Functional consequences of GAP junction remodeling in the epicardial border zone of canine infarcted hearts

Abstract

Reentrant circuits causing tachycardia (VT) in the canine infarcted heart have a figure-8 activation pattern with a central (CCP) and an outer pathway (OP). In the OP, Cx43 is located at the intercalated disks but side-to-side gap junction conductance (Gj) is reduced by 90% (end-to-end Gj is normal). End-to-end and side-to-side Gj in the CCP are both normal but Cx43 redistributes along the lateral membrane. Remodeling of Na channel causes a reduction of INa in both OP and CCP with a larger reduction in the CCP.