Therapeutic controversies with use of beta-adrenoceptor blockade in heart failure.

In response to early reports indicating a beneficial adrenoceptor effect of beta blockade, 2 small trials were conducted to investigate the hemodynamic effects of acute and chronic beta-adrenoceptor blockade in patients with congestive cardiomyopathy. Acute beta-blocker therapy with intravenous acebutolol, 25 mg, resulted in a significant decline in cardiac performance, whereas chronic therapy with acebutolol, 200 mg twice daily, resulted in no beneficial effects on exercise tolerance, as reported by the original Swedish investigators. Further, beta-adrenoceptor blockade has been associated with a number of clinical problems: beta blockers tend to interfere with the compensatory mechanisms that support circulation during early or mild heart failure and therefore have little value as routine therapy at that stage of the disorder. Although excessive beta-adrenoceptor blockade may worsen ventricular function by decreasing myocardial contractility, beta blockers appear to have a useful role in patients with moderate heart failure accompanied by tachycardia. Carefully titrated doses of beta blockers in conjunction with afterload-reducing agents may also provide a benefit in patients with rapid heart rates and grossly elevated levels of circulating catecholamines.