Faculty Collaboration Database

In utero diagnosis of long QT syndrome by magnetocardiography. Circulation 2013 Nov 12;128(20):2183-91

Date

11/13/2013

Pubmed ID

24218437

Pubmed Central ID

PMC3831174

DOI

10.1161/CIRCULATIONAHA.113.004840

Scopus ID

2-s2.0-84887577555 (requires institutional sign-in at Scopus site)   93 Citations

Abstract

BACKGROUND: The electrophysiology of long QT syndrome (LQTS) in utero is virtually unstudied. Our goal here was to evaluate the efficacy of fetal magnetocardiography (fMCG) for diagnosis and prognosis of fetuses at risk of LQTS.

METHODS AND RESULTS: We reviewed the pre/postnatal medical records of 30 fetuses referred for fMCG because of a family history of LQTS (n=17); neonatal/childhood sudden cardiac death (n=3), or presentation of prenatal LQTS rhythms (n=12): 2° atrioventricular block, ventricular tachycardia, heart rate < 3(rd) percentile. We evaluated heart rate and reactivity, cardiac time intervals, T-wave characteristics, and initiation/termination of Torsade de Pointes, and compared these with neonatal ECG findings. After birth, subjects were tested for LQTS mutations. Based on accepted clinical criteria, 21 subjects (70%; 9 KCNQ1, 5 KCNH2, 2 SCN5A, 2 other, 3 untested) had LQTS. Using a threshold of corrected QT= 490 ms, fMCG accurately identified LQTS fetuses with 89% (24/27) sensitivity and 89% (8/9) specificity in 36 sessions. Four fetuses (2 KCNH2 and 2 SCN5A), all with corrected QT ≥ 620 ms, had frequent episodes of Torsade de Pointes, which were present 22-79% of the time. Although some episodes initiated with a long-short sequence, most initiations showed QRS aberrancy and a notable lack of pause dependency. T-wave alternans was strongly associated with severe LQTS phenotype.

CONCLUSIONS: Corrected QT prolongation (≥490 ms) assessed by fMCG accurately identified LQTS in utero; extreme corrected QT prolongation (≥620 ms) predicted Torsade de Pointes. FMCG can play a critical role in the diagnosis and management of fetuses at risk of LQTS.

Author List

Cuneo BF, Strasburger JF, Yu S, Horigome H, Hosono T, Kandori A, 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

Anti-Arrhythmia Agents
Cohort Studies
Electrocardiography
Female
Fetal Diseases
Genetic Association Studies
Heart Rate, Fetal
Humans
Infant, Newborn
Lidocaine
Long QT Syndrome
Magnetocardiography
Male
Pregnancy
Prenatal Diagnosis
Refractory Period, Electrophysiological
Retrospective Studies
Sensitivity and Specificity
Torsades de Pointes