Light Exercise Prevents Atrial Fibrillation in Elderly (HealthDay)

TUESDAY, Aug. 5 (HealthDay News) -- Light to moderate exercise -- just walking a few blocks or even dancing -- can help prevent the abnormalheart rhythm called atrial fibrillation in those most vulnerable to it -- older people, a new study finds.

Atrial fibrillation, in which the two upper chambers of the heart tendto twitch rather than beat steadily, is the most common heart rhythmabnormality. It is especially common after age 65. The danger is thatblood can pool, causing clots that move to the heart or brain. There havebeen reports of an increased incidence of the abnormality in youngerpeople who exercise vigorously.

"Prior studies have looked at atrial fibrillation in young andmiddle-aged and generally healthy people," said study lead author Dr.Dariush Mozaffarian, a cardiologist at Brigham and Women's Hospital inBoston. "They found that, for example, marathon runners have a higher riskof atrial fibrillation. But the vast majority of atrial fibrillationoccurs later in life. After 65, about one in five people develops atrialfibrillation over 10 years."

Mozaffarian and his colleagues studied the habits of 5,446 adults,average age 73, comparing their physical activities with the risk ofdeveloping atrial fibrillation.

"No one has looked at exercise and atrial fibrillation in these olderpeople," he said. "We found that light to moderate exercise, such aswalking 10 blocks a week, was associated with a lower incidence of atrialfibrillation."

Specifically, the researchers found that the incidence of the heartabnormality was 22 percent lower in those walking five to 11 blocks a weekthan for those walking fewer than five blocks a week. It was 24 percentlower for those walking 12 to 23 blocks weekly, 33 percent lower for thosewalking 24 to 59 blocks, and 44 percent lower for those walking 60 or moreblocks a week.

Overall, there was a 50 percent lower risk of developing atrialfibrillation when comparing people with the highest and lowest levels ofwalking distance and pace.

The findings were published in the Aug. 5 issue of the journalCirculation.

Meanwhile, a separate trial looking at the effect of exercise on atrialfibrillation from a different angle is being done by Dr. Jose A. Joglar,an associate professor of internal medicine and director of clinicalcardiac physiology at the University of Texas Southwestern Medical Centerat Dallas.

"We have enrolled patients who have atrial fibrillation already to seewhether exercise improves their quality of life," Joglar said.

The 10 participants in the trial, all in their mid-70s and diagnosedwith atrial fibrillation, are doing aerobic exercises 45 minutes a day,three or four days a week, Joglar said. "They are riding stationarybicycles or walking fast," he explained.

The study is ongoing, but "preliminary data appears to be that theyfeel better and function better," Joglar said.

He and Mozaffarian stressed that light exercise, whatever its effect onatrial fibrillation, has known benefits, such as helping control bloodpressure and weight. Other studies have shown that the right exercise -- "not too strenuous but not too light, either" -- is helpful againstangina, the chest pain caused by heart artery problems, Joglar said.

"There are additional strong reasons for the public to focus onexercise," Mozaffarian said.

More information

The has more on atrialfibrillation and its treatment.