MYOCYTE INTERCONNECTIONS AT GAP-JUNCTIONS AND THE DEVELOPMENT OF ANATOMIC SUBSTRATES OF VENTRICULAR ARRHYTHMIAS

Spontaneous ventricular tachyarrhythmias causing sudden death occur of ten in patients with healed myocardial infarcts. A reentrant mechanism has been implicated that depends, in part, on slow heterogeneous cond uction and block in critical regions that have been mapped to the bord ers of the healed infarcts. The electrophysiological derangements resp onsible for initiation and maintenance of the reentrant tachycardia ci rcuit appear to be attributable largely to abnormalities in current tr ansfer between myocytes in the fibrotic border zone region. This revie w summarizes recent advances in understanding the role of gap junction s in intercellular electrical coupling in the normal heart and mechani sms of altered junctional coupling in the pathogenesis of reentrant ve ntricular tachycardia.