Outcome of isolated congenital complete heart block diagnosed in utero.

Abstract

Objective-To establish identifiable prenatal factors in fetal heart block which might predict death in utero, the need for intervention, or the probability of pacemaker requirement. Setting-Tertiary referral unit for fetal echocardiography. Subjects-36 fetuses with congenital complete heart block and structurally normal hearts identified between 1980 and 1993. Methods-Maternal anti-Ro antibody status was documented. Prenatal variables examined included absolute heart (ventricular) rate, change in rate, and development of hydrops fetalis. Postnatally, heart rate, need for pacing, and the indications for pacing were detailed. Results-Of the total of 36 patients, there are 24 survivors; 11 are paced. Of those fetuses which died, two were electively aborted for severe hydrops, seven died in utero, two were immediate postnatal deaths, and one was an unrelated infant death. The trend was for the heart rate to decrease during fetal life and postnatally. Fetuses with deteriorating cardiac function did not always show the lowest heart rates. Bradycardia of less than 55 beats/min in early pregnancy or rapid decrease in heart rate prenatally were poor prognostic signs. Hydrops was also associated with bad outcome, 10 out of the 12 hydropic fetuses dying (83%). Of 10 fetuses presenting with a heart rate above 60/min, nine survived of whom three required pacing. Of seven presenting with heart rates of S0/min or less, only three survived and two of these required pacing. Of the two fetuses with negative maternal anti-Ro antibody status one died in utero and one required heart transplantation after pacemaker insertion. Conclusions-Isolated complete heart block identified in fetal life does not always have a good prognosis. An individual heart rate does not accurately predict the outcome in utero or the need for postnatal pacing. Regular, careful monitoring during pregnancy is required in order to optimise care and timing of any interventions.

Signs of first‐degree heart block occur in one‐third of fetuses of pregnant women with anti–SSA/Ro 52‐kd antibodies

“…CHB has been associated with substantial perinatal mortality (20-30%), and the majority of children born alive require a pacemaker at an early age (6,7,(13)(14)(15).…”

Bloqueo cardiaco fetal completo: Reporte de dos casos y revisión de la literatura

“…El bloqueo completo cardiaco congénito sin malformación asociada tiene como principal factor etiológico la presencia de inmunocomplejos contra ribonucleoproteínas llamadas La y Ro. El sistema de HLA-B8-DR3 y el endovirus humano 3 (ERV-3) son marcadores genéticos que predisponen a la aparición de otros inmunocomplejos que también podrían ser causantes de la enfermedad (8)(9)(10)(11)(12)(13).…”

“…Se postuló que el efecto podría iniciarse en el segundo y tercer trimestre de la vida intrauterina, sin embargo evidencia reciente muestra que el daño se iniciaría en etapa embrionaria (3,11). Un estudio histológico de corazones fetales entre 9 a 25 semanas, todos provenientes de madres con mesenquimopatías y anti Ro positivo tanto en la madre como en el feto, evidenció la presencia de inmunocomplejos en zonas intracelulares del sistema de conducción, a esa edad gestacional.…”

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

“…2,4,5 Prenatal monitoring of fetuses with CCHB remains a significant challenge. Fetuses with deteriorating cardiac function may not always exhibit the lowest heart rate, 6 and other ultrasonographic markers of poor cardiac output, including standard Doppler indices, can be unreliable in the face of substantial bradycardia. 7,8 The cerebroplacental Doppler ratio (CPR), defined as the ratio of the middle cerebral artery pulsatility index (MCA-PI) to the umbilical artery pulsatility index (UA-PI), is a measure of redistribution of cardiac output, and it is predictive of adverse perinatal outcome in growth-restricted fetuses where there is altered umbilical artery resistance and fetal hypoxia.…”