Drug, Pacemaker Fight Irregular Heartbeat

Studies suggest new weapons against dangerous atrial fibrillation.

By Ed Edelson
HealthDay Reporter
Wednesday, September 5, 2007; 12:00 AM

Copyright © 2007 ScoutNews, LLC. All rights reserved.

WEDNESDAY, Sept. 5 (HealthDay News) -- Cardiac researchers say a new drug may help treat the abnormal heartbeat called atrial fibrillation.

The drug, dronedarone, is not yet approved by the U.S. Food and Drug Administration but has proven effective in two major trials, with fewer side effects than existing medications, according to a report in the Sept. 6 issue of the New England Journal of Medicine.

And in the same issue of the journal, researchers say a special pacemaker can help prevent the development of atrial fibrillation in people with sinus-node disease -- a dysfunction of the cardiac region controlling heartbeat.

The American Heart Association estimates that 2.2 million Americans, many of them elderly, have atrial fibrillation, in which the two upper chambers of the heart lose their regular rhythm.

The condition increases the risk of dangerous clots forming as blood pools in the heart. Atrial fibrillation is treated with drugs that prevent clot formation and also with medications that restore the heart's normal rhythm.

The two trials -- which were funded by Sanofi-Aventis, the maker of dronedarone -- included more than 1,200 participants with atrial fibrillation.

In one European trial, the heartbeat remained normal for an average of 96 days in those getting dronedarone, compared to 41 days in those getting a placebo. In the other trial, conducted in the United States and several other countries, the heartbeat remained normal for an average of 158 days for those getting dronaderone and 59 days in those getting placebo.

Most important, the incidence of dangerous side effects -- such as occur with an approved drug, amiodarone -- was low in the dronedarone trial, said lead researcher Dr. Bramah N. Singh, a professor of medicine at the University of California at Los Angeles. Amiodarone can affect the thyroid, liver and lungs.

"Up to this time, there have been no cases of pulmonary fibrosis [associated with dronedarone], which is the most deadly complication that a patient can have," Singh noted.