January 19, 1999
A widely used nonsurgical treatment for rapid heart rhythms is safe and beneficial for both children and adults, according to results of a national study led by Johns Hopkins physicians.
"This is the first large multicenter study to suggest that radiofrequency catheter ablation is safe and effective therapy, and that it can now be considered as an alternative to drug therapy in the treatment of certain cardiac arrhythmias," says Hugh Calkins, M.D., lead author of the study and director of electrophysiology at Hopkins. "Before this procedure was developed in the early 1990s, arrhythmia patients were treated with medication, underwent open heart surgery or suffered. The technology has now advanced to the point at which we can do the procedure on an outpatient basis, curing patients within a matter of hours and sending them home the same day."
Radiofrequency catheter ablation destroys parts of the electrical pathways in the heart that cause rapid heart rhythms, or arrhythmias. A physician guides a catheter with an electrode at the tip to the focal point of the abnormal pathway in the heart muscle. Then a mild, painless burst of energy -- similar to microwave heat -- is transmitted to destroy the small area of heart tissue containing the pathway, ending the electrical misfirings that caused the arrhythmia.
Calkins estimates that more than 15,000 catheter ablations are performed nationwide each year. About one in every 100 people has some type of arrhythmia.
Results of the study were published in the Jan. 19 issue of Circulation, an American Heart Association journal.
Researchers followed 1,050 patients who underwent three types of catheter ablations between 1992 and 1995. The patient population consisted of 439 males and 561 females ranging in age from eight months to 90 years. Among the group, 133 (13 percent) were younger than 13 and 193 (18 percent) were between 13 and 20 years old. Underlying heart disease was present in 270 patients.
Results showed that catheter ablation could be performed with a high level of success (95 percent), a low recurrence rate (6 percent) and a relatively low incidence of major complications (3 percent). The one-year survival rate after catheter ablation was 98 percent.
In addition, the researchers noted that the probability for success was highest among medical centers that performed the greatest number of procedures on an annual basis.
Other institutions involved in the study were: Children's Hospital, Boston; Duke University Medical Center, Durham, N.C.; Good Samaritan Hospital, Los Angles; Krannert Institute, Indianapolis; Loyola University Medical Center, Maywood, Ill.; Mayo Clinic, Rochester, Minn.; Medical University of South Carolina, Charleston; Northside Cardiology, Indianapolis; St. Francis Hospital, Tulsa, Okla.; Sentara Norfolk General Hospital, Norfolk, Va.; Stanford University Medical Center, Stanford, Calif.; Sutter Memorial Hospital, Sacramento, Calif.; Temple University Medical Center, Philadelphia; University of Alabama at Birmingham; University Hospital of Cleveland; University of Massachusetts Medical Center, Worcester, Mass.; and Vanderbilt University Medical Center, Nashville, Tenn.