Acute Effects of Low Doses of Red Wine on Cardiac Conduction and Repolarization in Young Healthy Subjects

Background: Moderate to high blood concentrations of ethanol have been shown to yield acute changes in cardiac electrophysiological properties, but the effect of low concentrations have never been assessed. The role of concomitant changes in clinical variables or cardiac dimensions is also still unknown. This study aimed at exploring the acute effects of low doses of ethanol, administered as Italian red wine, on conduction, depolarization, and repolarization electrocardiographic (ECG) intervals in a population of healthy subjects. Methods: Forty healthy young volunteers drank a low quantity of red wine (5 ml/kg), and an equal volume of fruit juice in separate experiments. Heart rate, P-wave duration, PR interval, QRS duration, QT interval, corrected QT interval, QT dispersion, and corrected QT dispersion were assessed at baseline and after 60 minutes from challenge. Results: Mean blood ethanol concentration after drinking was 0.48 +/- 0.06 g/l. Compared to the control challenge, significant changes after red wine intake were observed in P-wave duration (from 101 +/- 11 to 108 +/- 14 milliseconds, p = 0.0006), PR interval (from 153 +/- 15 to 167 +/- 17 milliseconds, p < 0.0001), QT interval (from 346 +/- 28 to 361 +/- 24 milliseconds, p < 0.0001), and corrected QT interval (from 388 +/- 24 to 402 +/- 30 milliseconds, p = 0.0006). None of these changes showed correlations with modifications in clinical or echocardiographic variables. In multivariate analyses aimed at exploring predictors of ECG changes, none of the variables entered the final models. Conclusions: Low doses of red wine acutely slow cardiac conduction and prolong repolarization in normal individuals. These changes are poorly predictable. The potential arrhythmogenic impact of these effects is worthy of exploration.