Obese people who suffer with atrial fibrillation (AF) can reduce or even reverse the effects of the condition by losing weight, researchers have shown for the first time.

AF causes irregular and rapid heartbeats, which can make the heart less efficient at pumping blood around the body. This can lead to symptoms such as palpitations, breathlessness, dizziness, angina and the development of blood clots.

The condition is a major risk factor for stroke and can lead to heart failure. Millions of people around the world are affected, including around 40,000 people over the age of 50 in Ireland.

Australian researchers decided to look into the impact of weight on the progression of AF. They carried out a long-term follow-up study of 355 AF patients who had a body mass index (BMI) of more than 27. A BMI of 25-30 is considered overweight, while over 30 is considered obese.

The study found that a 10% weight loss, along with the management of associated risk factors, could reduce AF symptoms or even reverse disease progression.

"The study showed that if obese people lose more than 10% of their weight and subsequent management of other risks to their lifestyle, they can reverse the progression of the disease. People who lost weight experienced fewer symptoms, required less treatment and had better outcomes. Those who previously had sustained symptoms experienced only intermittent symptoms or indeed stopped experiencing AF entirely," explained the study's lead author, Melissa Middeldorp, of the University of Adelaide.

She pointed out that AF is a progressive disease, ‘in which initial short, intermittent symptoms develop into more sustained forms of the condition'.

She noted that obesity and lifestyle factors are associated with AF progression, but this progression is also shown to have ‘a direct link with the degree of weight loss'.

"Without weight loss, there is a progression to more persistent forms of AF," she said.

Commenting on the findings, AF expert, Prof Prash Sanders, of the Centre for Heart Rhythm Disorders, said that these findings show that weight loss and the treatment of lifestyle factors are ‘essential components for effectively managing AF', and in many instances, may even be alternatives to surgery and medication.

"This work has widespread implications for the management of this disease globally and is good news for people with the condition. With record levels of obesity in most high-income countries, this study gives hope that obese people can have a better quality of life, as well as reducing their dependence on healthcare services, if they lose weight," he added.

Details of these findings are published in the heart journal, Europace.