Therapeutic controversies with use of beta-adrenoceptor blockade in heart
failure.
Author(s): Ikram H, Fitzpatrick D, Crozier IG.
Affiliation(s): Princess Margaret Hospital, Chistchuch, New Zealand.
Publication date & source: 1993, Am J Cardiol. , 71(9):54C-60C
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.
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