In laboratory tests in dogs, cardiac researchers at Washington University School of Medicine in St. Louis have found that treatment with anti-inflammatory drugs after heart surgery may lessen or prevent atrial fibrillation. They report their findings in the June 7 issue of Circulation.

Atrial fibrillation--a rapid, irregular twitching of the upper chambers of the heart--occurs in a quarter to a half of patients who undergo heart surgeries such as coronary bypass or valve replacement. The condition can lead to serious post-operative complications, including congestive heart failure or stroke.

"Patients have suffered postoperative atrial fibrillation since the early days of cardiac surgery, and while beta-blockers--drugs used to prevent abnormal heart rhythms--seem to reduce the incidence, there has been no cure," says senior author Ralph Damiano Jr., M.D., the John Schoenberg Professor of Surgery and a cardiovascular specialist at Barnes-Jewish Hospital. "Our research suggests inflammation is the cause of postoperative atrial fibrillation, and this gives us new options for preventative therapy."

The researchers' investigated the effects of heart surgery in dogs. They found that the severity of atrial fibrillation corresponded to the amount of inflammation in surgically treated heart tissue. Inflammation led to changes in the electrical properties of the atria.

The inflammatory response consists of alterations in blood flow, increased permeability of blood vessels and escape of cells from the blood into the tissues. It is a normal response of tissue to injury that speeds the healing process in most instances.

"We found that inflammation led to non-uniform conduction of electrical impulses in the atria," Damiano says. "There were areas of very slow conduction and areas of
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Contact: Gwen Ericson
ericsong@wustl.edu
314-286-0141
Washington University School of Medicine
8-Jun-2005