Influences of anisotropic tissue structure on reentrant circuits in the epicardial border zone of subacute canine infarcts.

摘要: Excitation in the epicardial border zone of 3-5-day-old canine infarcts was mapped with an array 192 bipolar electrodes during sustained ventricular tachycardia. Reentrant circuits were found which activation occurred around long lines apparent conduction block based on criterion that excitation opposite sides marked disparity time. When functional (i.e., only tachycardia and not sinus rhythm or pacing) they oriented parallel to axis muscle fiber bundles. Isochrones distal them because widely separate sites within these isochrones activated nearly simultaneously. This suggested but also slowly across them. slow transverse myocardial fibers therefore might result anisotropic tissue properties. To test this hypothesis, stimulated through its margin at center recording array. Activation regions where slow, whereas it rapid fibers' orientation. During electrograms along had durations fractionated, a characteristic can from axis. Therefore, we propose orientation bundles is important cause sufficiently permit occurrence reentry.