The Munich Oktoberfest might seem an unlikely locale for a medical research project, but German scientists studied festivalgoers and found that moderate social drinking may lead to arrhythmias — irregular heart rhythms — in otherwise healthy people.

Using a hand-held breathalyzer, the researchers tested 3,028 men and women who had been drinking but were not legally impaired. They gave them EKGs to test heart function.

More than a quarter of the group had a condition called sinus tachycardia, marked by a resting heart rate of more than 100 beats per minute. About 1 to 2 percent of the general population have repeated episodes of tachycardia, which in some cases can pose risks.

They also found slightly increased, but not statistically significant, levels of other kinds of irregular heartbeats, including the heart palpitations of atrial fibrillation, a potentially serious condition. The arrhythmias increased with higher breath alcohol levels.

The study, in the European Heart Journal, controlled for age, sex, smoking, medication use and a history of heart disease.

The lead author, Dr. Moritz F. Sinner, an assistant professor of cardiology at University Hospital Munich, said that in most people, elevated heart rates would be expected to subside as alcohol concentrations went down. He suspects “that people susceptible to developing arrhythmias because of some undiagnosed condition might develop an arrhythmia under the stress of alcohol,” and that some could end up requiring treatment.