Mechanisms of arrhythmias and heart fibrillation in myocardial ischemia and the possible role of Purkinje cells in their origin

: Morphological, metabolic and functional features of the heart subendocardial areas under normal conditions and at early periods of myocardial ischemia are considered in this review. It is suggested that the arrhythmias and fibrillation developing at early stages of ischemia arise in the subendocardium. The initiators of this process may be altered Purkinje's cells as precisely these cells in ischemia acquire certain characteristics necessary for the development of ectopic foci, namely: cells remaining viable should have a lowered threshold of excitability and a capacity for automatism. Further study of Purkinje's cells is particularly important for understanding of causes and prevention of a high lethality at acute phase of the myocardial infarction.