Regional metabolic changes in the myocardium following coronary artery ligation in dogs

Abstract

Metabolic and hemodynamic changes were studied in dogs before and at 5 minute intervals following ligation of the anterior descending coronary artery. By placing catheters in the arterial (A), main coronary sinus (CS), and great cardiac vein (CV) positions, it was possible to collect simultaneous samples from the three sites and analyze the effluent for pH, Po 2, potassium, glucose, pyruvate, and lactate. Following coronary ligation, there was a significant decrease in pH and glucose and an increase in lactate and potassium in the CV samples. The Po 2 value did not change significantly. The CS drainage exhibited minor changes and only when the changes in the CV samples were marked. The hemodynamic changes included a slight fall in blood pressure, an increase in isovolumetric contraction period, and an increase in left ventricular end-diastolic pressure following coronary ligation. The results and the technique are discussed with emphasis on metabolic alterations in regional venous drainage following coronary artery ligation.