Effect of an antianginal drug, perhexiline, on myocardial oxygen consumption in anesthetized open-chest dogs compared with verapamil and glyceryl trinitrate.

A pharmacological study on myocardial oxygen consumption was carried out in open-chest dogs using an arterio-venous oxygen difference analyzer. The continuous monitoring of the oxygen difference showed that the peak changes in coronary blood flow did not coincide with the greatest change in myocardial oxygen consumption. Perhexiline, 0.3-3 mg/kg intravenously, increased coronary blood flow and decreased myocardial oxygen consumption, dose-dependently. Perhexiline decreased aortic and systemic blood pressures and left ventricular work except for lower doses of perhexiline which slightly increased cardiac output and ventricular work. Over-all mechanical efficiency of the left ventricle was increased with perhexiline, while the efficiency was decreased around the peak effect of larger doses of the drug on systemic blood pressure and coronary artery. Verapamil, 0.03-0.3 mg/kg, showed essentially the same effects as perhexiline with ten-fold potency superior to perhexiline. Glyceryl trinitrate showed inconsistent effects on coronary flow and myocardial oxygen consumption, and it decreased cardiac work and mechanical efficiency of the left ventricle.