Effect of nifedipine on exercise-induced left ventricular dysfunction and myocardial hypoperfusion in stable angina.

To assess the effects of nifedipine on left ventricular function and regional myocardial perfusion, exercise radionuclide ventriculography was performed in 15 men (median age 59 years) and exercise thallium-201 scintigraphy was done in 11 of them, before and 90 minutes after the oral administration of 20 mg of nifedipine. All patients had stable angina and angiographically proved coronary artery disease without evidence of spasm. Exercise tolerance after administration of nifedipine increased from 343 +/- 42 seconds to 471 +/- 50 seconds (p less than 0.01), whereas the peak exercise double product remained essentially unchanged (difference not significant). Ejection fraction improved significantly at rest (from 49 +/- 3.6% to 52 +/- 3.3%, p less than 0.05) and at peak exercise (42 +/0 3.3% to 47 +/- 3.7%, p less than 0.05). Nifedipine also resulted in an improved segmental wall motion score (4.3 +/- 2.3 to 3.0 +/- 2.3, p less than 0.05; 0 = normal and 4 = worst degree of dysfunction). The ejection fraction increased by more than 5% in one third of the patients at rest, and in more than half of the patients at peak exercise. Improved exercise myocardial perfusion occurred in 5 of 11 patients (45%) and in 7 of 28 segments (25%) with reversible hypoperfusion. Thus, nifedipine produces significant improvement in global and regional left ventricular function in patients with coronary artery disease and stable angina. This may be accounted for, at least in part, by improvement in myocardial perfusion.