Hemodynamic factors associated with the production of pain in angina pectoris.

18 patients with uncomplicated angina pectoris were studied to ascertain the relative significance of individual hemodynamic factors in the production of angina pectoris. Each hemodynamic determinant of myocardial oxygen consumption (heart rate, systemic arterial pressure, LVEDP, and LV dp/dt max) were either altered or controlled as discretely as possible with the use of right atrial pacing, propranolol, phentolamine and ouabain, and the effects of these changes were observed on the onset and total duration of pain. Only heart rate correlated closely with the precipitation of angina. The systemic arterial pressure, LVEDP and LV dp/dt max did not correlate with the production and abolition of angina pectoris. The results indicate that drugs acting only against the effect of sympathetic stimulation of the sinus node would be a major advantage in the treatment of patients with angina pectoris. The unexpected finding that phentolamine did not ameliorate pain in patients with angina pectoris casts doubts as to whether nitroglycerine relieves anginal pain by lowering the systemic arterial pressure.