(December 2, 2008 - Insidermedicine) Middle-aged women who have more than 2 alcoholic drinks per day may be at increased risk for atrial fibrillation, according to research published in the Journal of the American Medical Association.

Here is some information about atrial fibrillation:

•    It is a heart rhythm disorder during which the two upper chambers of the heart quiver instead of beating properly.

•    Blood is not pumped effectively through the atria and may therefore pool there and begin to clot.

•    A blood clot that forms in one of the atria may leave the heart and travel to the brain, causing a stroke.

Researchers from Brigham and Women’s Hospital in Boston and University Hospital in Basel analyzed data from the Women’s Health Study, which included over 34,000 women over age 45 who had never experienced atrial fibrillation. The researchers looked at the association between drinking alcohol and experiencing this heart rhythm disorder.

Over 12 years of follow-up, less than 2% of the women who never drank alcohol and those who limited their consumption to 2 drinks or less per day experienced atrial fibrillation. Among those who drank more than 2 drinks a day the rate of atrial fibrillation was 2.9%, which represents 1.6 times the risk for this condition, compared with those who never drank.

We had a chance to speak with Dr. David Conen, the principal investigator of this study, who offered some further insight.

Today’s research suggests that 2 drinks a day represents a safe threshold with respect to atrial fibrillation among otherwise healthy middle-aged women.

For Insidermedicine in Depth, I'm Dr. Susan Sharma.