Faculty Collaboration Database

Electrophysiological characteristics of fetal atrioventricular block. J Am Coll Cardiol 2008 Jan 01;51(1):77-84

Date

01/05/2008

Pubmed ID

18174041

Pubmed Central ID

PMC3296565

DOI

10.1016/j.jacc.2007.06.060

Scopus ID

2-s2.0-37449029307 (requires institutional sign-in at Scopus site)   85 Citations

Abstract

OBJECTIVES: The purpose of our work was to define the complex electrophysiological characteristics seen in second- (2 degrees) and third-degree (3 degrees) atrioventricular block (AVB) and to longitudinally follow the development of atrial and ventricular heart rate and rhythm patterns with a goal of identifying heart rate and rhythm patterns associated with urgent delivery or neonatal pacing.

BACKGROUND: The electrophysiological characteristics of congenital AVB before birth have not been extensively studied, yet the mortality from this disease is substantial. Along with advances in fetal therapies and interventions, a comprehensive natural history specific to the etiology of AVB, as well as the electrophysiological factors influencing outcome, are needed to best select treatment options.

METHODS: Twenty-eight fetuses with AVB were evaluated by fetal magnetocardiography; 21 fetuses were evaluated serially.

RESULTS: Fetuses with 2 degrees AVB and isolated 3 degrees AVB showed: 1) diverse atrial rhythms and mechanisms of atrioventricular conduction during 2 degrees AVB; 2) junctional ectopic tachycardia and ventricular tachycardia during 3 degrees AVB; 3) reactive ventricular and atrial fetal heart rate (FHR) tracings at ventricular rates >56 beats/min; and 4) flat ventricular FHR tracings at ventricular rates <56 beats/min despite reactive atrial FHR tracings. In contrast, fetuses with 3 degrees AVB associated with structural cardiac disease exhibited predominantly nonreactive heart rate tracings and simpler rhythms.

CONCLUSIONS: Second-degree AVB, isolated 3 degrees AVB, and 3 degrees AVB associated with structural cardiac disease manifest distinctly different electrophysiological characteristics and outcome. Fetuses with 2 degrees AVB or isolated 3 degrees AVB commonly exhibited complex, changing heart rate and rhythm patterns; all 19 delivered fetuses are alive and healthy. Fetuses with structural cardiac disease and 3 degrees AVB exhibited largely monotonous heart rate and rhythm patterns and poor prognosis. Junctional ectopic tachycardia and/or ventricular tachycardia may be characteristic of an acute stage of heart block.

Author List

Zhao H, Cuneo BF, Strasburger JF, Huhta JC, Gotteiner NL, Wakai RT

Author

Janette F. Strasburger MD Professor in the Pediatrics department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Atrioventricular Block
Electrocardiography
Female
Fetal Diseases
Gestational Age
Heart Conduction System
Heart Rate, Fetal
Humans
Magnetocardiography
Male
Pregnancy
Prenatal Diagnosis
Retrospective Studies
Tachycardia, Ventricular