Abstract
An isolated ventricular endocardial preparation removed from canine hearts one to two days after coronary artery occlusion and superfused in vitro is described. The alteration in electrophysiological characteristics of subendocardial Purkinje fibers surviving in infarcted regions and the relationship of these changes to the generation of ventricular arrhythmias is discussed. The advantages of such preparations for assessing the mechanism of action of antiarrhythmic drugs in post-infarction ventricular arrhythmias is discussed.