Initial experience with beta blockers in dilated cardiomyopathy.

In early 1973, Waagstein administered bolus intravenous injections of practolol and, subsequently, alprenolol, 50 mg twice daily, to reduce the heart rate of a 59-year-old woman with refractory, idiopathic dilated congestive cardiomyopathy (DCCM) and resting tachycardia. The patient's condition improved dramatically and continued to improve during subsequent oral therapy. This experience, combined with increasing interest in the role of beta blockade in myocardial protection, led to investigation of oral practolol, 50-400 mg twice daily, for 2-12 months in 6 additional patients with advanced DCCM. These findings, published in 1975, indicated improved ventricular function for all participants. In a 1980 open-label follow-up study, 28 patients with DCCM received alprenolol, metoprolol, practolol, or propranolol. Treatment was associated with improvements in myocardial function as well as in related symptomatology. These effects were reversed following drug withdrawal. The findings suggested that beta blockers possessed potential value in treatment of idiopathic DCCM.