An irregular heartbeat that doesn't respond to drugs can be effectively treated with heat-producing radio waves that destroy some heart tissue, researchers said.
The procedure uses a tiny catheter that's threaded through a blood vessel into the heart, where it produces 131 degrees of heat that, in effect, becomes a scalpel. A doctor then uses the heat to remove tissue near the left atrium, which generates erratic electrical impulses that lead to the heartbeat disorder known as chronic atrial fibrillation.
One year after treatment, 74 percent of the 77 patients who received the 90-minute procedure, called catheter ablation, had a normal heartbeat, according to a study in today's New England Journal of Medicine. Only 4 percent of 69 patients given the normal treatment of drugs and a shock to the heart to restore rhythm with no other therapy were free of symptoms a year later.
The surgery ''works in an effective and clinically meaningful way," said the lead researcher, Dr. Hakan Oral, an associate professor of medicine at the University of Michigan Medical School, in Ann
The journal report was published a day after Pittsburgh Penguins owner Mario Lemieux, who retired from playing last month because of the condition, returned home after undergoing the surgery, team officials have said.
Atrial fibrillation erodes quality of life and boosts risks of heart failure, stroke, and death.
After the surgery, hearts enlarged by the condition returned to normal size, and pumping power improved significantly, the study found. One in four patients needed a second catheter ablation, and 4 percent developed atrial flutter, another heart-rhythm abnormality.
Further research is needed to see how long the heart remains normal, Oral said, and whether the treatment results in patients living longer.
It's too soon to recommend catheter ablation for all patients with chronic atrial fibrillation, wrote Mark A. Wood and Kenneth A. Ellenbogen from Virginia Commonwealth University Medical Center, in an editorial that accompanied the study.