Moderate alcohol consumption is associated with atrial electrical and structural changes: insights from high-density left atrial electroanatomic mapping

Background: Regular alcohol intake is an important modifiable risk factor associated with atrial fibrillation (AF) and left atrial (LA) dilation. Objective: The purpose of this study was to determine the impact of different degrees of alcohol consumption on atrial remodeling using high-density electroanatomic mapping. Methods: We enrolled 75 patients before AF ablation to undergo high-density LA mapping (CARTO, Biosense Webster) using a multipolar catheter. The Confidense algorithm was used to create maps during distal coronary sinus pacing at 600 ms. Bipolar voltage and complex atrial activity were assessed, and isochronal activation maps were created to determine global conduction velocity (CV). Patients were classified as lifelong nondrinkers, mild drinkers (2–7 drinks/week), or moderate drinkers (8–21 drinks/week). Results: High-density electroanatomic mapping (mean 1016 ± 445 points per patient) was performed on 25 lifelong nondrinkers, 25 mild drinkers (4.4 ± 2.3 drinks/week), and 25 moderate drinkers (14.0 ± 4.2 drinks/week). Moderate drinkers had significantly lower mean global bipolar voltages (1.53 ± 0.62 mV vs 1.89 ± 0.45 mV; P =.02), slower CV (33.5 ± 14.4 cm/s vs 41.7 ± 12.1 cm/s; P =.04), and a higher proportion of complex atrial potentials (7.8% ± 4.7% vs 4.5% ± 2.7%; P =.004) compared to nondrinkers. Global voltage and CV did not differ significantly in mild drinkers, but there was a significant increase in global complex potentials (6.6% ± 4.6%; P =.04) and regional low-voltage zones (<0.5 mV) in the septum and lateral wall (P <.05) compared with nondrinkers. Conclusion: Regular moderate alcohol consumption, but not mild consumption, is an important modifiable risk factor for AF associated with lower atrial voltage and conduction slowing. These electrical and structural changes may explain the propensity to AF in regular drinkers.