Heart beat problem 'largely avoidable'
Over half of all cases of the most common type of heart rhythm disturbance could be avoided by "clean living", such as avoiding smoking and eating more healthily, say scientists.
If individuals were to maintain a healthy weight and normal blood pressure and abstain from tobacco 57% of cases of atrial fibrillation (AF) could be averted, the US experts say.
The study in Circulation journal is based on nearly 15,000 patients.
AF is a major cause of stroke.
Yet many people are unaware that they have this heart condition because often it causes very few symptoms.
Experts believe up to 500,000 people in the UK have AF.
The condition can be treated with medication to slow the irregular heartbeat and blood-thinning drugs to reduce stroke risk, but the latest research shows how much illness could be avoided by simple lifestyle measures.
Dr Alvaro Alonso, who led the research at the University of Minnesota School of Public Health, said: "We now know that a significant proportion of all cases of atrial fibrillation can be avoided.
"Ideally, if individuals were able to maintain a normal blood pressure and healthy body weight and didn't smoke, not only would it reduce their risks for other forms of cardiovascular disease, such as heart disease and stroke, but it also would significantly impact the risk of developing atrial fibrillation in later life."
Only 5% of the people in the study had a lifestyle that would be deemed healthy enough to cut their risk of AF.
Over a period of 17 years, 1,520 episodes of AF were noted among the participants, and 57% of these episodes were linked to clear risk factors such as high blood pressure, diabetes or smoking.
The findings suggest over 860 of the events might have been avoided by "clean living".
Dr Mike Knapton, associate medical director at the BHF, said: "This study shows not only can you identify people with AF and treat them to reduce their risk of stroke, AF can also be prevented in the first place with simple messages about lifestyle changes."
He said the difficulty was helping people to make healthy choices when their environment and society often encouraged unhealthy options.