Noninvasive Estimation of Myocardial Performance in Patients with Diabetes: Effect of Alcohol Administration

Abstract

Systolic time intervals (STIs) were determined in 19 diabetic patients under age 50 (mean age 35.2 years) and 24 normal control subjects (mean age 30.6 years). Preëjection period (PEP), left ventricular ejection time (LVET), and PEP-LVET ratio were obtained by the conventional manner. Preëjection period index (PEPI) and left ventricular ejection time index (LVETI) were derived by Weissler's formula.14 The isovolumic relaxation time (IVRT) was measured: (1) from the aortic component of the second heart sound of the phonocardiogram to the rapid opening anterior motion of the anterior leaflet of the mitral valve on echocardiogram (A2D1), (2) and to the “0” point of the apexcardiogram (A2O). PEP, LEVT, PEPI, LVETI, and PEP/LVET ratio were statistically similar in diabetics and controls. However, the A2D1 was longer in diabetics (71.2 ± 3.4 msec.) than in control subjects (59.5 ±3.1 msec.) (p < 0.02). Effects of oral ethanol (0.7 gm./kg.) administered over 20 minutes to 12 diabetics (group 1) and seven control subjects (group 2) were studied before and at 15, 30, 60, and 90 minutes after ingestion. No change in STIs occurred in group 2 (controls) but the heart rate, PEPI, and PEP/LVET ratio rose in group 1 (diabetics). There were significant differences in PEPI and PEP/LVET ratio between groups 1 and 2, 30 and 60 minutes after alcohol. IVRT remained unchanged. Maximum blood alcohol levels for both groups were comparable at 60 minutes, (67.8 ± 5.2 mg./100 ml. in group 1 and 66.7 ± 7.5 mg./100 ml. in group 2). Glucose levels, although higher in group 1, remained stable throughout for both groups. Lactate levels, after alcohol ingestion, were comparable in both groups. Although the only evidence of myocardial dysfunction noted in diabetic patients in the resting state was the increase in IVRT, their response to alcohol revealed further changes in cardiac function not seen with such low doses of ethanol in normal individuals.