Arrhythmic hearts after excessive alcohol consumption

The team from the Department of Cardiology at LMU University Hospital launched the MunichBREW I study at Munich Oktoberfest in 2015. Back then, the doctors, led by Professor Stefan Brunner and PD Dr. Moritz Sinner, studied the connection between excessive alcohol consumption and cardiac arrythmias -- but only through an electrocardiogram (ECG) snapshot.

Now the scientists wanted to gain a more detailed picture, so they set out with their mobile equipment once again. Their destinations were various small parties attended by young adults with a high likelihood "that many of the partygoers would reach breath alcohol concentrations (BAC) of at least 1.2 grams per kilogram," says Stefan Brunner. These were the participants of the MunichBREW II study -- the world's largest investigation to date of acute alcohol consumption and ECG changes in prolonged ECGs spanning several days.

Hearts out of sync -- especially in recovery phase

Overall, the researchers evaluated the data of over 200 partygoers who, with peak blood alcohol values of up to 2.5 grams per kilogram, had imbibed quite a few drinks. The ECG devices monitored their cardiac rhythms for a total of 48 hours, with the researchers distinguishing between the baseline (hour 0), the drinking period (hours 1-5), the recovery period (hours 6-19), and two control periods corresponding to 24 hours after the drinking and recovery periods, respectively. Acute alcohol intake was monitored by BAC measurements during the drinking period. ECGs were analyzed for heart rate, heart rate variability, atrial fibrillation, and other types of cardiac arrythmia. Despite the festive mood of the study participants, the quality of the ECGs was almost universally high throughout.

"Clinically relevant arrhythmias were detected in over five percent of otherwise healthy participants," explains Moritz Sinner, "and primarily in the recovery phase." Alcohol intake during the drinking period led to an increasingly rapid pulse of over 100 beats per minute. Alcohol, it would seem, can profoundly affect the autonomous regulatory processes of the heart. "Our study furnishes, from a cardiological perspective, another negative effect of acute excessive alcohol consumption on health," emphasizes Brunner. Meanwhile, the long-term harmful effects of alcohol-related cardiac arrythmias on cardiac health remains a subject for further research.