Beta-adrenergic receptor blockers as therapy in pediatric chronic heart failure.

Beta-adrenergic receptor blocking agents (beta-blockers) are now considered to be standard of care for the treatment of chronic congestive heart failure in adults. Studies in adults with chronic heart failure have shown that beta-blockers improve left ventricular ejection fraction, symptoms, and survival when compared to placebo. New mechanisms of actions in individual beta-blockers are being continually elucidated, but the primary mechanism of action of beta-blockers in chronic heart failure is thought to be the prevention and/or reversal of adrenergically-mediated intrinsic myocardial dysfunction and remodeling. Experience with the use of beta-blockers in children with heart failure is limited but growing. Although no randomized, placebo-controlled data yet exists, anecdotal evidence suggests that children with chronic congestive heart failure may also benefit from this therapy. There are now uncontrolled safety and efficacy studies showing possible benefit from both metoprolol and carvedilol in children with heart failure due to either large left-to-right shunt or systemic ventricular dysfunction. Large prospective, randomized trials in children are currently underway in order to attempt to determine the indications, dosages, and optimal use of beta-blockers in children with chronic congestive heart failure.