Finding the "PR-fect" solution: What is the best tool to measure fetal cardiac PR intervals for the detection and possible treatment of early conduction disease?

Colin K.L. Phoon, Mimi Y. Kim, Jill P. Buyon, Deborah M. Friedman

Research output: Contribution to journalReview article

14 Scopus citations


In the absence of structural heart disease, the great majority of cases with complete congenital heart block will be associated with the maternal autoantibodies directed to components of the SSA/Ro-SSB/La ribonucleoprotein complex. Usually presenting in fetal life before 26 weeks' gestation, once third-degree (complete) heart block develops, it is irreversible. Therefore, investigators over the past several years have attempted to predict which fetuses will be at risk for advanced conduction abnormalities by identifying a biomarker for less severe or incomplete disease, in this case, PR interval prolongation or first-degree atrioventricular block. In this state-of-the-art review, we critically analyze the various approaches to defining PR interval prolongation in the fetus, and then analyze several clinical trials that have attempted to address the question of whether complete heart block can be predicted and/or prevented. We find that, first and foremost, definitions of first-degree atrioventricular block vary but that the techniques themselves are all similarly valid and reliable. Nevertheless, the task of predicting those fetuses at risk, and who are therefore candidates for treatment, remains challenging. Of concern, despite anecdotal evidence, there is currently no conclusive proof that a prolonged PR interval predicts complete heart block.

Original languageEnglish (US)
Pages (from-to)349-360
Number of pages12
JournalCongenital Heart Disease
Issue number4
StatePublished - Jul 1 2012



  • Anti-La Antibodies
  • Anti-Ro Antibodies
  • Congenital Heart Block
  • Fetal Echocardiography
  • Maternal Autoimmune Disease
  • Neonatal Lupus

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health
  • Surgery
  • Radiology Nuclear Medicine and imaging
  • Cardiology and Cardiovascular Medicine

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