Effects of acute alcohol infusion on duration and dispersion of QT interval in male patients with coronary artery disease and in healthy controls

Background and hypothesis: Alcohol consumption may have advantageous epidem iologic effects but ethanol also increases the risk of sudden coronary deat h. Prolongation of QT interval has been reported in chronic alcoholics. Lon g QT period predisposes to serious arrhythmias, and therefore we studied wh ether acute alcohol intoxication prolongs repolarization in patients with s table coronary artery disease (CAD). Methods: The effects of acute ethanol steady-state intravenous infusion (0. 72 g/kg body weight within 60 min) on QT interval and QT dispersion, assess ed by 12-lead electrocardiograms (ECG), were studied in 22 men with stable CAD and in 10 controls. Heart rate variability was measured by Holter recor dings. Results: Mean blood alcohol rose to 26.1 +/- 4.3 mmol/l (1.2 +/- 0.2 parts per thousand), and was maintained for 2 h. Heart rate was 56 +/- 7 beats/mi n before and 54 +/- 8 beats/min during ethanol infusion (NS). The heart rat e-adjusted QT interval increased on the average 13-23 ms over the 12-lead E CG (p < 0.005). The QT dispersion remained unaltered. The was no difference in the repolarization response in the patients with CAD compared with the controls. The high- and low-frequency components of heart rate variability remained unaltered. Conclusions: In middle aged men, regardless of the presence of CAD, moderat e amounts of alcohol cause prolongation of ventricular repolarization. Chan ges in the activity of the autonomic nervous system do not seem to explain the observed phenomenon.