Mildly Intoxicating Levels of Alcohol Produces Direct Myocardial Depression on Left Ventricular Performance

Abstract

Previous studies of the effect of mildly intoxicating amounts of alcohol on left ventricular (LV) performance in conscious subjects have produced conflicting results. This may have resulted from the confounding influence of alcohol produced changes in loading conditions on conventional measures of LV performance. Accordingly, we recently used load- insensitive pressure (P)-volume (V) analysis of LV performance to assess the effect of alcohol (0.2 gm/kg, iv, blood level 67±14 mg/dl) in 10 conscious dogs. LV V was determined from three LV internal dimensions. Three relations that provide load-insensitive measures of LV performance were determined from variability loaded P-V loops produced by caval occlusions. Alcohol significantly decreased the slopes of the LV end-systolic P-V relation (14.7±2.2 vs 9.2±1.3 mmHg/ml, mean + SD, p<0.05), the dP/dt_max-end-diastolic volume (V_ED) relation (135.2±18.5 vs 99.1±15.9 mmHg/sec·ml, p<0.05) and the stroke work-V_ED relation (90.1±15.9; 85.2±9 mmHg, p<0.05). All three relations were shifted toward the right, indicating a depression of LV contractile performance. Similar, but more marked cardiac depression, was observed following autonomic blockade.

We conclude that mildly intoxicating levels of alcohol (blood concentration < 100 mg/dl) are capable of producing myocardial depression in conscious animals, which are more marked after autonomic blockade. This suggests that patients with impaired LV function should avoid even small amounts of alcohol.