Effect of carbocromen induced coronary vasodilatation on myocardial metabolism in coronary artery disease.

Myocardial metabolism was studied during coronary vasodilatation by carbocromen during atrial pacing in patients with coronary arteriosclerotic disease. Coronary sinus flow was measured by the continuous infusion thermodilution technique. Carbocromen increased myocardial flow by the same amount at rest and during pacing-induced tachycardia. The administration of carbocromen did not interfere with myocardial oxygen consumption, free fatty acid (FFA) uptake, pulmonary or systemic hemodynamics. Atrial pacing above the anginal threshold increased lactate and hypoxanthine excretion to the coronary sinus, but to a greater extent during carbocromen treatment. Thus, carbocromen is a specific coronary vasodilator acting independently of pacing induced vasodilatation. Metabolic data indicate a small but unfavourable effect on ischemic metabolism which might be due to a "coronary steal".