Electrophysiologic studies of the ventricle.

Electrophysiologic assessment of ventricular tachyarrhythmias involves the application of paced ectopic beats at the discretion of the cardiologist and not by chance. Because this approach reproducibly induces the sort of symptomatic arrhythmias that are the major cause of death in our country, the procedure has attracted widespread interest. This methodology has accomplished two important alterations in the orientation of physicians to ventricular arrhythmias and sudden death. First, it has turned our focus away from innocent events such as ectopic beats and directed our attention to the architectural and electrophysiologic abnormalities that are the structural substrate for tachyarrhythmias. Second, it has taught us that malignant arrhythmias and sudden death can be treated empirically by repeatedly inducing VT under controlled conditions until a treatment is found. The physiologic and pharmacologic insight obtained with these early experiences will hopefully enable us to treat patients without the need for producing potentially lethal arrhythmias.