Health&Fitness Aken: alcohol may not be good for your health !!

Long-term drinking even moderate amounts of alcohol may increase some people's risk of stroke by causing the heart's left atrium to get bigger, the researchers said. The left atrium is the upper left chamber of the heart.

This enlargement of the left atrium can contribute to a heart condition called atrial fibrillation, in which the heart beats irregularly, said senior researcher Dr. Gregory Marcus. He's director of clinical research with the University of California, San Francisco, division of cardiology.

Atrial fibrillation causes blood to pool and clot in the left atrium. If a clot breaks free, it can block a blood vessel in the brain, causing a stroke. About 15% of people who have a stroke have atrial fibrillation first, according to the U.S. National Institute of Neurological Disorders and Stroke.

"This new information should temper any drinking that may be occurring because people think it's good for their heart," Marcus said.

But, he also noted that these findings may not apply to everyone. Some people may have a genetic predisposition for atrial fibrillation, and alcohol just makes things worse, he said.

Until now, doctors have largely considered atrial fibrillation an electrical disorder of the heart. But Marcus and colleagues suspected that atrial fibrillation also might be caused by physical changes to the heart, at least in part.

Long-term heavy drinking has been shown to cause heart failure by enlarging the lower chambers of the heart, which are known as the ventricles, Marcus said. Other lab research has determined that the atria are even more prone to alcohol-related damage than the ventricles.

The new study looked at data on 5,220 participants from the Framingham Heart Study. This study is an ongoing long-term project tracking the health of residents in the town of Framingham, Mass.

The participants' average age was 56 and slightly more than half were women. The average follow-up time was six years, according to the report.

Participants had regular electrocardiograms (EKG) to measure electrical activity of the heart. Of nearly 18,000 EKG scans taken over six years, researchers detected almost 1,100 incidences of atrial fibrillation.

The analysis revealed that an average 24% of the association between alcohol and atrial fibrillation risk could be explained by enlargement of the left atrium.