Drinking alcohol appears to have an immediate – or near-immediate – effect on heart rhythm, significantly raising the likelihood of an episode of atrial fibrillation (AFib), according to data presented at
the American College of Cardiology’s 70thAnnual Scientific Session in May.
Even just one glass of wine, beer or other alcoholic beverage can double the chance of an AFib event within the next four hours. Among people having two or more drinks in one sitting, there was a more than threefold higher chance of experiencing AFib.
“Alcohol is the most commonly consumed drug in the world, and there is still a lot we don’t understand about what it does to our bodies and, in particular, our hearts,” said Gregory M. Marcus, MD, cardiologist and professor of medicine
at the University of California, San Francisco, and the study’s lead author. “Based on our data, we found that alcohol can acutely influence the likelihood that an episode of AFib will occur within a few hours, and the more alcohol consumed,
the higher the risk of having an event.”
Marcus and his team examined data from 100 patients with paroxysmal or intermittent AFib which, unlike chronic AFib, tends to go away within a short period of time. Patients in the study were 64 years old on average; 85% of participants were white and
80% were men.
Each patient was fitted with a wearable heart monitor that continuously tracked their heart rhythm and an ankle sensor that could track alcohol consumption of more than two to three drinks on a given occasion. Participants were asked to press a button
on the heart monitor each time they had an alcoholic drink. Finger stick blood tests measuring alcohol consumption in the previous few weeks were also used to corroborate self-reported drinking events. Data showed that every 0.1% increase in
a person’s inferred blood alcohol concentration over the previous 12 hours was associated with an approximate 40% higher odds of an AFib episode. Overall, more than half (56) had an episode of AFib during the four-week study.
“Patients have been telling us that alcohol is a trigger for AFib for a long time, but it’s been hard, if not impossible, to study because there is a critical temporal relationship that requires a real-time assessment of alcohol intake and
heart rhythm,” Marcus said. “This is the first study to objectively demonstrate and quantify the real-time relationship between alcohol consumption and AFib episodes. While this study was limited to people with intermittent AFib, it’s
reasonable to extrapolate the fact that in many people alcohol may be the main trigger for an initial episode.”
Marcus said there may be other factors – such as race/ethnicity, sex, genetics or other environmental exposures – that influence alcohol’s effect on the heart in various ways and need to be studied.
In addition, people often pair alcohol with foods that are high in sodium (salt), while some pour a drink because they feel stressed, so there may be other things that play a role. The findings also run counter to previous reports about the potentially
protective role of alcohol on heart health when used in moderation.
“There is conventional wisdom that alcohol is ‘good’ or ‘healthy’ for the heart, based on observational studies, but that relates to coronary heart disease and heart attack. These new data present an interesting conundrum
regarding the overall risks versus benefits of alcohol in moderation,” Marcus said. “But the data is very clear that more is not better when it comes to alcohol; those who drink more have a higher risk of heart attack and death.”
The general recommendation for daily alcohol consumption is no more than one standard alcoholic beverage a day for women and two for men. When patients with AFib ask how they can avoid an episode, he often recommends limiting, if not eliminating, alcohol.
“But we have to consider quality of life as well, which is both relevant to arrhythmia symptoms and the opportunity to enjoy a glass of wine once in a while for some. So, it’s not as simple as instructing everyone to avoid alcohol,”
Marcus said.
The study was funded by the National Institute on Alcohol Abuse and Alcoholism.
AFib is the most common heart rhythm disorder. It is often characterized by a rapid, chaotic and fluttery heartbeat. For more information, visit CardioSmart.org/AFib.