Mayo Clinic Researchers Document Safer Treatment for Atrial Fibrillation

Friday, September 27, 2002

ROCHESTER, Minn. — The following stories detail news from the current issue of Mayo Clinic Proceedings. They are intended for use as individual stories or as part of a larger story on a particular medical topic.

Mayo Clinic researchers report that the risk of stroke that sometimes results from a common treatment for atrial fibrillation can be minimized when the patient takes anticoagulation medication prior to the procedure.

The researchers report on the largest single medical center experience regarding safety of elective direct current (DC) cardioversion of atrial fibrillation. DC cardioversion is the electronic restoration of the heart's normal rhythm.

Atrial fibrillation affects more than 2.5 million people in the United States. It is characterized by an irregular and rapid beating of the heart's atrial chambers and results when the normal electrical conduction system of the atria is not functioning properly. It is estimated that atrial fibrillation is responsible for more than 70,000 strokes each year in the United States. The prevalence of atrial fibrillation increases with age.

The researchers found that the rate of stroke or other embolic happenings — clots or blockages of the blood vessels — occurring in a patient after cardioversion was less than 1 percent. In the study, 834 successful cardioversions were performed in 717 patients from 1990 through 1994. Researchers said that use of adequate anticoagulation medication prior to the procedure reduced the risk of thromboembolism.

Mayo Clinic researchers involved in the study were Federico Gentile, M.D.; Bijoy Khanderia, M.D.; James Seward, M.D.; Christine Lohse, BSc; Win-Kuang Shen, M.D.; Kent Bailey, Ph.D.; Samantha Montgomery, MSc; Belli Burger, BSc and A. Jamil Tajik, M.D. Abdou Elhendy, M.D., Ph.D. is now with the University of Nebraska, Omaha.

Warren Manning, M.D., and Peter Zimetbaum, M.D., of Beth Israel Deaconess Medical Center in Boston, write in an accompanying editorial that clinicians must assess the individual patient to determine the benefits of cardioversion.

"If the decision favors cardioversion, (the researchers) have provided further proof of the efficacy of three to four weeks of warfarin anticoagulation before cardioversion," the editorialists write about the current approach to treatment.

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Contact:
John Murphy
507-284-5005 (days)
507-284-2511 (evenings)
e-mail: newsbureau@mayo.edu

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