Comparison of acute hemodynamic effects of nitroglycerin versus diltiazem and combined acute effects of both drugs in angina pectoris.

Fifteen patients with exertional angina underwent hemodynamic monitoring and measurement of cardiac output during a control treadmill exercise test. They were then randomized to receive sustained-release nitroglycerin, 13 mg (group I) or placebo (group II). Repeat exercise testing revealed that in group I, both maximal oxygen consumption and cardiac output increased significantly. In group II neither maximal oxygen consumption nor cardiac output increased significantly. All patients then received diltiazem, 60 mg, and repeat testing was carried out 1 hour later. In group I maximal oxygen consumption and cardiac output were higher than control, but were no higher than after nitroglycerin. In group II, maximal oxygen consumption increased significantly, but the increase in cardiac output was not significant. Thus, sustained-release nitroglycerin, 13 mg, or diltiazem, 60 mg, both improve exercise performance, but the combination does not improve exercise performance to an extent greater than either drug alone.