more prevalent at any age, experts say, because of a rise in three leading risk factors — high blood pressure, diabetes and obesity.
These conditions can damage the heart’s electrical system, Dr. Ruff wrote last year in the journal Circulation. Other risk factors include a prior heart attack, overactive thyroid, sleep apnea, excessive alcohol consumption, abnormal heart valves, lung disease and congenital heart defects.
Researchers at the University of California, San Francisco, reported this month in Annals of Internal Medicine that people with a high rate of premature atrial contractions, which can be detected by a Holter monitor worn for 24 hours, face a significantly increased risk of developing A-fib. Dr. Gregory M. Marcus, the senior author and director of clinical research at U.C.S.F.’s cardiology division, theorized that eradicating these premature contractions with drugs or a procedure that destroys the malfunctioning area of the heart may reduce the risk of the rhythm disorder.
Step 1 in treating A-fib is to identify and correct reversible risk factors. Step 2 — and most important, according to Dr. Ruff — is to prevent blood clots from forming by treating patients with anticoagulants.
The most commonly prescribed and least costly treatment is warfarin, also known by the brand name Coumadin, in use for more than half a century. But while highly effective at reducing the risk of stroke, warfarin is a very tricky drug. It interacts with a number of foods, especially those like spinach and kale that are rich in vitamin K, and other drugs that a patient may have to take.
People metabolise warfarin at different rates, making it necessary to repeatedly check a patient’s clotting ability to reduce the risk of excessive bleeding while maintaining an effective anticoagulant level.
Dr. Ruff said that more than half of A-fib patients were either not on an anticoagulant or on an ineffective dose. Fearful of a hemorrhage in the brain, or uncontrolled bleeding in an accident or emergency surgery, doctors may prescribe an amount of warfarin insufficient to prevent a stroke, he said.
Last year, Dr. Sanjiv Narayan, an electrophysiologist at the University of California, San Diego, and co-authors described a way to more accurately identify the electrical “hot spots” in the heart responsible for an abnormal rhythm. Ablating those regions was nearly twice as effective as the standard approach to eliminating atrial fibrillation with ablation, the team reported in The Journal of the American College of Cardiology.
But even when all