Heavy Drinking May Trigger Irregular Heart Rhythm

(Page 2)

And, according to the study authors, binge drinking has also been associated with atrial fibrillation in the past, even though data on long-term alcohol consumption and risk is less clear.

For this study, all patients arriving at an arrhythmia clinic at Charing Cross Hospital in London with symptoms of a new cardiac arrhythmia were asked about their weekly alcohol consumption.

Participants were grouped according to how much they drank: teetotaler (those who abstained completely), moderate drinkers (1-14 units per week for females and one to 21 units per week for males) and excessive (anything greater than moderate). In the study, two units were about equal to one pint of beer.

Those with confirmed atrial fibrillation were then compared to those without the irregular heart beat.

About half (48 percent) of people in each group were moderate drinkers, suggesting no increase in risk.

Excessive drinking, however, was much higher in patients with atrial fibrillation than in patients without (27 percent versus 17 percent, respectively).

In fact, these heavy drinkers raised their risk of atrial fibrillation by 2 percent for each additional unit they drank compared to non-drinkers.

It's not clear how alcohol and rhythm disturbances might be linked, but the experts offered up some theories.

One is that heavy drinking ramps up the body's "fight-or-flight" response, Erwin said. Another is that drinking can raise the level of fatty acids in the bloodstream.

"Several mechanisms have been suggested from very small studies, including the high adrenaline state of drinking and alcohol withdrawal and impaired vagal heart rate control," Martins said.

Cutting down on drinking could lower the risk, he said.

"We found that nearly one in five of all 984 patients that we evaluated in our study admitted to drinking more than the recommended level," Martins said. "If this behavior could be modified, one might speculate that it could potentially result in a significant reduction in the number of new AF cases."

More information

There's more on atrial fibrillation at the American Heart Association.