Distribution of myocardial blood flow before and after coronary artery ligation in the baboon. Relation to early ventricular fibrillation

Abstract

The distribution of coronary blood flow before and for 60 min after coronary artery ligation was studied in the baboon by the distribution of radioactively-labelled microspheres. Perfusion was uniform in epicardial, middle, and endocardial sections of four regions from normal left ventricular myocardium. Within 10 min of coronary artery ligation the flow in the central area of the infarcting tissue fell to 5% of the control value. Three-quarters of the baboons developed ventricular fibrillation within 60 min of coronary artery ligation. In baboons that developed ventricular fibrillation there was an increase in blood supply to the border zone surrounding the infarct, compared with baboons that survived for 60 min. The increased gradient of flow between infarct and border tissue in baboons that developed fibrillation may contribute to the establishment of biochemical gradients which in turn may be causally related to the occurrence of ventricular fibrillation.