tokens: Bepridil at a dose of 5 X 10 ( - 6 ) M , induced a concomitant reduction in AP amplitude ( falling from 71 + / - 8 mV to 47 + / - 6 mV ) , maximum systolic depolarization velocity ( phase 0 ) which fell from 1 . 85 + / - 0 . 35 V / s to 0 . 84 + / - 0 . 28 V / s , together with maximum diastolic depolarization velocity ( phase 4 ) which fell from 38 + / - 3 mV / s to 24 + / - 5 mV / s .