Surgical therapy for ventricular tachyarrhythmias

Abstract

Recurrent sustained ventricular tachyarrhythmias unresponsive to medical therapy are associated with a one year mortality of 70 to 85 per cent. Patients who are susceptible to these re-entrant arrhythmias usually have a history of previous myocardial infarction or chronic myocardial ischemic disease. More specifically, these patients demonstrate both anatomic and electrophysiologic derangements. Experimental work suggests that regions of non-uniform damage render the ventricle most susceptible to ventricular tachyarrhythmias, and even relatively large areas of homogeneous myocardial ischemic damage may not display the same susceptibility to these arrhythmias. Surgical techniques are being devised to treat patients with ventricular tachyarrhythmias refractory to medical management. These have provided control of arrhythmias in patients whose disease was previously resistant to all medical treatment. The evolving surgical therapies presently employed share either of two physiopathologic consequences which render them successful: the homogeneous ablation of previous heterogeneous myocardial ischemic damage or the delimiting of an arrhythmogenic focus by excluding conduction to surrounding myocardium. Finally, antitachycardia and defibrillating devices have also been developed to facilitate the management of patients not controlled satisfactorily with either conventional or investigative drugs. The surgeon will need to be familiar with these devices as well.