Beta receptor antagonists in the treatment of heart failure.

The use of beta-receptor antagonists in the treatment of heart failure is controversial. Available data do not allow general recommendations regarding their use. In dilated cardiomyopathy, several studies suggest that long-term treatment in individual patients reduces symptoms and increases exercise capacity. Short-term treatment is usually not beneficial, except in patients with ischemically induced left ventricular dysfunction. In heart failure, post myocardial infarction and in chronic ischemic heart disease, no proper long-term study has been performed to evaluate its effects. However, patients with acute myocardial infarction tolerate beta blockers, despite the presence of left ventricular dysfunction and long-term prognosis is improved. Newer agents, some with ancillary properties, such as intrinsic activity and vasodilatation, may have advantages. In the future we need a better description of the cardiac status in our patients in order to be able to select those that will respond favorably to beta-receptor antagonists. The mechanisms by which some patients improve are still obscure. Protection against receptor downregulation, restoration of receptor density, protection against cardiotoxicity of catecholamines, and improvement in ischemic systolic and diastolic left ventricular function are all possible. The fear that beta-receptor antagonists are dangerous in heart failure is in most instances not warranted, but an initial deterioration may have to be accepted in order to gain long-term beneficial effects. Ongoing studies in both idiopathic cardiomyopathy and in postinfarction failure will hopefully help us to define the use of beta-adrenoceptor antagonists in the future.