Anatomic-electrophysiologic basis for the surgical treatment of refractory ischemic ventricular tachycardia

Abstract

Recently developed surgical procedures for the treatment of refractory ischemic ventricular tachycardia have significantly improved the prognosis of patients experiencing these life-threatening arrhythmias. Ventricular tachyarrhythmias associated with ischemic heart disease most commonly originate from the ischemic border zone of myocardial infarctions, where the non-uniformity of tissue injury is most prominent. The inhomogeneity in tissue injury results in desynchronization of electrical wavefront propagation through the ischemic myocardium, thus providing the milieu necessary for the development of micro-reentrant circuits that give rise to the ventricular tachyarrhythmias. Preoperative and intraoperative electrophysiologic mapping techniques are capable of characterizing and localizing such arrhythmogenic myocardium sufficiently to direct the surgeon in his operative approach to the treatment of the arrhythmia. Surgical options include the encircling endocardial ventriculotomy, the endocardial resection procedure, endocardial cryoablation, and combinations or modifications of these three basic procedures. The use of these procedures has made the previously employed indirect surgical procedures obsolete for the treatment of refractory ischemic ventricular tachyarrhythmias.