WASHINGTON — When it comes to alcohol, doctors continue to find there’s a fine line between how much is good or bad for the heart. While studies point to drinking in moderation being helpful for cardiovascular health, a new report reveals even one drink may be too much for patients with a common heart rhythm disorder. Researchers say having a drink can lead to an almost-immediate episode of atrial fibrillation.

Their study discovered just one glass of wine, beer, or any other alcoholic drink doubles the chances of having a heart rhythm disturbance within the next four hours. For people having two drinks or more, their odds of suffering an AFib episode increased by more than three times.

Study authors monitored a group of older patients with intermittent AFib for four weeks. Using an alcohol sensor to monitor each person’s drinking, researchers found that every 0.1 percent increase in blood alcohol concentration over the previous 12 hours resulted in a 40 percent higher risk of an AFib episode.

“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,” says study lead author Gregory M. Marcus, MD, in a media release. “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.”

What is atrial fibrillation?

AFib is one of the most common heart rhythm disorders, with nearly three million Americans currently living with the condition. It can cause a quivering or irregular heartbeat resulting in poor blood flow, clots, and even strokes.

In the new study, researchers examined 100 patients with an average age of 64 dealing with intermittent AFib. This form of the condition tends to come and go within a short period of time, which is different and less severe than chronic AFib. The study notes this group was mostly white (85%) and involved mainly male patients (80%).

The team reviewed each person’s medical history, prescription drug use, and lifestyle habits before the experiment. The group was also outfitted with wearable heart monitors and ankle monitors to keep track of their alcohol consumption. Although researchers asked each person to press a button on the heart monitor each time they had a drink, their ankle sensor could also detect when someone consumed over two alcoholic beverages. Over the course of the month-long study, 56 of the 100 participants had an episode of AFib.

“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,” says Dr. Marcus, a cardiologist and professor of medicine at the University of California-San Francisco. “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.”

So is alcohol good or bad for the heart?

Study authors caution that there may be other factors influencing the link between AFib and drinking. For example, researchers say drinkers often pair alcohol with salty foods or consume more alcohol when they feel stressed. The differences between race, gender, and environmental conditions may also play a role in the risk for AFib.

The new findings also paint a much different picture in comparison to other studies on alcohol and heart health. A recent report discovered drinking in moderation appears to provide a boost to the brain-heart connection. That study found alcohol can lower stress-related signals which lead to heart disease.

“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 explains. “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.”

How much is too much when drinking?

The cardiologist adds this study shows why it’s important to identify patients at high risk for atrial fibrillation. While those who are not at significant risk for heart failure may benefit from alcohol’s effects, others may be putting themselves in danger with their first sip. Health experts generally recommend that women have no more than one alcoholic beverage a day and two for men.

“Still, when patients ask me what they can do to avoid an AFib episode, I tell them the evidence suggests that they should minimize, if not completely eliminate, 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 concludes.

Researchers presented their findings at the American College of Cardiology’s 70th Annual Scientific Session.

About Chris Melore

Chris Melore has been a writer, researcher, editor, and producer in the New York-area since 2006. He won a local Emmy award for his work in sports television in 2011.

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