Occasional heavy drinking was defined as having 5 or more standard drinks in a day at least 12 times per year. "Regular" heavy drinkers - those who averaged at least 5 drinks per day, were excluded from the analysis.

In general, moderate drinking - a drink or two per day - is considered a potentially heart-healthy habit. A number of studies have found that moderate drinkers have lower risks of heart disease than teetotalers do.

Research suggests that alcohol can increase "good" HDL cholesterol, has anti-inflammatory effects in the blood vessels and may make the blood less prone to clotting.

On the other hand, regular heavy drinking may increase blood pressure, promote blood clotting and contribute to development of arrhythmias.

References:
Occasional binges may undo alcohol's heart benefits. Reuters, 2010.