Effect of practolol on exercise tolerance in patients with angina pectoris

Clinical and hemodynamic effects of combined propranolol and nifedipine therapy versus propranolol alone in patients with angina pectoris

To determine the comparative effectiveness and hemodynamic effects of long-term oral treatment with propranolol alone and combined with nifedipine in patients with stable angina pectoris, 20 patients with coronary disease were studied by equilibrium radionuclide ventriculography. Measurements were performed at rest and during supine bicycle exercise before treatment, after 4 weeks on propranolol, 1 hour after institution of combined propranolol and nifedipine treatment, and after 4 weeks on the combined treatment. The reduction in exercise rate-pressure product induced by the combination (17.2 +/- 2.6 X 10(3)) was significantly greater (p less than 0.001) than that attained by propranolol alone (19.3 +/- 2.8 X 10(3)). In patients at rest, neither propranolol nor the combined therapy altered global left ventricular (LV) ejection fraction (EF). Without drugs and on propranolol, exercise EF decreased significantly. On the combined therapy there was a significant improvement in exercise EF compared both with rest values (p less than 0.01) and with exercise EF on propranolol (p less than 0.001). Exercise tolerance, expressed as total work load, significantly increased on propranolol and further increased on combined therapy. Thus the combined propranolol/nifedipine therapy in patients with stable angina proved to be hemodynamically superior to therapy with propranolol alone and safe even in patients with moderately depressed LV function.

Combined acebutolol/nifedipine therapy in patients with chronic coronary artery disease: additional improvement of ischemia-induced left ventricular dysfunction

To assess acute hemodynamic effects of combined oral nifedipine (10 mg) and acebutolol (100 mg), 21 patients with angiographically documented coronary artery disease and stable angina pectoris were studied (three groups of seven randomized patients). Simultaneous hemodynamic and equilibrium radionuclide ejection fraction measurements were performed at rest and during exercise before treatment, 1 hour after administration of nifedipine, acebutolol or a combination of the two and again 1 hour after combined nifedipine and acebutolol. At the same exercise level achieved without drugs, angina, subjectively scored by the patients, decreased significantly after nifedipine, acebutolol and a combination of the two in association with a significant improvement in left ventricular ejection fraction (p less than 0.01). There was an additive effect of both drugs on heart rate, systolic blood pressure and therefore the double product (p less than 0.01 each). The negative effects of acute beta receptor blockade on cardiac index, resting ejection fraction and total peripheral resistance were balanced by the vasodilatory action of nifedipine. In patients with borderline heart failure no untoward effects were seen after combined therapy. Thus, acute combined acebutolol/nifedipine therapy in patients with stable angina proved to be hemodynamically superior to therapy with either drug alone and safe even in patients with moderately depressed left ventricular function. This finding provides a basis for appropriately designed long-term studies.

Verapamil in stable effort angina: effects on left ventricular function evaluated with exercise radionuclide ventriculography

A double blind placebo-controlled study was performed in 12 patients with stable angina pectoris to evaluate the effects of oral verapamil (320 mg/day) on left ventricular function, as measured at rest and during exercise with gated equilibrium radionuclide ventriculography. On verapamil, patients had a lower heart rate-blood pressure product at each work load than with placebo. Anginal threshold increased by 28 +/- 19 watts (p less than 0.005), and maximal exercise capacity increased by 20 +/- 14 watts (p less than 0.001) with verapamil, but the rate-pressure product at the onset of angina and at maximal exercise was unchanged. Left ventricular ejection fraction at rest during verapamil therapy was the same as with placebo therapy. On exercise during placebo therapy, the ejection fraction decreased from 40 +/- 9 to 35 +/- 11 percent (p less than 0.025) because end-systolic volume increased disproportionately compared with end-diastolic volume. On exercise during verapamil therapy, the ejection fraction did not decrease (44 +/- 8 versus 45 +/- 12 percent) and was significantly higher at identical work loads than on placebo because of a smaller increase in end-systolic volume. Oral verapamil is effective treatment for effort angina and may prevent the decrease in left ventricular ejection fraction due to exercise-induced ischemia.

Medical management of angina pectoris

The successful medical management of a patient with angina pectoris requires careful attention to many factors including omission of smoking, control of hypertension, and weight reduction for the obese person. Newer knowledge of the importance of the product of the systolic blood pressure and the pulse rate in determining the threshold of angina affords a more meaningful approach to therapy. Each individual must be educated regarding the factors that aggravate and precipitate his distress so that these can be minimized, or prophylactic nitrite therapy can be appropriately applied. Emotional stress is of equal importance to effort in the production of angina. The mainstay stay of treatment is nitroglycerin and sublingual nitrites combined with beta-blocking drugs. Each drug or combination must be properly readjusted for the individual to assure optimum benefit. Digitalis, diuretics, antiarrhythmic drugs, antihypertensive agents, and radioiodine may be useful in selected cases.