The cardiovascular effects of acute alcohol exposure remain incompletely understood, despite its reported association with arrhythmias like atrial fibrillation (AF). The Munich-BREW II study supported a link between excessive alcohol consumption, elevated heart rate, impaired heart rate variability (HRV), and increased arrhythmia incidence. Here, we present sub-analyses exploring how the amount of congested alcohol during binge drinking and the maximum breath alcohol concentration (BAC) influence these findings.

The Munich-BREW II study is a prospective, single-center cohort study conducted at LMU University Hospital, Munich between October 2016 and July 2017. Participants consumed alcohol under supervision, with hourly BAC measurements and continuous 3-lead Holter monitoring for ECG analyses of heart rate, HRV, and arrhythmias. Subgroup analyses stratified participants by quartiles of alcohol consumption and peak BAC, respectively.

We analyzed 193 participants (mean age 29.9 ± 10.6 years, 36% women). Subgroup analyses revealed that higher alcohol intake during binge drinking correlated with significantly elevated heart rate (p < 0.001) and suppressed HRV measures (SDNN, p = 0.003; RMSSD, p = 0.001). Similarly, higher BAC levels were associated with increased heart rates (p < 0.001) and both reduced SDNN (p < 0.001) and RMSSD (p = 0.002). Both subgroups indicated a more pronounced effect in the highest quartile. Clinically relevant arrhythmias were not differentially distributed across subgroups.

In this subgroup analysis of the Munich-BREW II study, higher alcohol intake and BAC during binge drinking were associated with increased heart rate and suppressed cardiac autonomic tone. The results suggest a dose response relation and discourages excessive alcohol use. Further research will need to investigate the degree of alcohol exposure to modify clinical outcomes.

Illustrates key results—A: The exemplary glasses are filled with the beverages consumed at the median level by men and women, respectively. The fill level in each glass corresponds to the median amount of beverage consumption in liters. Colors represent types of beverages (yellow: beer, pale orange: liquor, orange: long drinks and red: wine). B and C: Boxplots represent the number of drinks and the breath alcohol concentration (BAC) for men and women, respectively. The median is illustrated by a black line, the mean by a red dot. Boxes indicate interquartile range. D: Graphs visualize the trend of heart frequency (red) and standard deviation of R-R intervals (SDNN; yellow) with increasing breath alcohol concentration (from left to right)