Congenital Complete Heart Block: Fetal Management Protocol, Review of the Literature, and Report of the Smallest Successful Pacemaker Implantation

Abstract

Fetuses with complete heart block have an increased mortality with most deaths occurring in utero or during infancy. The cardiac evaluation of these fetuses is difficult since the ventricular rate is low and the heart is dilated. We have implemented a strategy that includes the biophysical profile, which assesses fetal well-being, in combination with the cardiovascular profile that assesses cardiac function and the circulation. We present two cases of fetal complete heart block in which early delivery was recommended due to worsening cardiovascular profile scores. Biophysical profile scores were normal. Both babies were successfully treated, despite having risk factors that predicted poor outcomes. We hypothesize that our management protocol initiated intervention before fetal compromise, hydrops, and myocardial damage occurred. We recommend an evaluation of heart function in addition to an assessment of fetal well-being in fetuses with complete heart block. Early delivery should be considered if there is evidence of distress and/or deteriorating cardiac function.

A cardiovascular profile score in the surveillance of fetal hydrops

“…Therefore, a combined multivariate profile score, consisting of echocardiography, and arterial and venous Doppler variables, was used in the surveillance of hydropic fetuses. Previous published experience with the cardiovascular profile score (CVPS) in hydrops and in fetal heart block was in smaller series [7,8].…”

The cerebroplacental Doppler ratio predicts postnatal outcome in fetuses with congenital heart block

“…Fetal echocardiography has become the method of choice for detection, analysis and follow-up of fetal arrhythmias; however, prenatal monitoring of fetuses with CCHB remains a significant challenge. 3,7,8,13,14 Huhta 15 proposed a cardiovascular profile score based on fetal echocardiographic characteristics as a method for evaluation of a fetus with suspected congestive heart failure of any etiology. Donofrio et al 14 incorporated a fetal management protocol that used Huhta's cardiovascular profile score along with the biophysical profile to monitor fetal well-being in two fetuses with autoimmune-mediated CCHB.…”

Congenital complete heart block and maternal connective tissue disease

“…[50]. Early delivery should be considered if there is evidence of fetal distress or compromised ventricular function [51]. There is a high likelihood of delivery by caesarian section due to the inability to monitor fetal well being during labor by fetal heart rate.…”