five cases are reported in which verapamil was used to terminate a cycle of supraventricular tachycardia-mediated recurrent ventricular fibrillation that could not be suppressed by conventional antidysrhythmics such as lidocaine , procainamide , and bretylium , proposed mechanisms of verapamil 's beneficial effect in this usually fatal situation include ( 1 ) a reduction in oxygen consumption related to the reduction in heart rate , thereby raising the ventricular fibrillation threshold ;
C0039240
supraventricular tachycardia
C0033216
procainamide