Effects of ouabain on the left ventricular response to atrial pacing in patients with angina pectoris

The hemodynamic response of the left ventricle to rapid atrial pacing was evaluated in 11 patients with angiographically proved coronary arterial disease. A depression in the pumping performance of the left ventricle (defined here as a rise in left ventricular end-diastolic pressure accompanied by a fall in stroke work) was found in 2 of 10 patients during pacing and in 3 of 6 patients 1 minute after pacing. In the control state, ouabain increased the performance of the left ventricle as a muscle, as evidenced by a rise in dp/dt and a fall in end-diastolic pressure in 7 of 11 patients, but the glycoside did not affect significantly the pumping performance of the left ventricle. During pacing ouabain did not alter significantly any of the hemodynamic indexes measured. Among the 9 patients who experienced angina with pacing, the heart rate and the left ventricular pressurerate product at which pain occurred were not changed by the administration of ouabain. Thus, atrial pacing causes a decrease in left ventricular performance in some but not all patients with coronary arterial disease, and although ouabain improves some indexes of left ventricular function during the control state, the drug does not prevent or delay the onset of angina.