First-Degree Fetal Heart Block May be Reversible

There is an increased risk of fetal heart problems when mothers carry particular antibodies associated with rheumatic diseases, according to an abstract presented by Yale School of Medicine researchers at the Society for Maternal-Fetal Medicine Conference February 9 in San Francisco.

Congenital heart block (CHB) is present at or before birth and impairs the heart’s electrical signaling from the upper to the lower chambers. CHB carries a 20 percent death rate and nearly all survivors require pacemakers. Joshua Copel, M.D., professor in the Department of Obstetrics, Gynecology & Reproductive Sciences at Yale helped conduct the PR Interval and Dexamethasone Evaluation (PRIDE) study with a team of other researchers to evaluate an early marker of cardiac injury before there is permanent scarring.

The PRIDE group conducted a longitudinal (observational) study following over 100 women with the anti-Ro and anti-La antibodies to determine if there were early signs of fetal heart problems. They also explored whether early treatment would reverse the problems.

The team found that while first-degree fetal heart block may be reversible with the steroid drug dexamethasone, the condition could advance within as little as one week to a third-degree block, which is irreversible even with further intervention.

“Given the high recurrence rate we confirmed in this study, close monitoring and the earliest possible marker is necessary,” said Copel, who plans trials of other possible treatments. “Advanced block and permanent heart damage can occur within one week of a normal echocardiogram, even a weekly evaluation may not be sufficient to detect early onset of disease.”

Other authors on the abstract include Jill Buyon of New York University, Deborah Friedman of St. Barnabas Hospital, and Mimi Kim of Albert Einstein Medical Center.

Abstract Title: “Prospective Cardiac Monitoring in Fetuses at Risk of Congenital Heart Block: The PR interval and Dexamethasone Evaluation (PRIDE) Study.”