The Deadly Irregular Heartbeat

No matter what other health problems a person has, a serious form of irregular heartbeat, called atrial fibrillation, increases the risk of death, especially for women, a study has confirmed.

People who have this type of arrhythmia often have additional heart problems, plus risk factors like smoking, diabetes, and high blood pressure. But until now, scientists had not known whether atrial fibrillation independently increases risk of death.

Researchers found that women with the heart-rhythm disturbance had a 90 percent higher risk of death than those without it. Men with the condition were 50 percent more likely to die.

An estimated 2 million Americans suffer from atrial fibrillation, the most common heart irregularity. It increases the risk of a blood clot breaking free and moving to the brain, causing a stroke, although blood thinners can significantly reduce that risk.

The study was published in Tuesday's edition of the American Heart Association journal Circulation. The lead author was Dr. Emelia J. Benjamin, Boston University School of Medicine associate professor of medicine and echocardiology director of the Framingham Heart Study.

In 40 years of follow-up to the Framingham study of 5,209 patients, atrial fibrillation developed in 325 women and 296 men. After 10 years, 57.8 percent of women ages 55 to 74 years with atrial fibrillation had died compared with 20.9 percent of women who did not have it.

In men, 61.5 percent of those with the condition died, compared with 30 percent without it. The researchers then adjusted their figures for other risk factors.