Cardiohemodynamic Effects of SK&F 24260, D 600, Diltiazem, Dilazep, and Trimetazidine in the Dog

The cardiohemodynamic effects of a hypotensive agent, SK&F 24260, and coronary vasodilators, diltiazem, dilazep, and trimetazidine, and D 600 were studied in anesthetized open-chest dogs. The systemic blood pressure, cardiac output (pulmonary arterial flow), venous return (sum of the inferior and superior caval flow), right atrial pressure and heart rate were measured. All 5 drugs decreased the systemic blood pressure and heart rate and increased the right atrial pressure. The venous return and the cardiac output were reduced by higher doses of all the 5 drugs. However, SK&F 24260 in a wide range of doses greatly and diltiazem slightly but clearly increased the venous return and cardiac output. It appears that SK&F 24260 affects predominantly blood vessels whereas the other drugs affect rather the heart to produce a negative inotropic action.