The proarrhythmic conundrum of alcohol intake.

The arrhythmogenic potential of alcohol consumption that leads to cardiac arrhythmia development includes the induction of both atrial and ventricular arrhythmias, with atrial fibrillation (AF) being the commonest alcohol-related arrhythmia, even with low/moderate alcohol consumption. Arrhythmias occur both with acute and chronic alcohol use. The "Holiday Heart Syndrome" relates to the occurrence of AF, most commonly following weekend or public holiday binge drinking; however, other arrhythmias may also occur, including other supraventricular arrhythmias, and occasionally even frequent ventricular premature beats and a rare occurrence of ventricular tachycardia. Arrhythmias in individuals with alcohol use disorder, in addition to AF, may comprise ventricular arrhythmias (VAs) that may be potentially fatal leading to cardiac arrest. The effects of alcohol on triggering VAs appear to be dose-dependent, observed more commonly in heavy drinkers, both in healthy individuals and patients with underlying structural heart disease, including ischemic heart disease and alcoholic cardiomyopathy. Men appear to be affected at higher dosages of alcohol, while women can suffer from arrhythmias at lower dosages. On the other hand, low to moderate consumption of alcohol may confer some protection from serious VAs and cardiac arrest (J- or U-curve phenomenon); however, abstinence is the optimal strategy. These issues as they relate to alcohol-induced proarrhythmia are herein reviewed, with the large studies and meta-analyses tabulated and the arrhythmogenic mechanisms pictorially illustrated.