Considerations of current methods for drug selection in treating malignant ventricular arrhythmias

The current burgeoning interest in antiarrhythmic drugs derives in large measure from a growing concern with the enormous problem of sudden cardiac death. Until the latter half of the twentieth century, beyond a nodding acknowledgment of its massive prevalence, this syndrome received but scant attention from the medical profession. In the early 1960s a number of insights changed perceptions as well as practice. These related to 4 postulates: (1) sudden cardiac death, in the majority of victims, was due to ventricular tachyarrhythmias either initiated by or culminating rapidly in ventricular fibrillation; (2) the lethal arrhythmia was not the consequence of irreversible pathomorphologic impairment of the contractile apparatus, but rather the expression of an electrophysiologic derangement; (3) the triggering of ventricular fibrillation was the result of an electrical accident both reversible as well as preventable; (4) the potential victim was identifiable either by the presence of certain grades of ventricular ectopic activity or by exposure of repetitive ectopic activity or by exposure of repetitive ventricular arrhythmias by electrophysiologic techniques. The innovations that have led to these insights and their consequences have been numerous and continuous. Among these are direct current defibrillation, cardioversion, coronary care units, bystander-initiated cardiopulmonary resuscitation, ambulatory electrocardiographic monitoring and exercise stress testing for exposing ventricular arrhythmias, electrophysiologic provocative testing and mapping techniques, overdrive programmable pacemakers as well as implantable defibrillators and cardioverters, and surgical, electrical and laser techniques for ablating the nidus or interrupting the pathways of the arrhythmias.