THE EFFECT OF THE INGESTION OF ETHANOL ON OBSTRUCTION OF THE LEFT-VENTRICULAR OUTFLOW TRACT IN HYPERTROPHIC CARDIOMYOPATHY

Background Ethanol causes vasodilatation, which might have an adverse effect, due to increased obstruction of the left ventricular outflow t ract, in patients with hypertrophic obstructive cardiomyopathy. We ass essed the hemodynamic effects of the ingestion of ethanol, in an amoun t commonly consumed socially, in patients with hypertrophic cardiomyop athy. Methods We performed echocardiography in 36 patients before and several times after the ingestion of either 50 ml of 40 percent ethano l or an isocaloric placebo with the aroma of rum. Each patient receive d both ethanol and placebo, on different days. The patients, but not t he physicians, were blinded to the content of the drink. We measured t he sizes of the left atrium and left ventricle, the left-ventricular-w all thickness, blood pressure, heart rate, the degree of systolic ante rior motion of the mitral valve, and the pressure gradient across the left ventricular outflow tract. Results The ingestion of ethanol resul ted in a significant drop in the mean (+/-SD) systolic blood pressure (from 130.5+/-18.6 to 122.5+/-20.3 mm Hg, P<0.001), a significant incr ease in systolic anterior motion of the mitral valve (from a grade of 2.1 to a grade of 2.5, P<0.001), and a 63 percent increase in the mean gradient across the left ventricular outflow tract (from 38.1+/-26.5 to 62.2+/-42.4 mm Hg, P<0.001). These changes, which were not associat ed with symptoms, did not occur after the ingestion of placebo. Conclu sions The ingestion of a small amount of ethanol caused an increase in the gradient across the left ventricular outflow tract in patients wi th hypertrophic obstructive cardiomyopathy, which could have an advers e clinical effect.