obstructive hypertrophic cardiomyopathy.</AbstractText> |
5,751 | Predicting drug-induced slowing of conduction and pro-arrhythmia: identifying the 'bad' sodium current blockers. | The regulatory guidelines (ICHS7B) for the identification of only drug-induced long QT and pro-arrhythmias have certain limitations.</AbstractText>Conduction time (CT) was measured in isolated Purkinje fibres, left ventricular perfused wedges and perfused hearts from rabbits, and sodium current was measured in Chinese hamster ovary cells, transfected with Na(v)1.5 channels.</AbstractText>A total of 355 compounds were screened for their effects on CT: 32% of these compounds slowed conduction, 65% had no effect and 3% accelerated conduction. Lidocaine and flecainide, which slow conduction, were tested in more detail as reference compounds. In isolated Purkinje fibres, flecainide largely slowed conduction and markedly increased triangulation, while lidocaine slightly slowed conduction and did not produce significant triangulation. Also in isolated left ventricular wedge preparations, flecainide largely slowed conduction in a rate-dependent manner, and elicited ventricular tachycardia (VT). Lidocaine slightly slowed conduction, reduced Tp-Te and did not induce VT. Similarly in isolated hearts, flecainide markedly slowed conduction, increased Tp-Te and elicited VT or ventricular fibrillation (VF). The slowing of conduction and induction of VT/VF with flecainide was much more evident in a condition of ischaemia/reperfusion. Lidocaine abolished ischaemia/reperfusion-induced VT/VF. Flecainide blocked sodium current (I(Na)) preferentially in the activated state (i.e. open channel) with slow binding and dissociation rates in a use-dependent manner, and lidocaine weakly blocked I(Na).</AbstractText>Slowing conduction by blocking I(Na) could be potentially pro-arrhythmic. It is possible to differentiate between compounds with 'good' (lidocaine-like) and 'bad' (flecainide-like) I(Na) blocking activities in these models.</AbstractText> |
5,752 | The late impact of surgical skills and training on the subcoronary implantation of the Freestyle stentless bioprosthesis. | Recent data have demonstrated an impact of higher postoperative mean pressure gradient (MPG) across the subcoronary Freestyle stentless bioprosthesis on the mid-term quality of life, but not on that of survival. Thus, the question remains that, with a prolonged follow up, would an effect on duration of survival also evolve?</AbstractText>Between 1996 and 2006, a total of 939 patients underwent aortic valve replacement (AVR) for aortic stenosis with the Freestyle stentless bioprosthesis, using the subcoronary technique. A follow up was conducted by mailed questionnaires, and completed by telephone interviews in September 2008. The follow up was 99% complete and totaled 3,468 patient-years (pt-yr); the mean follow up time was 7.7 years (range: 7.3-8.1 years). The maximum follow up was 11.9 years.</AbstractText>Actuarial survival rates at five and 10 years were 73 +/- 2% and 35 +/- 4%, respectively. The cut-off gradient was identified at a postoperative MPG of 20 mmHg, where a gradient >20 mmHg had a negative impact on survival rate (p = 0.008), as indicated by the greatest fall of deviance in the Akaike information criterion. Risk factors also affecting survival rate included atrial fibrillation, diabetes, higher serum creatinine levels, greater age, left ventricular ejection fraction < or = 40%, liver insufficiency, lower body mass index, chronic obstructive pulmonary disease, and peripheral arterial disease. Risk factors for MPG >20 mmHg were a smaller valve size, a higher preoperative gradient, individual surgeons and lesser cumulative experience, and early adopters (surgeons) of the subcoronary stentless valve implantation technique.</AbstractText>A higher MPG impedes long-term survival, with the cut-off being at 20 mmHg. A higher MPG was largely influenced by the individual surgeons and their cumulative experience of using the subcoronary technique. Late adopters of the technique profited from the observations of early adopters. The standardization of a surgical technique and the identification of common pitfalls were key to optimizing the surgical outcome after stentless valve implantation.</AbstractText> |
5,753 | Elderly woman with cerebrovascular accident and refractory arrhythmias. | Fatal bilateral cerebro-vascular accident with variable atrio-ventricular blocks, atrial fibrillation and refractory tachy-arrhythmias in a previously healthy 75-years-old hypertensive female is presented. |
5,754 | [Stored electrograms in pacemakers and ICDs from St. Jude Medical]. | Stored electrograms (EGMs) significantly improve pacemaker and ICD therapy. In pacemaker systems, the main focus of stored EGMs concerns the manual control of device detection of atrial tachyarrhythmias, especially atrial fibrillation. In ICD therapy, stored EGMs allow the discrimination of adequate and inadequate detection of ventricular tachycardia. This review presents the implementation of stored EGMs in systems from St. Jude Medical and explains the mode of EGM storage and marker annotations, which are useful for interpretation of stored EGMs and to understand the way the device interprets the EGM. Clinical examples illustrate appropriate and inappropriate device classifications. |
5,755 | [Analysis of intracardial electrograms in pacemakers and ICD systems by Biotronik]. | Detailed analysis of stored electrograms is essential for the interpretation of arrhythmias, programming changes, and optimization of the medical therapy in patients with implanted pacemakers and defibrillators. The physician who cares for patients with implantable electrical devices has to be able to understand the detection and treatment algorithms of those devices. Biotronik pacemakers of newer generations are capable of storing intracardiac electrograms. Earlier devices store up to 12 electrograms of 10 s duration after certain trigger events, like atrial tachycardia or high ventricular rates. Cardiac resynchronization systems can store electrograms after patient activation with magnets in addition to the above mentioned trigger-activated electrograms. Defibrillators store intracardiac electrograms during tachycardia episodes with near-field and far-field electrograms of the right ventricular lead in addition to the markers in single and dual chamber defibrillators (in addition to an atrial electrogram) and near field electrograms of the atrial, the right, and the left ventricular electrode in addition to the markers in resynchronization systems. Each channel has a maximum storing capacity of 32 min. If there are more episodes than storing capacity, electrograms of older episodes will be overwritten, but if the newer episodes are all classified as supraventricular, the last two ventricular episodes (VT or VF) will remain in the episode memory. This article describes stored electrograms, detection, and treatment algorithms of implantable cardiac devices manufactured by Biotronik. |
5,756 | Prevalence of preoperative arrhythmias in children with delayed treatment of severe congenital heart disease. | Our aim was to determine the real importance of rhythm and conduction disorders in children with unoperated severe congenital heart disease.</AbstractText>Consecutive children with delayed treatment of severe congenital heart disease were prospectively studied for the occurrence of arrhythmias before any invasive investigation or surgical procedure was performed.</AbstractText>All 168 children were in sinus rhythm. One hundred and fifty-eight patients (94%) had no significant preoperative findings. One child with double discordance had an intermittent complete atrioventricular block, and another one had a long QT syndrome. Children with severe ventricular dysfunction had paroxysmal atrioventricular re-entry tachycardia in 3 cases and abnormally frequent premature ventricular complexes in 3 other cases. Children with severe left atrial dilatation had periods of atrial ectopic tachycardia in one case and atrial fibrillation in another case.</AbstractText>The prevalence of rhythm and conduction disorders is relatively low in children with delayed treatment of severe congenital heart disease. Only those with congenital heart disease classically combined with such disorders and those with prolonged severe ventricular dysfunction and/or atrial dilatation are at risk of developing significant arrhythmias and should undergo a preoperative assessment of arrhythmias.</AbstractText> |
5,757 | Mechanistic insights into initiation and maintenance of ventricular fibrillation: implications for catheter ablation. | This report is intended to provide an overview of the mechanism(s) of ventricular fibrillation (VF) and its relation to catheter ablation.</AbstractText>We conducted a Pubmed and Medline literature search to identify all experimental and clinical studies published in English involving the mechanisms of VF and catheter ablation for VF. We found that controversies still exist with respect to the initiation and maintenance of VF despite more than a century of research due to the complexity of this arrhythmia and the limitation of the mapping technology. However, catheter ablation targeting the triggering factor for VF has been successfully applied in some patients who experience failure of drug therapy and frequent implanted cardiac defibrillator shocks.</AbstractText>VF is frequently triggered by short-coupled monophasic ventricular premature beats. VF is characteristic of partial and temporal organization instead of a state of completely aperiodic and disordered activation. Catheter ablation targeting the triggers for VF seems to be a safe and effective means for preventing VF in some patients.</AbstractText> |
5,758 | Does the coronary disease increase the hospital mortality in patients with aortic stenosis undergoing valve replacement? | With the increase in life expectancy occurred in recent decades, it has been noted the concomitant increase in the prevalence of aortic stenosis and degenerative disease of atherosclerotic coronary artery. This study aims to evaluate the influence of atherosclerotic coronary artery disease in patients with critical aortic stenosis undergoing isolated or combined implant valve prosthesis and coronary artery by pass grafting.</AbstractText>In the period of January 2001 to March 2006, there were analyzed 448 patients undergoing isolated implant aortic valve prosthesis (Group I) and 167 patients undergoing aortic valve prosthesis implant combined with coronary artery bypass grafting (Group II). Pre- and intra-operative variables elected for analysis were: age, gender, body mass index, stroke, diabetes mellitus, chronic obstructive pulmonary disease, rheumatic fever, hypertension, endocarditis, acute myocardial infarction, smoking, Fraction of the left ventricular ejection, critical atherosclerotic coronary artery disease, chronic atrial fibrillation, aortic valve operation prior (conservative), functional class of congestive heart failure, value serum creatinine, total cholesterol, size of the prosthesis used, length and number of distal anastomoses held in myocardial revascularization, duration of cardiopulmonary bypass and aortic clamping time. The statistical study employed invariant and multivariate analysis.</AbstractText>Hospital mortality was 14.3% (64 deaths) in Group I, and 14.5% (58 deaths) in patients with atherosclerotic coronary artery disease associated criticism (Group IB) and 12.8% (six deaths) in which had this association (Group IA). Hospital mortality in Group II was 17.6% (29 deaths), and 16.1% (20 deaths) in patients undergoing implantation of prosthetic aortic valve combined to complete myocardial revascularization (Group II) and 20.9% (nine deaths) in the myocardial revascularization with incomplete (Group IIB).</AbstractText>In patients undergoing implant isolated from aortic valve prosthesis, the presence of atherosclerotic coronary artery disease associated critical in at least two arteries, influenced the hospital mortality. In patients undergoing surgical treatment combined the number of coronary arteries with critical atherosclerotic disease and extent of coronary artery bypass grafting (complete or incomplete), did not affect the hospital mortality, but the realization of more than three anastomoses in the distal myocardial revascularization interfered.</AbstractText> |
5,759 | Realistic expectations for public access defibrillation programs. | Public access defibrillation programs have increased dramatically over the past 15 years. This review will focus on their effectiveness and operational characteristics and discuss the characteristics of successful programs, which can improve outcomes.</AbstractText>Automated external defibrillators increase survival from cardiac arrest when used by a bystander. Recent studies show that the best outcomes are achieved when devices are placed in areas with a high frequency of cardiac arrest and there is ongoing supervision with emergency plans and cardiopulmonary resuscitation training. Programs are cost-effective under these circumstances, but become very inefficient when placed in areas of low risk. There are few adverse events related to the public access defibrillation programs and volunteers are not harmed. Unguided placement results in devices not being used and a decline in organizational structure of the program. As most cardiac arrests occur in the home, the impact on overall survival remains low.</AbstractText>Automated external defibrillators are highly effective at reducing death from ventricular fibrillation and easy access in public areas is most effective. Placement must be prioritized based on public health impact and characteristics of the community.</AbstractText> |
5,760 | Mesothelial cells vs. skeletal myoblasts for myocardial infarction. | Cell transplantation for the regeneration of ischemic myocardium is limited by poor graft viability and low cell retention. Omental flaps in association with growth factors and cell sheets have recently been used to increase the vascularization of ischemic hearts. This experimental study was undertaken to evaluate the hemodynamic evolution and histological modifications of infarcted myocardium treated with mesothelial cells, and to compare the results with those of hearts treated with skeletal myoblasts. Myocardial infarction was created by surgical ligature of 2 coronary branches in 34 sheep; 6 died immediately due to ventricular fibrillation. Mesothelial cells were isolated from greater omentum, and myoblasts from skeletal muscle. After expanding the cells for 3 weeks, infarcted areas were treated with culture medium (control group), mesothelial cells, or myoblasts. After 3 months, echocardiographic studies showed significant limitation of ventricular dilatation and improved ejection fractions in both cell-treated groups compared to the controls. In the mesothelial cell group, histological studies showed significantly more angiogenesis and arteriogenesis than in the control and skeletal myoblast groups. Mesothelial cells might be useful for biological revascularization in patients with ischemic heart disease. |
5,761 | Diastolic dysfunction predicts new-onset atrial fibrillation and cardiovascular events in patients with acute myocardial infarction and depressed left ventricular systolic function: a CARISMA substudy. | The aim of this study was to investigate the association between diastolic dysfunction and long-term occurrence of new-onset atrial fibrillation (AF) and cardiac events in patients with acute myocardial infarction (AMI) and left ventricular (LV) systolic dysfunction.</AbstractText>The study was performed as a substudy on the CARISMA study population. The CARISMA study enrolled 312 patients with an AMI and LV ejection fraction <or=40%. Patients were implanted with an implantable loop recorder and followed for 2 years. Sixty-two patients had a full echocardiographic assessment of the diastolic function using tissue Doppler analysis performed 6 weeks after the AMI. The endpoints were: (i) new-onset AF and (ii) major cardiovascular events (MACE) defined as re-infarction, stroke, or cardiovascular death. Twenty-four patients had diastolic dysfunction, whereas 38 patients had normal diastolic function. Diastolic dysfunction was associated with an increased risk of new-onset AF [HR = 5.30 (1.68-16.75), P = 0.005] and MACE [HR = 4.70 (1.25-17.75), P = 0.022] after adjustment for age, sex, NYHA class, and hypertension.</AbstractText>Diastolic dysfunction in post-MI patients with LV systolic dysfunction predisposes to new-onset AF and MACE.</AbstractText> |
5,762 | Registration of 4D cardiac CT sequences under trajectory constraints with multichannel diffeomorphic demons. | We propose a framework for the nonlinear spatiotemporal registration of 4D time-series of images based on the Diffeomorphic Demons (DD) algorithm. In this framework, the 4D spatiotemporal registration is decoupled into a 4D temporal registration, defined as mapping physiological states, and a 4D spatial registration, defined as mapping trajectories of physical points. Our contribution focuses more specifically on the 4D spatial registration that should be consistent over time as opposed to 3D registration that solely aims at mapping homologous points at a given time-point. First, we estimate in each sequence the motion displacement field, which is a dense representation of the point trajectories we want to register. Then, we perform simultaneously 3D registrations of corresponding time-points with the constraints to map the same physical points over time called the trajectory constraints. Under these constraints, we show that the 4D spatial registration can be formulated as a multichannel registration of 3D images. To solve it, we propose a novel version of the Diffeomorphic Demons (DD) algorithm extended to vector-valued 3D images, the Multichannel Diffeomorphic Demons (MDD). For evaluation, this framework is applied to the registration of 4D cardiac computed tomography (CT) sequences and compared to other standard methods with real patient data and synthetic data simulated from a physiologically realistic electromechanical cardiac model. Results show that the trajectory constraints act as a temporal regularization consistent with motion whereas the multichannel registration acts as a spatial regularization. Finally, using these trajectory constraints with multichannel registration yields the best compromise between registration accuracy, temporal and spatial smoothness, and computation times. A prospective example of application is also presented with the spatiotemporal registration of 4D cardiac CT sequences of the same patient before and after radiofrequency ablation (RFA) in case of atrial fibrillation (AF). The intersequence spatial transformations over a cardiac cycle allow to analyze and quantify the regression of left ventricular hypertrophy and its impact on the cardiac function. |
5,763 | Impact of preoperative atrial fibrillation on the late outcome of off-pump coronary artery bypass surgery. | The impact of pre-existing atrial fibrillation on the long-term outcome in patients after off-pump coronary revascularisation is not well known. This study aims to determine the independent effects of preoperative atrial fibrillation on the early and late outcomes of off-pump coronary artery bypass surgery.</AbstractText>A total of 513 patients undergoing isolated coronary artery bypass surgery using off-pump approach between 2000 and 2005 were studied. Twenty-six of them (5.1%) had preoperative atrial fibrillation (15 had paroxysmal atrial fibrillation and 11 had persistent or permanent atrial fibrillation) and the other 487 patients were in normal sinus rhythm. Early and late outcomes were compared retrospectively between patients with preoperative atrial fibrillation and patients in sinus rhythm. The median follow-up period for the entire study population was 3.3 + or - 2.7 years.</AbstractText>The baseline characteristics of the patients with preoperative atrial fibrillation were generally similar to those of patients in sinus rhythm. However, the patients with atrial fibrillation had a significantly lower left ventricular ejection fraction compared with those in sinus rhythm (50 + or - 15 vs 56 + or - 12%, p=0.03). The mean age of the atrial fibrillation group was almost 3 years more than that of the sinus rhythm group. Operative mortality was similar in patients with atrial fibrillation (3.8%) and those in sinus rhythm (1.0%). Ten patients developed cerebral infarction within 7 days after surgery, including one patient (3.8%) from the atrial fibrillation group and nine patients (1.8%) from the sinus rhythm group. Long-term survival was significantly decreased in the atrial fibrillation group (5-year survival: 70 + or - 9.6% vs 87 + or - 1.8%; p=0.0018). Freedom from cerebral complications was also significantly decreased in the atrial fibrillation group (5-year survival: 85 + or - 8.3% vs 95 + or - 1.2%; p=0.0009), but there were no differences in cardiac death and major cardiac adverse events. On Cox proportional hazards regression analysis, preoperative atrial fibrillation was a significant adverse predictor for survival (hazard ratio=3.0, 95% confidence intervals (CIs) 1.3-6.9; p=0.009) and independent predictor of late cerebral infarction (hazard ratio=6.2, 95% CIs 2.0-19.3; p=0.0002).</AbstractText>Uncorrected preoperative atrial fibrillation is strongly associated with poor long-term survival and increased late cerebral complications after off-pump coronary artery bypass surgery. Concomitant atrial fibrillation surgery should be considered to improve the long-term results of surgical revascularisation.</AbstractText>Copyright 2010 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.</CopyrightInformation> |
5,764 | Primary isolated aortic valve surgery in octogenarians. | We reviewed our surgery registry, to identify predictive risk factors for operative results, and to analyse the long-term survival outcome in octogenarians operated for primary isolated aortic valve replacement (AVR).</AbstractText>A total of 124 consecutive octogenarians underwent open AVR from January 1990 to December 2005. Combined procedures and redo surgery were excluded. Selected variables were studied as risk factors for hospital mortality and early neurological events. A follow-up (FU; mean FU time: 77 months) was obtained (90% complete), and Kaplan-Meier plots were used to determine survival rates.</AbstractText>The mean age was 82+/-2.2 (range: 80-90 years; 63% females). Of the group, four patients (3%) required urgent procedures, 10 (8%) had a previous myocardial infarction, six (5%) had a previous coronary angioplasty and stenting, 13 patients (10%) suffered from angina and 59 (48%) were in the New York Heart Association (NYHA) class III-IV. We identified 114 (92%) degenerative stenosis, six (5%) post-rheumatic stenosis and four (3%) active endocarditis. The predicted mortality calculated by logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) was 12.6+/-5.7%, and the observed hospital mortality was 5.6%. Causes of death included severe cardiac failure (four patients), multi-organ failure (two) and sepsis (one). Complications were transitory neurological events in three patients (2%), short-term haemodialysis in three (2%), atrial fibrillation in 60 (48%) and six patients were re-operated for bleeding. Atrio-ventricular block, myocardial infarction or permanent stroke was not detected. The age at surgery and the postoperative renal failure were predictors for hospital mortality (p value <0.05), whereas we did not find predictors for neurological events. The mean FU time was 77 months (6.5 years) and the mean age of surviving patients was 87+/-4 years (81-95 years). The actuarial survival estimates at 5 and 10 years were 88% and 50%, respectively.</AbstractText>Our experience shows good short-term results after primary isolated standard AVR in patients more than 80 years of age. The FU suggests that aortic valve surgery in octogenarians guarantees satisfactory long-term survival rates and a good quality of life, free from cardiac re-operations. In the era of catheter-based aortic valve implantation, open-heart surgery for AVR remains the standard of care for healthy octogenarians.</AbstractText>Copyright 2010 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.</CopyrightInformation> |
5,765 | Validation of a cutoff value on echo Doppler analysis to replace right heart catheterization during pulmonary hypertension evaluation in heart transplant candidates. | Heart transplantation (OHT) has traditionally been contraindicated in the presence of severe pulmonary hypertension (PH), as detected by right heart catheterization. Noninvasive methods are still not reliably accurate to make this evaluation.</AbstractText>Determine the efficacy of echo Doppler analysis for the diagnosis of severe PH.</AbstractText>One hundred thirty patients (mean age = 42 +/- 15 years, 82 men) showed severe left ventricular dysfunction (mean ejection fraction = 29 +/- 12%; functional class III-IV). We excluded patients with atrial fibrillation, heart failure secondary to congenital disease, and valvulopathy. The pulmonary parameters defined as severe PH were: systolic pulmonary artery pressure (sPAP) >or= 60 mm Hg; a mean transpulmonary gradient >or= 15; or pulmonary vascular resistance >or= 5 Wood units. Patients underwent a right heart catheterization using a Swan-Ganz catheter to measure hemodynamic parameters and to noninvasively estimate right-sided pressures from spectral Doppler recordings of tricuspid regurgitation velocity (right ventricular systolic pressure [RVsP]). A Pearson correlation of sPAP was obtained with RVsP by; the sensitivity of RVsP for the diagnosis of PH was determined by a receiver operating characteristic (ROC) curve.</AbstractText>A good correlation between sPAP and RVsP was obtained by Pearson correlation analysis (r = 0.64; 95% confidence interval [CI] 0.50-0.75; P < .001). The ROC curve analysis showed a sensitivity of 100%, a specificity of 37.2%, (95% CI 0.69-0.83, P < .0001) of a RVsP < 45 mm Hg (cutoff) on the exclusion of severe PH.</AbstractText>The cutoff of RVsP < 45 mm Hg, on noninvasive echo Doppler evaluation of PH is an efficient method to replace invasive heart catheterization in OHT candidates.</AbstractText>Copyright (c) 2010 Elsevier Inc. All rights reserved.</CopyrightInformation> |
5,766 | The clinical course of acute ST-elevation myocardial infarction in patients with hypertension. | Arterial hypertension has been documented as one the cardiovascular risk factors. The issue whether hypertension worsens the clinical course and short-term prognosis of patients with acute ST-elevation myocardial infarction (STEMI) has been addressed by several studies, however, the results were not uniform.</AbstractText>To compare the clinical course and short-term prognosis in STEMI patients with or without hypertension.</AbstractText>The study group consisted of 366 patients with STEMI, of whom 234 (63.9%) had a history of hypertension (150 males, mean age 58.5+/-11.2 years) whereas 132 (100 males, mean age 60.3+/-11.9) did not. All patients underwent primary angioplasty with stent implantation. Details from medical history, cardiovascular risk factors, clinical course and in-hospital complications were recorded and compared between patients with and without hypertension.</AbstractText>There were differences between both study groups in the prevalence of cardiovascular risk factors. Patients with hypertension had more frequently history of coronary artery disease (56 vs. 37%, p<0.01), BMI>25 kg/m2 (90 vs. 85%, p<0.01), type 2 diabetes (27 vs. 14%, p<0.05), hyperlipidaemia (56 vs. 43%, p<0.05), and renal disease (11 vs. 5%, p<0.05). Clinical course of MI was more complicated in patients with hypertension who had more often cardiogenic shock (10 vs. 6%, p<0.05), pulmonary oedema (12 vs. 4%, p<0.05), sinus tachycardia>90 beats/min on admission (12 vs. 4%, p<0.05), ventricular tachycardia or fibrillation (20 vs. 11%, p<0.01) and complete atrioventricular block (11 vs. 4%, p<0.01). In-hospital deaths occurred in 18 (7.7%) patients with hypertension and 7 (5.3%) patients without hypertension (NS). Multivariate analysis identified age>65 years, symptoms of heart failure, atrial fibrillation, elevated blood glucose level and creatinine level as independent prognostic factors of adverse outcome in both groups whereas history of stroke, increased while cell blood count, urea level and two-vessel disease where independent prognostic variables in patients with hypertension. Ventricular tachycardia or fibrillation had prognostic significance only in STEMI patients without hypertension.</AbstractText>Patients with STEMI and hypertension have more cardiovascular risk factors and more complicated in-hospital course of MI than normotensive patients.</AbstractText> |
5,767 | Determinants of physical fitness in males with systolic heart failure. | Heart failure (HF) is a systemic disease which affects mainly older adults. The main symptom of HF is exercise intolerance which in the course of disease can cause limitations in independent functioning. So far no study on the impact of HF on physical fitness in men, regardless of disease severity, has been reported.</AbstractText>To evaluate physical fitness in men with HF independently of age, HF severity, concomitant diseases and pharmacological treatment.</AbstractText>The study group consisted of 228 men with stable systolic dysfunction (age 60+/-11, left ventricular ejection fraction--LVEF 29+/-9%, NYHA class I/II/III/IV--17/44/35/4%). In order to assess physical fitness the Functional Fitness Test by Rikli and Jones for older adults was used.</AbstractText>The level of physical fitness decreased with age. Patients with greater severity of HF had worse aerobic endurance, agility and muscular endurance in comparison with men in NYHA classes I-II. A lower level of agility and dynamic balance was found in patients with higher concentration of NT-proBNP and lower levels of haemoglobin and eGFR. Coexisting atrial fibrillation and diabetes mellitus were associated with decreased physical fitness. No relationship between flexibility and clinical parameters or concomitant diseases was found in the study group.</AbstractText>The most important determinants of physical fitness in men with HF were age and NYHA class. Additional factors which decreased physical fitness were atrial fibrillation and diabetes mellitus. Higher level of NT-proBNP and lower levels of haemoglobin were associated with a reduction of upper body strength and aerobic endurance.</AbstractText> |
5,768 | Atypical ST segment elevation and ventricular fibrillation without structural heart disease: a new electrocardiographic presentation of a channelopathy? | Primary electrical syndromes are a group of rare inherited diseases that predispose to arrhythmias in the absence of structural abnormalities of the heart, and are associated with several ion channel mutations. Extrinsic factors, such as fever, may contribute to the development of electrical instability in these patients. We report the case of a 52-year-old patient who was admitted for syncope and had an in-hospital episode of ventricular fibrillation, who presented with an admission ECG showing marked precordial ST segment elevation (maximum 5 mm in V2). The patient did not have structural heart disease and during the hospital stay there was progressive ST segment normalization, with features suggestive of Brugada pattern. An automated defibrillator was implanted for secondary prevention of sudden cardiac arrest. We believe that these findings may represent a new form of presentation of a genetic electrical syndrome. |
5,769 | Percutaneous mitral valve repair with the MitraClip system: acute results from a real world setting. | This study sought to evaluate the feasibility and early outcomes of a percutaneous edge-to-edge repair approach for mitral valve regurgitation with the MitraClip system (Evalve, Inc., Menlo Park, CA, USA). METHODS AND RESULTS PATIENTS: were selected for the procedure based on the consensus of a multidisciplinary team. The primary efficacy endpoint was acute device success defined as clip placement with reduction of mitral regurgitation to < or =2+. The primary acute safety endpoint was 30-day freedom from major adverse events, defined as the composite of death, myocardial infarction, non-elective cardiac surgery for adverse events, renal failure, transfusion of >2 units of blood, ventilation for >48 h, deep wound infection, septicaemia, and new onset of atrial fibrillation. Thirty-one patients (median age 71, male 81%) were treated between August 2008 and July 2009. Eighteen patients (58%) presented with functional disease and 13 patients (42%) presented with organic degenerative disease. A clip was successfully implanted in 19 patients (61%) and two clips in 12 patients (39%). The median device implantation time was 80 min. At 30 days, there was an intra-procedural cardiac tamponade and a non-cardiac death, resulting in a primary safety endpoint of 93.6% [95% confidence interval (CI) 77.2-98.9]. Acute device success was observed in 96.8% of patients (95% CI 81.5-99.8). Compared with baseline, left ventricular diameters, diastolic left ventricular volume, diastolic annular septal-lateral dimension, and mitral valve area significantly diminished at 30 days.</AbstractText>Our initial results with the MitraClip device in a very small number of patients indicate that percutaneous edge-to-edge mitral valve repair is feasible and may be accomplished with favourable short-term safety and efficacy results.</AbstractText> |
5,770 | Terlipressin versus adrenaline in an infant animal model of asphyxial cardiac arrest. | The objective of this study was to compare the efficacy of terlipressin versus adrenaline in an experimental infant animal model of asphyxial cardiac arrest (ACA).</AbstractText>Prospective randomised animal study.</AbstractText>Laboratory research department of a university hospital.</AbstractText>Seventy-one, 2-month-old, mechanically ventilated piglets were investigated. ACA was induced by removal of mechanical ventilation. Resuscitation was performed by means of manual external chest compressions and mechanical ventilation (CC + V). After 3 min of CC + V, return of spontaneous circulation (ROSC) was observed in 11 animals. The 60 piglets without ROSC were then randomised to the four study groups: adrenaline standard dose (Asd): 0.01 mg/kg/3 min; adrenaline high dose (Ahd): first dose (0.01 mg/kg) and subsequent doses (0.1 mg/kg/3 min); terlipressin (T): 20 microg/kg/6 min; and adrenaline standard dose plus terlipressin (Asd + T).</AbstractText>The relationship between haemodynamic (heart rate, blood pressure, ECG rhythm, cardiac index), respiratory (end-tidal CO(2), blood gas analysis) and tissue perfusion (gastric intramucosal pH, central, cerebral and renal saturation) parameters and ROSC was analysed. ROSC was achieved in three piglets treated with Asd (20%), four treated with Ahd (26.7%), one treated with T (6.7%) and seven treated with Asd + T (46.7%) (P = 0.099). ROSC was achieved in 43.1% of animals with pulseless electrical activity, 30.4% with asystole and none with ventricular fibrillation (P = 0.0001).</AbstractText>In this infant animal model of cardiac arrest, there was a non-significant trend towards better outcome when terlipressin was combined with adrenaline compared with the use of adrenaline or terlipressin alone.</AbstractText> |
5,771 | Nationwide public-access defibrillation in Japan. | It is unclear whether dissemination of automated external defibrillators (AEDs) in public places can improve the rate of survival among patients who have had an out-of-hospital cardiac arrest.</AbstractText>From January 1, 2005, through December 31, 2007, we conducted a prospective, population-based, observational study involving consecutive patients across Japan who had an out-of-hospital cardiac arrest and in whom resuscitation was attempted by emergency responders. We evaluated the effect of nationwide dissemination of public-access AEDs on the rate of survival after an out-of-hospital cardiac arrest. The primary outcome measure was the 1-month rate of survival with minimal neurologic impairment. A multivariate logistic-regression analysis was performed to assess factors associated with a good neurologic outcome.</AbstractText>A total of 312,319 adults who had an out-of-hospital cardiac arrest were included in the study; 12,631 of these patients had ventricular fibrillation and had an arrest that was of cardiac origin and that was witnessed by bystanders. In 462 of these patients (3.7%), shocks were administered by laypersons with the use of public-access AEDs, and the proportion increased, from 1.2% to 6.2%, as the number of public-access AEDs increased (P<0.001 for trend). Among all patients who had a bystander-witnessed arrest of cardiac origin and who had ventricular fibrillation, 14.4% were alive at 1 month with minimal neurologic impairment; among patients who received shocks from public-access AEDs, 31.6% were alive at 1 month with minimal neurologic impairment. Early defibrillation, regardless of the type of provider (bystander or emergency-medical-services personnel), was associated with a good neurologic outcome after a cardiac arrest with ventricular fibrillation (adjusted odds ratio per 1-minute increase in the time to administration of shock, 0.91; 95% confidence interval, 0.89 to 0.92; P<0.001). The mean time to shock was reduced from 3.7 to 2.2 minutes, and the annual number of patients per 10 million population who survived with minimal neurologic impairment increased from 2.4 to 8.9 as the number of public-access AEDs increased from fewer than 1 per square kilometer of inhabited area to 4 or more.</AbstractText>Nationwide dissemination of public-access AEDs in Japan resulted in earlier administration of shocks by laypersons and in an increase in the 1-month rate of survival with minimal neurologic impairment after an out-of-hospital cardiac arrest.</AbstractText>2010 Massachusetts Medical Society</CopyrightInformation> |
5,772 | QRS duration is associated with atrial fibrillation in patients with left ventricular dysfunction. | QRSduration (QRSd) is associated with higher mortality and morbidity in patients with left ventricular (LV) dysfunction. The association between QRSd and atrial fibrillation (AF) has not been studied in this patient population.</AbstractText>To investigate the association between QRSd and AF in patients with LV dysfunction.</AbstractText>Data were obtained from the National Registry to Advance Heart Health (ADVANCENT) registry, a prospective multicenter registry of patients with left ventricular ejection fraction (LVEF) < or = 40%. A total of 25 268 patients from 106 centers in the United States, were enrolled between June 2003 and November 2004. Demographic and clinical characteristics of patients were collected from interviews and medical records.</AbstractText>: Mean age was 66.3+/-13 years, 71.5% were males, and 81.9% were white. A total of 14 452 (57.8%) patients had a QRSd < 120 ms, 5304 (21.2%) had a QRSd between 120 and 150 ms, and 5269 (21%) had a QRSd > 150 ms. Atrial fibrillation occurred in 20.9%, 27.5%, and 35.5% of patients in the QRS groups, respectively (P < 0.0001). After adjusting for potential AF risk factors (age, gender, race, body mass index, hypertension, diabetes, renal failure, cancer, lung disease, New York Heart Association [NYHA] class, ejection fraction, etiology of cardiomyopathy) and the use of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, beta-blockers, and lipid lowering drugs, QRS duration remained independently associated with AF (odds ratio: 1.20, 95% confidence interval: 1.14-1.25).</AbstractText>In this large cohort of patients, QRSd was strongly associated with AF and therefore may predict the occurrence of this arrhythmia in patients with LV dysfunction. This association persisted after adjusting for disease severity, comorbid conditions, and the use of medications known to be protective against AF.</AbstractText>Copyright (c) 2010 Wiley Periodicals, Inc.</CopyrightInformation> |
5,773 | TGF-beta1 expression and atrial myocardium fibrosis increase in atrial fibrillation secondary to rheumatic heart disease. | Atrial fibrosis was considered a structural basis for the development and sustaining of atrial fibrillation (AF). Transforming growth factor-beta1 (TGF-beta1) was one of the main factors for accelerating collagen production. The contribution of TGF-beta1 in the pathogenesis of AF needs further investigation.</AbstractText>The altered expression and distribution of TGF-beta1 will be associated with the changes in atrial fibrosis in different types of AF patients with rheumatic heart disease (RHD).</AbstractText>Right atrial specimens obtained from 38 RHD patients undergoing mitral valve replacement surgery were divided into 3 groups: the sinus rhythm group (n = 8), the paroxysmal AF group (pAF; n = 10), and the chronic AF group (cAF; AF lasting >/= 6 mo; n = 20). The degree of atrial fibrosis, collagen content, serum levels, messenger RNA (mRNA), and protein expression of TGF-beta1 were detected.</AbstractText>The collagen content, serum level, TGF-beta1 mRNA, and protein expression of the atrial tissue increased gradually in sinus rhythm, for both pAF and cAF groups, respectively. A positive correlation between TGF-beta1 and the degree of atrial fibrosis was also demonstrated (P < 0.05).</AbstractText>The TGF-beta1 expression in atrial tissue increased gradually in proportion to the degree of atrial fibrosis in AF and was associated with the type of AF, which suggests that TGF-beta1 is possibly involved in the pathogenesis of AF in RHD patients.</AbstractText>Copyright (c) 2010 Wiley Periodicals, Inc.</CopyrightInformation> |
5,774 | Attenuation of post-shock increases in brain natriuretic Peptide with post shock overdrive pacing. | Predischarge defibrillation threshold testing is often performed a few days after ICD implantation in order to validate defibrillation thresholds obtained at the time of implant. Ventricular fibrillation is induced with such testing and causes an increase in serum Brain Natriuretic Peptide (BNP) levels. BNP is an indicator for cardiac stress. We wanted to examine the feasibility to alter the trend of BNP after predischarge testing in VVI, DDD and CRT ICD's.</AbstractText>We measured BNP before predischarge testing and 5, 10, 20 and 40 minutes after predischarge testing in 13 groups with each 20 patients. We evaluated patients without post shock pacing and patients with a post shock pacing frequency of 60, 70, 80, 90 and 100 bpm and a duration of 30 and 60 sec as well as a post shock pacing frequency of 80 and 90 bpm and a duration of 120 sec post shock pacing.</AbstractText>Patients without post shock pacing showed the highest BNP during the follow-up. The percentage values of BNP increased consistent significantly after 5 minutes compared with BNP before predischarge testing. The percentage values of BNP trend was significantly lower with a post shock pacing of 90 bpm and duration of 60 sec. In addition, we excluded a cardiac necrosis by predischarge testing because of similar values of myoglobin, cardiac troponin I and creatine kinase during the follow-up.</AbstractText>Our results suggested that post shock pacing with 90 bpm and duration of 60 sec as the best optimized post shock pacing frequency and duration for VVI, DDD and CRT ICD's. A reduction of cardiac stress is going to be achieved with the optimization of the post shock pacing frequency and duration.</AbstractText> |
5,775 | Effects of metabolic syndrome on early mortality and morbidity in coronary artery bypass graft patients. | Metabolic syndrome is a well-known cardiovascular risk factor closely related to increased insulin resistance. This study assessed the effects of metabolic syndrome on early post-operative mortality and morbidity in 100 coronary artery bypass graft (CABG) patients: 50 patients with and 50 without metabolic syndrome. A total of 17 patients were excluded from the analysis as they did not attend follow-up, leaving 51 males (61.4%) and 32 (38.6%) females of mean +/- SD age 60.02 +/- 9.76 years for analysis. Diabetes, hypertension and a high body mass index were significantly more common in patients with metabolic syndrome. A statistically significant relationship was found between metabolic syndrome and surgical wound infection. Non-significant positive correlations were found between metabolic syndrome and post-operative atrial fibrillation, surgical revision due to haemorrhage, ventricular tachycardia and ventricular fibrillation, and prolonged intubation. In conclusion, metabolic syndrome did not affect mortality, but did increase the risk of post-operative surgical wound infection. |
5,776 | Inappropriate shock despite successful termination of supraventricular tachycardia by antitachycardia pacing during charging. | We present a case of a 70-year-old man who received an inappropriate implantable cardioverter-defibrillator shock for sinus tachycardia falling outside of the ventricular tachycardia zone. This occurred after termination of supraventricular tachycardia falling into the ventricular fibrillation zone by antitachycardia pacing. Particularities of the programming algorithms are reviewed. |
5,777 | A phenotypic combination of idiopathic VF and Brugada syndrome. | This case study shows a young male presenting a mixture of two disease entities: (1) Brugada syndrome with a nearly-normal baseline electrocardiogram and positive Ajmaline drug challenge as well as (2) idiopathic ventricular fibrillation including extremely short-coupled monomorphic ventricular premature beats (VPB) triggering ventricular fibrillation (coupling interval 318 ± 21 ms). In this phenotypic patient group-more suggestive of idiopathic ventricular fibrillation due to the ultra-short coupling interval of the VPBs-drug treatment with a class IA agent such as Quinidine might be an important option to implantable cardioverter-defibrillator and ablation therapy. |
5,778 | Actual pacemaker longevity: the benefit of stimulation by automatic capture verification. | We evaluated the impact of an algorithm for automatic right ventricular (RV) stimulation compared to fixed-output pacing (FOP) stimulation on actual pacemaker longevity over a 9-year follow-up.</AbstractText>Prospective observation of 300 patients implanted with VDDR/DDDR pacemakers in 1999-2000 up to October 31, 2008. Sixty-one patients were paced by Autocapture pacing (ACP), 239 were paced by FOP; they were seen twice yearly at the pacemaker clinic. Factors known to affect pacemaker longevity were collected: median heart rate, %A&V paced activity, pacing output, and impedance. Patients dead before pacemaker replacement, lost to follow-up, or who developed permanent atrial fibrillation were excluded from analysis.</AbstractText>One hundred twenty-six of three hundred patients completed the study. Adverse clinical events due to an increased RV threshold occurred in two FOP patients compared to none among ACP. Pacemaker replacement occurred in 1/34 ACP patients versus 60/92 FOP patients (P < 0.001). ACP was the single independent predictor of pacemaker longevity at multivariable analysis (hazard ratio = 0.03, P < 0.001) either in the overall population or in the specific patients subgroups (sick sinus syndrome, atrioventricular block, and neurally mediated syncope).</AbstractText>Automatic verification of stimulation is reliable at long term, and warrants superior safety in the event of pacing threshold changes. It allows a significant longevity increase compared to FOP stimulation that may heavily impact the patients' quality of life and the cost of pacing therapy. Moreover, it is a fundamental technology in a strategy of remote patient and device monitoring, and may enable automatic device follow-up operated by trained, nonmedical personnel.</AbstractText> |
5,779 | [Stored electrograms in pacemakers and ICDs]. | Stored electrograms (EGMs) represent an important development in pacemaker and ICD therapy. The most important issue in pacemaker EGMs is the confirmation of the detection of atrial tachyarrhythmias, especially atrial fibrillation. In ICD therapy, the discrimination between ventricular and supraventricular tachycardia (i.e., detection of inadequate therapy) is of central interest. Unfortunately, systematic"instructions" for interpreting stored EGMs in systems by different manufacturers are not available and the knowledge on this topic is limited to (too) few experts. The contributions in this issue aim at explaining the interpretation of stored EGMs in systems by different manufacturers, providing an understanding of marker annotations and EGM registrations in clinical examples. With the aim of improving pacemaker and ICD therapy, a broad distribution of knowledge on the usefulness and the practical use of stored EGMs is highly desirable. |
5,780 | Sleep apnea in heart failure patients. | Growing evidence suggests that there may be a strong pathophysiologic link between congestive heart failure (CHF) and nocturnal breathing disorders due to nocturnal oxygen desaturation, intrathoracic pressure swings and sympathetic activation. It seems that sleep apnea contributes to systolic and diastolic heart failure, reduced left and right ventricular function and arrhythmia (e.g. atrial fibrillation). Therefore treatment of sleep apnea might alleviate cardiac symptoms and improve cardiac function. Nevertheless, the exact role of long term treatment of sleep apnea in heart failure patients remains to be elucidated. |
5,781 | [Atrioventricular synchrony in patients with pacemaker with VDD mode pacing. A 14-year descriptive study]. | To analyze the performance of VDD mode pacing in patients with complete AV block with special attention on maintaining AV synchrony.</AbstractText>This is a descriptive, retrospective and observational study of a case series.</AbstractText>Intensive Medicine Department of a tertiary hospital.</AbstractText>All patients with VDD pacemakers implanted between 1994 and 2008.</AbstractText>The cause of the rhythm disorder, time of atrioventricular synchrony, cause of its loss, number of pacemaker replacement and reason, age when the first implant was performed, incidence of failure of atrial sensing and atrial fibrillation. We compared patients with atrial fibrillation with the rest who maintained normal atrial activity.</AbstractText>A total of 95 patients, 49 (51.6%) males and 46 (48.4%) female with mean age of 77.08+/-8.37 years, were analyzed. The most common symptom was dizziness and presyncope in 43 cases (45.3%), the most common rhythm disorder was the III AV block with wide QRS with 68 cases (71.6%). Average time of AV synchrony was maintained 73.01+/-4.2 months with no significant differences between different causes of synchrony loss. At the end of the study, 56 cases remained in AV synchrony (73.3%).</AbstractText>The preservation time of AV synchrony is high, the most important causes of loss being entry in atrial fibrillation and atrial infrasensing.</AbstractText>Copyright (c) 2009 Elsevier España, S.L. y SEMICYUC. All rights reserved.</CopyrightInformation> |
5,782 | Cardiac resynchronization therapy after atrioventricular node ablation for rapid atrial fibrillation in a heart transplant recipient with late allograft dysfunction. | We report the successful use of cardiac resynchronization therapy in an orthotopic heart transplant recipient with late graft dysfunction, severe heart failure, and atrial fibrillation requiring atrioventricular node ablation. This case highlights the potential role for cardiac resynchronization therapy in orthotopic heart transplant recipients with systolic dysfunction and heart failure, especially in the setting of forced right ventricular pacing. Despite potentially different mechanisms of left ventricular dysfunction, biventricular pacing should be considered for allograft recipients with conventional indications for cardiac resynchronization therapy. |
5,783 | Racial differences in atrial fibrillation prevalence and left atrial size. | Previous studies relying on clinical care data have suggested that atrial fibrillation is less common in African Americans than Caucasians, but the mechanism remains unknown. Clinical care may itself vary by race, potentially affecting the accuracy of atrial fibrillation ascertainment in studies relying on clinical data. We sought to examine racial differences in atrial fibrillation prevalence determined by protocol-driven electrocardiograms (ECGs) obtained in prospective cohort studies and to study racial differences in echocardiographic characteristics.</AbstractText>We pooled primary data from 3 cohort studies with atrial fibrillation adjudicated from study protocol ECGs and documentation of potentially important confounders: the Heart and Soul Study (n=1014), the Heart and Estrogen-Progestin Replacement Study (n=2673), and The Osteoporotic Fractures in Men Sleep Study (n=2911). Left atrial anatomic dimensions were compared among races from sinus rhythm echocardiograms in the Heart and Soul Study.</AbstractText>Of the 6611 participants, 268 (4%) had atrial fibrillation: Caucasians had the highest prevalence (5%), and African Americans had the lowest (1%; P<.001 for each compared with all other races). After adjustment for potential confounders, Caucasians had a 3.8-fold greater odds of having atrial fibrillation than African Americans (95% confidence interval, 1.6-8.8, P=.002). Although ventricular and atrial volumes and function were similar in Caucasians and African Americans, Caucasians had a 2 mm larger anterior-posterior left atrial diameter after adjusting for potential confounders (95% confidence interval, 1-3 mm, P<.001).</AbstractText>ECG confirmed atrial fibrillation is more common in Caucasians than in African Americans, which might be related to the larger left atrial diameter observed in Caucasians.</AbstractText> |
5,784 | Coronary blood flow and perfusion pressure during coronary angiography in patients with ongoing mechanical chest compression: a report on 6 cases. | Patients with pulseless electrical activity or refractory ventricular fibrillation have a very bad prognosis. Coronary angiography and angioplasty may be required to restore an effective circulation, but this must be performed whilst chest compressions are continued. The LUCAS chest compression device is suitable for this purpose. So far there are no reports on the effect of this device on coronary circulation in humans. We monitored the coronary perfusion pressure assessed invasively as the difference between the diastolic pressures at the coronary ostium and right atrium, and compared these pressures with coronary flow graded using the TIMI scale in 6 patients. In 4 out of 6 we found a satisfactory coronary artery perfusion pressure and TIMI grade 3 flow (normal) on coronary angiography. Two of these patients survived the first 24h. Two patients did not have a satisfactory perfusion pressure and adequate flow rate was not seen. |
5,785 | Neuromuscular and cardiac comorbidity determines survival in 140 patients with left ventricular hypertrabeculation/noncompaction. | The prognosis of patients with left ventricular hypertrabeculation/noncompaction (LVHT) is controversial. We assessed cardiologic and neurologic predictors for mortality in LVHT patients and how many received implantable cardioverters/defibrillators(ICD) or cardiac resynchronization devices (CRT).</AbstractText>Included were patients with LVHT diagnosed echocardiographically between June 1995 and May 2009. All patients underwent a baseline cardiologic examination, and were invited for a neurological investigation. During June 2009, the patients were contacted by telephone and their records were screened if they had received ICD or CRT. In 140 patients (29% females, mean age 53 ± 16, range 14-94 years) LVHT was diagnosed. The neurologic investigation, carried out in 76%, disclosed a neuromuscular disorder of definite (n = 22) or unknown (n = 68) etiology or was normal (n = 16). During a follow-up of 4.5 years the mortality was 5.7%/year. Causes of death were heart failure(n = 11), pneumonia (n = 6), sudden cardiac death (n = 3), malignancy (n = 3), pulmonary embolism(n = 2), sepsis (n = 2), stroke (n = 2), hepatic failure (n = 1) or unknown (n = 6). Sixteen patients received devices (ICD n = 4, CRT n = 3, ICD plus CRT n = 9). Predictors for mortality were increased age (p = 0.0307), neuromuscular disorder of definite or unknown etiology (p = 0.0063), exertional dyspnea (p =0.0018), edema (p = 0.0000), heart failure (p = 0.0002), ventricular ectopic beats (p = 0.0119), atrial fibrillation (p = 0.0000), low voltage (p = 0.0139), presence of one or more ECG abnormalities (p = 0.0420), left ventricular fractional shortening <25% (p = 0.0046), extension of LVHT (p = 0.0063) and LVHT affecting the lateral wall (p = 0.0110).</AbstractText>Mortality in LVHT is high and due to cardiac and neuromuscular comorbidity, why monitoring and therapy, including device therapy, should be improved.</AbstractText>Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
5,786 | Asynchronous contraction of the 2 ventricles caused by ventricular pacing after a Fontan-type operation in a patient with a biventricular heart. | We treated a 6-year-old boy who had polysplenia syndrome and tetralogy of Fallot with a small right ventricle (RV), an atrial septal defect, a hemiazygos connection, and bilateral superior vena cava. Because the RV was too small for a biventricular repair to be performed, the patient underwent a total cavopulmonary shunt operation although his heart was biventricular and a pacemaker (VVI) had been implanted for management of the sick sinus syndrome complicated by polysplenia syndrome. After the operation, marked asynchronous contraction was noted between the morphological right and left ventricles and was probably responsible for the low cardiac output noted in this patient. In order to clarify the significance of the asynchronous contraction, we determined the cause of the low cardiac output by studying the time course of the volume changes in the morphological right and left ventricles during a cardiac cycle by using angiograms. In addition, we studied the interventricular flow dynamics by using pulsed-Doppler echocardiography. After a Fontan-type operation is performed on patients with a biventricular heart, the 2 ventricles may not function in perfect coordination when they have to work as 1 unit. These patients are likely to develop cardiac dysfunction due to interventricular to-and-fro flow dynamics. Asynchronous contraction between the 2 ventricles caused by abnormal interventricular conduction impaired the cardiac performance in the present case. |
5,787 | Heart rate as an independent prognostic risk factor in patients with acute myocardial infarction undergoing primary percutaneous coronary intervention. | It has been shown that elevated heart rate identified patients with coronary artery disease and left ventricular dysfunction at increased risk of cardiovascular outcomes.</AbstractText>We sought to assess the prognostic impact of heart rate at presentation in patients with ST-elevation acute myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI).</AbstractText>We collected 6-month follow-up data in 2477 consecutive patients with STEMI treated by primary PCI. Patients with atrio-ventricular block (n=64) and atrial fibrillation (n=34) were excluded from the analysis. The association of baseline heart rate with cardiovascular outcomes was analysed using Cox proportional hazard models for groups with a heart rate of 80 beats per min (bpm) or greater (n=799) versus those with a heart rate between 60 and 79 bpm (n=1192) and those with a heart rate less than 60 bpm (n=388). The variables related to mortality were: age (hazard ratio (HR) 1.072, 95% confidence interval (CI) 1.052-1.092, p<0.0001), cardiogenic shock (HR 4.622, 95% CI 2.892-7.387, p<0.0001), previous myocardial infarction (HR 1.724, 95% CI 1.036-2.869, p=0.036), peak creatine-kinase value (HR 1.227, 95% CI 1.142-1.318, p<0.0001), heart rate 80 bpm or greater (HR 2.170, 95% CI 1.414-3.332, p=0.0001), and optimal PCI result (HR 0.126, 95% CI 0.065-0.244, p=0.0001). For every increase of 5 bpm, there were increases in mortality (HR 1.321, 95% CI 1.232-1.415, p=0.0001), but not in reinfarction or in coronary revascularization rates.</AbstractText>In patients with acute myocardial infarction undergoing primary PCI, elevated heart rate (80 bpm or greater) identifies those at increased risk of death. It is unknown whether heart rate reduction will result in improved outcome in this setting of patients.</AbstractText>Copyright (c) 2010 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
5,788 | Bentall procedure in ascending aortic aneurysm: hospital mortality. | Ascending aortic aneurysm disease (AAAD) shows a low frequency, heterogeneous behavior, high risk of rupture, dissection and mortality, making elective surgery necessary. Several procedures have been developed, and the Bentall technique is considered as the reference standard. The objective was to describe the hospital mortality of AAAD surgically treated using the Bentall procedure.</AbstractText>We carried out a descriptive study. Included were 23 patients with AAAD who were operated on between March 1, 2005 and September 30, 2008 at our hospital. Data were obtained from clinical files, and descriptive statistics were selected for analysis.</AbstractText>The study population was comprised of 23 patients with an average age of 46 years; 83% were males. Etiology was nonspecific degeneration of the middle layer with valve implication in 43%, bivalve aorta in 22%, Marfan syndrome, Turner's syndrome and poststenotic aneurysms each represented 9%, and Takayasu disease and ankylosing spondylitis 4% each. Associated heart disease was reported in six (26%) patients as follows: aortic coarctation (2), ischemic cardiopathy (1), atrial septal defect (1), severe mitral insufficiency (1) and subaortic membrane (1). Procedures carried out were Bentall surgery in 20 (87%) patients and aortoplasty with valve prosthesis in three (13%) patients. Complications reported were abnormal bleeding with mediastinal exploration (17%), nosocomial pneumonia (13%), arrhythmia (13%), and septic shock (9%). Mortality was reported in three (13%) patients due to septic shock and ventricular fibrillation.</AbstractText>Surgical mortality with the Bentall procedure is similar to published results by other specialized centers. Events related to the basic aortic pathology, surgical technique, aortic valve prosthesis and left ventricular dysfunction encourage longterm studies with follow-up.</AbstractText> |
5,789 | [The role of the accessory pathway radiofrequency catheter ablation in the secondary prevention of the malignant tachyarrhythmias in patients with Wolff-Parkinson-White syndrome]. | <AbstractText Label="BACKGROUND/AIM" NlmCategory="OBJECTIVE">The occurrence of atrial fibrillation (AF) in the presence of an accessory pathway (AP) that conducts rapidly is potentially lethal because the rapid ventricular response may lead to ventricular fibrillation (VF). The aim of the study was to determine long-term efficacy of AP catheter-ablation using radiofrequency (RF) current in secondary prevention of VF in WPW patients.</AbstractText>Study included a total of 192 symptomatic WPW patients who underwent RF catheter-ablation of AP in our institution from 1994 to 2007 and were available for clinical follow-up for more than 3 months after procedure.</AbstractText>Before ablation, VF was recorded in total of 27 patients (14.1%). In 14 of patients (51.9%) VF was the first clinical manifestation of WPW syndrome. A total of 35 VF episodes were identified in 27 patients. The occurence ofVF was preceded by physical activity or emotional stress in 17.1% of cases, by alcohol abuse in 2.9% and by inappropriate intravenous drug administration in 28.6%. In addition, no clear precipitating factor was identified in 40% of VF cases, while informations about activities preceding 11.4% of VF episodes were not available. The follow-up of 5.7 +/- 3.3 years was obtained in all of 27 VF patients. Of the 20 patients who underwent successful AP ablation, all were alive, without syncope or ventricular tachyarrhythmias during long-term follow-up. In 4 of 7 unsuccessfully treated patients, recurrence of supraventricular tachycardia and/or preexcited atrial fibrillation were recorded; one of these patients suddenly died of VF, 6 years after procedure.</AbstractText>In significant proportion of WPW patients, VF was the first clinical manifestation of WPW syndrome, often precipitated by physical activity, emotional stress or inappropriate drug administration. Successful elimination of AP by percutaneous RF catheter-ablation is highly effective in secondary prevention of life-threatening tachyarrhythmias in patients with ventricular preexcitation.</AbstractText> |
5,790 | National Registry on Cardiac Electrophysiology 2007 and 2008. | Clinical electrophysiology remains one of the most dynamic areas of cardiology, with continuing developments in equipping centers with more modern mapping and navigation systems. This has enabled an increase in the number and variety of interventions, resulting in significant improvements in results of therapeutic ablation of arrhythmias and prevention of sudden cardiac death. In this phase of transition towards implementation of a computerized national registry with nationwide data transmitted via the internet, publication of the registry in its previous form, although requiring more work, still seems justified, in order to appraise and disseminate qualitative and quantitative developments in this activity and enable comparisons with what is being done internationally, assess the centers' training capacity and inform national and European health authorities of the activities and real needs in this sector. The authors analyze the number and type of procedures performed during 2007 and 2008 based on a survey sent to centers performing diagnostic and interventional electrophysiology (16 centers in 2007 and 2008) and/or implanting cardioverter-defibrillators (ICDs) (19 centers in 2007 and 21 in 2008). Compared to 2006, one more center began interventional electrophysiology in 2007 and two centers began implanting ICDs in 2008. In the years under review, 2060 electrophysiological studies were performed in 2007 and 2007 were performed in 2008, of which 74 and 79.5% respectively were followed by therapeutic ablation, making totals of 1523 and 1596 ablations (increases of 10.7 and 4.6% from previous years). Atrioventricular nodal reentrant tachycardia was the main indication for ablation (28.4 and 28.7%), followed by accessory pathways (26.8 and 25.4%), atrial flutter (20.8 and 19.7%), atrial fibrillation (13.9 and 14.6%), ventricular tachycardia (4.7 and 5.1%), atrial tachycardia (2.8 and 2.6%) and atrioventricular junction ablation (2.7 and 3.9%). Regarding ICDs, a total of 890 devices were implanted in 2007 and 1040 devices in 2008, of which 63 and 75 respectively were battery replacements and 827 and 965 were first implantations, with the following distribution: single chamber--53.7% in 2007 and 61.4% in 2008; dual chamber--13.8 and 8.4% respectively in 2007 and 2008; resynchronization systems with ICD--32.5% in 2007 and 30.2% in 2008. The figures for first implantations show growth of 18.5% between 2006 and 2007 and 14.3% between 2007 and 2008. First implantations increased from 67.4 devices per million population in 2006 to 82.7 in 2007 and 96.5 in 2008. |
5,791 | Drug-induced QT prolongation and sudden death. | Prolongation of the QT interval can predispose to a potentially fatal polymorphic ventricular tachycardia called torsades de pointes (TdP). Although usually self-limited, TdP may degenerate into ventricular fibrillation and cause sudden death. Some medications that cause QT prolongation and possible TdP are commonly used in general practice. This paper presents a case of sudden death that is likely from drug-induced TdP. It reviews the mechanisms, risk factors, offending agents, and management of drug-induced torsades de pointes. |
5,792 | [Analysis of response reports of an in-hospital emergency team : Three years experience at a maximum medical care hospital]. | In-hospital emergencies can lead to unexpected admission to the ICU, cardiac arrest or even death. Therefore, hospitals have to implement an adequate in-hospital emergency management. The results of the deployment of the in-hospital emergency team of a hospital providing maximum medical care will be presented.</AbstractText>In 2003 the Westpfalz-Klinikum, Kaiserslautern introduced a central emergency team. The data of the emergency teams on alarm calls and the patient records from 2004 to 2007 were evaluated.</AbstractText>There were 241 alarm calls (9 alarm calls/100 beds and year). The mean age of the patients was 67 years and 56% were male. In 79% of all alarm calls the vital functions were compromised and in 37% cardiac arrest had occurred. When the emergency team arrived all cardiac arrest patients had received basic life support, however, no early defibrillation had been applied. On arrival of the emergency team 41% of the patients could be left on-site after emergency treatment, 40% had to be admitted to an intensive care or intermediate care unit and 21% died or were already dead (5 patients). In 27% of all cardiac arrests ventricular fibrillation/pulseless ventricular tachycardia was the first detected sign. Restoration of spontaneous circulation could be established in 53% and 20% of all resuscitated patients could be discharged. Respiratory emergencies (21%) and altered states of consciousness (20%) were other leading causes for calling the emergency team.</AbstractText>The high proportion of patients in a life-threatening condition and cardiac arrests indicates the necessity for closer patient monitoring, more intensive emergency training including early defibrillation and continuing education of hospital staff in the prevention and early detection of emergencies, in addition to the provision of an emergency team.</AbstractText> |
5,793 | Electroanatomic study of the left atrial insertion of an epicardial accessory pathway integrating the coronary sinus. | Endocardial electro-anatomic reconstruction of the left atrium and activation mapping defined a very large atrial accessory pathway insertion with a previously failed ablation attempt. Radiofrequency application inside the coronary sinus (CS), at a site with a sharp electrogram bridging atrial and ventricular electrograms abolished pathway conduction. The myocardium in the venous branches of the CS appeared to be responsible for this extraordinary atrial insertion area. |
5,794 | Elevated oxidative stress is associated with ventricular fibrillation episodes in patients with Brugada-type electrocardiogram without SCN5A mutation. | Brugada syndrome is a disease known to cause ventricular fibrillation with a structurally normal heart and is linked to SCN5A gene mutation. However, the mechanism by which ventricular fibrillation develops in cases of Brugada-type electrocardiogram without SCN5A mutation has remained unclear. Recently, oxidative stress has been implicated in the pathophysiology of cardiac arrhythmia. We also investigated oxidative stress levels in the myocardia of patients with Brugada-type electrocardiogram.</AbstractText>Endomyocardial biopsy samples were obtained from 68 patients with Brugada-type electrocardiogram (66 males and two females). We performed histological and immunohistochemical analyses for CD45, CD68, and 4-hydroxy-2-nonenal-modified protein, which is a major lipid peroxidation product.</AbstractText>SCN5A mutation was detected in 14 patients. Ventricular fibrillation was documented in three patients with SCN5A mutation and in 11 without SCN5A mutation. In patients with SCN5A mutation, 4-hydroxy-2-nonenal-modified protein-positive area was not significantly different between the documented ventricular fibrillation (VF) group (VF+ group) and the group without documented VF (VF- group). However, in patients without SCN5A, the area was significantly larger in the VF+ group than that in the VF- group (P<.05). All other parameters (fibrosis area, CD45, and CD68) were not different between the VF+ and VF- group in both SCN5A+ and SCN5A- patients.</AbstractText>Oxidative stress is elevated in the myocardium of patients with Brugada-type electrocardiogram who have VF episodes and do not have SCN5A gene mutations. Oxidative stress may be associated with the occurrence of VF in patients with Brugada-type electrocardiogram without SCN5A mutation.</AbstractText>Copyright © 2011 Elsevier Inc. All rights reserved.</CopyrightInformation> |
5,795 | Impaired tissue clearance of verapamil in rat cardiac hypertrophy results in transcriptional repression of ion channels. | Heart hypertrophy is a common cardiac complication of sustained arterial hypertension and is accompanied by an increased incidence of supraventricular tachyarrhythmia, such as atrial fibrillation and atrial flutter. Verapamil, a phenyalkylamine, belongs to the group of calcium channel antagonists (class IV antiarrhythmic drugs) and is frequently used for the management of supraventricular tachycardia and for ventricular rate control in atrial fibrillation and atrial flutter. Verapamil heart tissue and plasma levels after intraperitoneal dosing of spontaneously hypertensive and normotensive rats were investigated. Transcript expression of various ion channels, ion transporters, calcium handling, and cytoskeletal proteins by reverse transcriptase-polymerase chain reaction (RT-PCR) were further investigated. There was no difference in plasma pharmacokinetics when hypertensive and normotensive animals were compared. Strikingly, the tissue clearance of verapamil was highly significantly impaired in heart tissue of hypertensive animals. Gene expression analysis showed the repression of many cardiac-specific genes in spontaneously hypertensive but not in normotensive rats, therefore providing evidence for different modes of action in healthy and hypertrophic hearts. Verapamil heart tissue levels differed dramatically between normotensive and hypertensive rats and resulted in repression of many cardiac ion channels, ion transporters, and calcium handling proteins. A disturbed ion homeostasis induced by critical tissue levels of verapamil is therefore proposed as a molecular rational for its pro-arrhythmogenic activity. The observed changes can be a significant determinant of spatial electrophysiological heterogeneity, thereby contributing to increased conductance disturbance as observed with some patients. |
5,796 | Fever-induced precordial ST-segment elevation in a young man. | Brugada syndrome is a rare condition characterized by ST-segment elevation in the right precordial leads. Fever can induce Brugada-like electrocardiographic (ECG) changes. We reported on a 26-year-old male patient with fever and ST-segment elevation in the right precordial leads. Serial cardiac markers were normal and transthoracic echocardiography showed normal wall motion and no evidence for pericardial effusion. Brugada-like ECG changes disappeared after fever resolved. Since the patient had never experienced any arrhythmic symptom, syncope, or spontaneous type 1 ECG, electrophysiological study was not performed and he was not referred for defibrillator implantation. The patient was discharged with strong recommendations to avoid certain medications responsible for Brugada-like ECG changes and to receive urgent treatment for fever. He was asymptomatic during a year follow-up. Emphasis is placed on this particularly rare, but important condition, as it may easily be misdiagnosed and fever may even precipitate ventricular fibrillation. |
5,797 | [Clinical analysis of precaution against atrial fibrillation following cardiac surgery: landiolol or amiodarone?]. | Atrial fibrillation following cardiac surgery remains as a most common complication. Tachycardia with atrial fibrillation just after the operation could lead to cardiac deterioration. Although we have to control tachycardia, we often have great difficulties in managing these arrhythmias. Many reports have showed landiolol, ultra short-acting beta1 blocker, and amiodarone were effective against postoperative atrial fibrillation. However there has been no report on comparison between these 2 drugs. As excessively sympathetic activity might cause atrial fibrillation, landiolol was introduced into our therapy concomitant with the sedative. Our investigation confirmed that both landiolol and amiodarone were effective in preventing atrial fibrillation, and that the timing of transition from intravenous administration to oral intake was acceptable. When landiolol was administered, enough attention should be paid to the patients whose left ventricular function was low. The patients in whom atrial fibrillation occurred under landiolol therapy showed tendency of lower heart rate in comparison with the patients under amiodarone therapy. |
5,798 | Cardiac Rac1 overexpression in mice creates a substrate for atrial arrhythmias characterized by structural remodelling. | The small GTPase Rac1 seems to play a role in the pathogenesis of atrial fibrillation (AF). The aim of the present study was to characterize the effects of Rac1 overexpression on atrial electrophysiology.</AbstractText>In mice with cardiac overexpression of constitutively active Rac1 (RacET), statin-treated RacET, and wild-type controls (age 6 months), conduction in the right and left atrium (RA and LA) was mapped epicardially. The atrial effective refractory period (AERP) was determined and inducibility of atrial arrhythmias was tested. Action potentials were recorded in isolated cells. Left ventricular function was measured by pressure-volume analysis. Five of 11 RacET hearts showed spontaneous or inducible atrial tachyarrhythmias vs. 0 of 9 controls (P < 0.05). In RacET, the P-wave duration was significantly longer (26.8 +/- 2.1 vs. 16.7 +/- 1.1 ms, P = 0.001) as was total atrial activation time (RA: 13.6 +/- 4.4 vs. 3.2 +/- 0.5 ms; LA: 7.1 +/- 1.2 vs. 2.2 +/- 0.3 ms, P < 0.01). Prolonged local conduction times occurred more often in RacET (RA: 24.4 +/- 3.8 vs. 2.7 +/- 2.1%; LA: 19.1 +/- 6.3 vs. 1.2 +/- 0.7%, P < 0.01). The AERP and action potential duration did not differ significantly between both groups. RacET demonstrated significant atrial fibrosis but only moderate systolic heart failure. RacET and statin-treated RacET were not significantly different regarding atrial electrophysiology.</AbstractText>The substrate for atrial arrhythmias in mice with Rac1 overexpression is characterized by conduction disturbances and atrial fibrosis. Electrical remodelling (i.e. a shortening of AERP) does not play a role. Statin treatment cannot prevent the structural and electrophysiological effects of pronounced Rac1 overexpression in this model.</AbstractText> |
5,799 | Prevalence and clinical characteristics of nondilated cardiomyopathy and the effect of atrial fibrillation. | The treatment of patients with chronic heart failure and those with asymptomatic left ventricular (LV) dysfunction has focused primarily on patients with LV enlargement and a low ejection fraction (EF). Little attention has been paid to those with a normal chamber size and a low EF. We sought to examine the LV geometry and clinical characteristics in such patients with nondilated cardiomyopathy. Of 3,350 transthoracic echocardiograms performed during a 6-month period, 696 showed an EF of < or =0.45. The patients with an end-diastolic diameter of >56 mm, regional wall motion abnormalities, or valvular disease were excluded. Of the 696 patients, 98 met these criteria, and their medical records were reviewed. The average age was 71 +/- 14 years, and 56% were men. Common co-morbidities included hypertension in 52% and atrial fibrillation (AF) in 43%. Only 22% had disabling cardiac symptoms (functional class III or greater). The average end-diastolic dimension was 49 +/- 5 mm, and the EF was 34 +/- 8%. LV hypertrophic remodeling was present in 53%. A second echocardiogram (422 +/- 177 days after the baseline study) was available for 54 patients. The chamber size was unchanged, but the EF had increased from 33 +/- 8% to 40 +/- 14% (p <0.01). The improvement in EF was seen in the group with AF (33 +/- 6% to 44 +/- 15%, p <0.01) but not in those with normal sinus rhythm (33 +/- 9% to 37 +/- 12%, p = NS). In conclusion, 14% of patients with an EF of < or =0.45 had nondilated cardiomyopathy, often with LV hypertrophic remodeling and/or AF. An improvement in LV function can be expected in many patients with nondilated cardiomyopathy, particularly those with AF. |
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