In the definitive report, Marvin Bacaner, M.D., University of Minnesota, describes the effects of the antiarrhythmic drug bretylium tosylate in preventing dangerous heart rhythm disorders and other complications after AMI.
Bretylium works by blocking release of the "fight or flight" hormone adrenaline, preventing activation of the sympathetic nervous system. Given intravenously, bretylium was once the mainstay of treatment for ventricular fibrillation and other heart rhythm disorders after AMI, although in recent years it has been largely replaced by other drugs.
However, Dr. Bacaner now believes that bretylium may offer unique advantages in heart attack treatment, and that it can be given effectively orally. In a study of 110 patients with AMI, potentially deadly arrhythmias developed in just 8 percent of patients treated with bretylium, compared to 65 percent of those treated with a different drug, liodcaine.
Bretylium's adrenaline-blocking effect may lead to other benefits as well. In 31 percent of patients taking bretylium, the evolving heart attack did not develop into a "true" myocardial infarction, with permanent damage to the heart muscle. In contrast, 95 percent of patients treated with lidocaine developed a large heart attack.
A clue to the importance of blocking the sympathetic nervous system was that bretylium-treated patients remained warm and dry, with normal skin color. In contrast, patients receiving lidocaine were pale, sweaty, and cool, all signs of sympathetic nervous system activation.
Taken together, the findings suggest that the sympathetic nervous system plays an important role in the development o
Contact: Molly Portz
University of Minnesota