The level of acute alcohol exposure during binge drinking associates with the extent of cardiac response.

Introduction: 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.

Methods: 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.

Results: 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.

Discussion: 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.