Drinking small amounts of alcohol frequently is linked with a higher likelihood of atrial fibrillation than binge drinking, says a new study.

Atrial fibrillation is the most common heart rhythm disorder and raises the risk of stroke by five-fold. Symptoms include palpitations, racing or irregular pulse, shortness of breath, tiredness, chest pain and dizziness. "Our study suggests that drinking less often may also be important to protect against atrial fibrillation," said study author Jong-Il Choi, from Korea University College in South Korea. For the study, published in the journal EP Europace, researchers examined the relative importance of frequent drinking versus binge drinking for new-onset atrial fibrillation.

The analysis included 9,776,956 individuals without atrial fibrillation who underwent a national health check-up in 2009 which included a questionnaire about alcohol consumption. Participants were followed-up until 2017 for the occurrence of atrial fibrillation. The number of drinking sessions per week was the strongest risk factor for new-onset atrial fibrillation. Compared with drinking twice per week (reference group), drinking every day was the riskiest, with a hazard ratio (HR) of 1.412, while drinking once a week was the least risky (HR 0.933).

Binge drinking did not show any clear link with new-onset atrial fibrillation. "Our study suggests that frequent drinking is more dangerous than infrequent binge drinking with regard to atrial fibrillation," Choi said. The number of drinking sessions was related to atrial fibrillation onset regardless of age and sex. Repeated episodes of atrial fibrillation triggered by alcohol may lead to overt disease, the research notes. In addition, drinking can provoke sleep disturbance which is a known risk factor for atrial fibrillation.

There was a two per cent increase in the risk of new-onset atrial fibrillation for each gram of alcohol consumed per week. Compared to mild drinkers, those who drank no alcohol, moderate, or high amounts had 8.6 per cent, 7.7 per cent, and 21.5 per cent elevated risks, respectively, the study said.