[Beta receptor blockers in chronic heart failure]

Abstract

Recently published data of the controlled MDC- and CIBIS-trials confirm the favorable effect of beta-blocker therapy on the hemodynamics and clinical course of patients with chronic heart failure due to dilatated and/or ischemic cardiomyopathy. However, mortality remains unchanged. The mechanisms by which beta-blocker therapy improves hemodynamics in chronic heart failure are not known reliably. It is postulated that the negative chronotropic effect of beta-blockers improves the cellular calcium metabolism and thereby increases myocardial contractility. Further effects of beta-blockers are protection of myocardial cells from enhanced catecholamine concentrations. This prevents cell necrosis and economizes the use of cell energy. The reversion of down-regulation of beta-1-receptors in beta-blocker therapy is most probably only an epiphenomenon. Major randomized clinical trials are ongoing to investigate whether improved hemodynamics and clinical course are correlated with decreased mortality. It also still remains open which substance is most beneficial (e.g., selective beta-blockers, beta-blockers with additional vasodilatatory effect).