Obesity may cause irregular heartbeat

Obesity raises the risk of atrial fibrillation, an abnormal heartbeat that can lead to stroke and early death if not controlled, researchers report.

“What we found is that obesity was associated with an approximately 50% increase in the risk of developing atrial fibrillation,” Dr. Thomas Wang of the Framingham Heart Study said last week.

The researchers tracked more than 5,200 middle-aged adults for an average of 14 years, during which 526 developed atrial fibrillation, mostly due to changes in the structure of the heart blamed on weight gains.

Obesity can cause the heart’s left atrium, an upper chamber that receives oxygenated blood circulated from the lungs, to become dilated and beat abnormally fast, throwing off the organ’s rhythm, according to the study published in the Journal of the American Medical Assn.

“Once you get atrial fibrillation, it may be very difficult for doctors to get you back into the normal rhythm, and what that means for the patient is that the patient may be stuck with a lifetime of taking medications to protect against stroke and the other complications of atrial fibrillation,” Wang said. Beta blockers are often used to treat irregular heartbeat, but they can have side effects, such as aggravating symptoms of lung disease or reducing limb circulation.