A model of anatomically opposed ischaemia

This study aims to gain an understanding of anatomically opposed ischaemia, or “ischaemic ST-segment counterpoise”, by determining and examining epicardial potential distributions resulting from two regions of subendocardial ischaemia during the ST-segment. The finite volume method is used to solve the passive bidomain equation in an isolated semi-ellipsoidal model of the left ventricle. A model with one moderately sized ischaemic region is used as a base case. Subsequently, regions of ischaemia of varying size are placed in various positions in the posterior and anterior, inferior or left lateral regions of the ventricular wall. Simulations show that having two regions of ischaemia produces epicardial potential distributions that are different from those with one ischaemic region. With two ischaemic regions of markedly different size within the left ventricular wall, the larger region dominates the resulting epicardial potential distribution, making the smaller region difficult to observe. Two ischaemic regions of similar size are identifiable on the epicardial potential distribution.