Yoga, already proven to lower high blood pressure and cholesterol levels, can cut in half the risk of a common and potentially dangerous irregular heartbeat, according to a U.S. study released on Saturday.

The small study was the first to examine the benefits of yoga on atrial fibrillation -- a problem that is a leading cause of stroke and is most common in the elderly.

In addition to halving the episodes of atrial fibrillation, the study found that yoga also reduced symptoms of anxiety and depression related to the condition.

"These findings are important because many of the current conventional treatment strategies for atrial fibrillation include invasive procedures or medications with undesirable side effects," said Dr. Dhanunjaya Lakkireddy, an associate professor with the University of Kansas Hospital in Kansas City, Kansas, who led the study.

He presented his findings at the annual meeting of the American College of Cardiology being held in New Orleans.

The study involved 49 patients with the heart rhythm disorder who had no physical limitations and no prior experience with yoga. Their episodes of irregular heartbeat were measured for a six-month period by researchers at the hospital.

During the first three months, patients were allowed to participate in any physical activity they liked.

For the remaining three months, they underwent a supervised yoga program that involved breathing exercises, yoga postures, meditation and relaxation.

Forty-five minute yoga sessions with a certified professional were held three times each week, and patients were encouraged to practice daily yoga exercises at home.

Heart monitors measured episodes of irregular heartbeat throughout the trial, and patients completed short self-administered surveys to assess their levels of anxiety, depression and overall quality of life.

'SIGNIFICANT IMPACT'

On average, yoga cut episodes of the irregular heartbeat in half, while also significantly reducing depression and anxiety scores and improving scores in physical functioning, general health, vitality, social functioning and mental health, the researchers found.

"It appears yoga has a significant impact on helping to regulate patients' heartbeat and improves the overall quality of life," Lakkireddy said.

Atrial fibrillation causes blood to pool in the upper chambers of the heart, where it can clot and travel to the brain, causing strokes. Millions of patients with the condition take the blood thinner warfarin every day to lower the risk of such clots, and thereby prevent strokes.

Considering its low cost and benefits, Lakkireddy said yoga should be considered in overall treatment of atrial fibrillation and other heart rhythm problems.

But Lakkireddy cautioned that larger studies are needed to bear out the findings of his study, and that patients should continue with standard medical therapy.

"Based on my findings, one should not tell patients that yoga will fix everything and they can stop taking their anticoagulants. Yoga is strictly a supplement for everything else they are doing medically," he said.

A new wave of promising medicines to prevent such strokes is being developed by several drugmakers, one of which -- Xarelto being developed by Bayer and Johnson & Johnson -- will be highlighted at the heart meeting.

But the pills come with side effects, and are expected to cost thousands of dollars a year, when they reach the market.