Effects of myocardial fiber orientation on the electrical induction of ventricular fibrillation

Myocardial fiber orientation influences the series of activation, repolarization, gradient filed distribution and the stimulation threshold during electrical induction of ventricular fibrillation (VF). Myocardial fiber orientation is essential for generation and maintenance of reentrant arrhythmia. Computerized mapping analysis of patterns of activation, as a result of application of stimulus, using 56 closely spaced epicardial bipolar electrodes, is carried out on six open-chest dogs. The results suggest the important contribution made by myocardial fiber orientation in determining the patterns of activation during the electrical induction of VF.