Abstract
To study the influence of a moderate dose of ethanol on the ultrastructure of myocardium in patients with heart disease, a 7·5% solution of ethanol was infused in six patients with myocardial and valvular disease, who underwent diagnostic cardiac catheterization. Before and after infusion of ethanol an endomyocardial biopsy was performed and the specimens were examined by electron microscopy. After ethanol all six patients revealed alterations in the mitochondrial structure and three of them also showed significant dilatation of the sarcoplasmic reticulum. Cardiac output increased in three of the patients, whereas in two patients a decrease of cardiac output was measured. The results suggest that the infusion of even small amounts of ethanol is able to provoke structural alterations of myocardial cell organelles and, therefore, possible impairment of myocardial function.