Excessive alcohol intake can mess up the normal rhythm of the heart and bring on cardiac arrhythmias, a new study shows – adding to concerns about the negative health impacts of binge drinking.
The research by a team in Germany builds on previous studies looking at how alcohol can lead to faster and more irregular heartbeats.
We've known about holiday heart syndrome – heartbeat variations while drinking – for decades. Here, the team monitored partygoers in real time as they were boozing, tracking the consequences across specific phases.
Ahead of a planned night of heavy drinking, 193 volunteers were given mobile electrocardiogram (ECG) monitors to track their heart rates during the drinking period (hours 1–5) and the recovery period (hours 6–19).
"Clinically relevant arrhythmias were detected in over five percent of otherwise healthy participants, and primarily in the recovery phase," says cardiologist Moritz Sinner from the Ludwig Maximilian University of Munich (LMU Munich).
The partying participants recorded peak blood alcohol values that averaged 1.4 grams per kilogram – a high enough blood alcohol content to impact multiple body systems.
As for the cardiac arrhythmias observed in 10 of the participants, they included atrial fibrillation (abnormal beating in the atrial chambers) and ventricular tachycardias (abnormal beating in the ventricles). Heart rates of over 100 beats per minute were recorded in some cases.
In one example, an otherwise healthy, 26-year-old male developed a case of atrial fibrillation about 13 hours after he stopped drinking, which lasted for 79 minutes. The man had no previous history of atrial fibrillation.
Four participants experienced some degree of heart block – interference with the 'when to beat' signals that normally travel from the atria to the ventricles. In the most serious case, a healthy 29-year-old woman experienced a third-degree heart block during the recovery phase that lasted 15.4 seconds.
We know that drinking affects the body's autonomic nervous system, meaning increases in heart rates and stress levels, but it's not yet clear what the consequences might be for overall health or long-term disease risk.
"Our data supports the understanding that an alcohol-induced modulation of the autonomic nervous system is mediating the arrhythmia incidence," write the researchers in their published paper.
"Taken together, the holiday heart syndrome remains rare in otherwise healthy individuals, but should be recognized as a relevant health problem."
Any change in the normal beat of the heart can potentially be dangerous, whether it's caused by the death of a loved one or a bad reaction to medication. It's important that future studies look in closer detail at why these changes might be happening, and what the consequences could be.
It's another reason to always drink in moderation: too much alcohol has been linked to cardiovascular disease, shifts in our genes, extensive liver damage, an increased risk of cancer, and much more besides.
"Our study furnishes, from a cardiological perspective, another negative effect of acute excessive alcohol consumption on health," says cardiologist Stefan Brunner, from LMU Munich.
The research has been published in the European Heart Journal.
