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Isolated congenital atrioventricular block diagnosed in utero: natural history and outcome

Johannes M P J Breur1, Livia Kapusta, Philip Stoutenbeek

  • 1Department of Obstetrics, University Medical Center, Utrecht, the Netherlands. hans_breur@hotmail.com

The Journal of Maternal-Fetal & Neonatal Medicine : the Official Journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians
|June 24, 2008
PubMed

Insights

Congenital atrioventricular block (CAVB) diagnosed in utero has high mortality, especially with fetal hydrops or heart rates below 50 bpm. Poor outcomes, including pacemaker implantation or dilated cardiomyopathy, are linked to fetal heart rates below 60 bpm.

Area of Science:

  • Cardiology
  • Fetal Medicine
  • Pediatric Cardiology

Background:

  • Isolated congenital atrioventricular block (CAVB) diagnosed in utero presents significant morbidity and mortality risks.
  • Prognosis is particularly poor with fetal heart rates below 55 beats per minute (bpm) or the development of fetal hydrops.

Purpose of the Study:

  • To describe the natural history and outcomes of 24 infants with isolated CAVB diagnosed prenatally.
  • To review existing literature on CAVB.
  • To identify risk factors predicting outcomes in isolated CAVB.

Main Methods:

  • Retrospective multicenter study involving 24 patients diagnosed with isolated CAVB in utero.
  • Analysis of fetal heart rates, gestational age at diagnosis, development of fetal hydrops, and subsequent infant outcomes.

Main Results:

  • CAVB was detected at a mean gestational age of 24.7 weeks; 10 fetuses presented with complete heart block initially.
  • Fetal hydrops occurred in 42% of cases, associated with lower heart rates (47 bpm vs. 57 bpm).
  • Mortality was 21%, linked to heart rates <50 bpm and fetal hydrops; 83% experienced poor outcomes (death, pacemaker, or dilated cardiomyopathy) associated with heart rates <60 bpm.

Conclusions:

  • Isolated CAVB diagnosed in utero carries a high risk of morbidity and mortality.
  • Fetal hydrops and lower fetal heart rates (<50 bpm) are associated with increased mortality.
  • Fetal heart rates below 60 bpm predict the need for pacemaker implantation and/or the development of dilated cardiomyopathy.
Abstract

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