Acute electrical, autonomic and structural effects of binge drinking: Insights into the ‘holiday heart syndrome’

Background: Binge drinking is a common atrial fibrillation (AF) trigger, however the mechanisms are poorly understood. Objective: To investigate the effects of alcohol intoxication and hangover with rhythm monitoring and cardiac MRI. Methods: Patients underwent serial cardiac MRI pre- and post-binge with continuous Holter monitoring. Time periods analyzed: baseline (24 h pre-binge), consumption, hangover (0– 24 h post-consumption) and post-hangover (24–48 h post-consumption). Results: 50 patients (age 49 ± 15 years, 40% paroxysmal AF) completed the study (intake 8.4 ± 3.1 standard drinks). Mean heart rate increased from 72 ± 10 to 80 ± 13 beats per minute (bpm) during consumption (p < 0.001). The hangover period was characterised by higher daily atrial ectopic count (50, IQR 10–132 vs baseline 43, IQR 10–113; p = 0.04) and reduced heart rate variability (SDNN 55 ms, IQR 40–65 versus 62 ms, IQR 51–66; p = 0.007). There was evidence of heightened parasympathetic activity post-hangover with heart rate slowing (mean HR 54 ± 6 bpm; p = 0.03) and increased activity in the High frequency band when separating the complex heart rate variability waveform into its component rhythms (291 ms², 97–538 versus baseline 237 ms², IQR 104–332; p = 0.04). Three patients developed AF 11, 29 and 34 h post-binge. Cardiac MRI (2.7 ± 0.7 days post-binge) demonstrated a decrease in left atrial (LA) emptying fraction (57.9 ± 8.5 to 53.5 ± 6.7%; p = 0.003) but no change in LA volume, left ventricular ejection fraction or markers of ventricular inflammation. Conclusion: Binge drinking is associated with sympathetic activation followed by a ‘rebound’ parasympathetic response and atrial mechanical dysfunction which may explain the propensity and temporal association between binge drinking and AF.