Faculty Collaboration Database

Left Ventricular Isovolumetric Relaxation Time Is Prolonged in Fetal Long-QT Syndrome. Circ Arrhythm Electrophysiol 2018 Apr;11(4):e005797

Date

04/15/2018

Pubmed ID

29654130

DOI

10.1161/CIRCEP.117.005797

Scopus ID

2-s2.0-85053557569 (requires institutional sign-in at Scopus site)   32 Citations

Abstract

BACKGROUND: Long-QT syndrome (LQTS), an inherited cardiac repolarization disorder, is an important cause of fetal and neonatal mortality. Detecting LQTS prenatally is challenging. A fetal heart rate (FHR) less than third percentile for gestational age is specific for LQTS, but the sensitivity is only ≈50%. Left ventricular isovolumetric relaxation time (LVIRT) was evaluated as a potential diagnostic marker for fetal LQTS.

METHODS AND RESULTS: LV isovolumetric contraction time, LV ejection time, LVIRT, cycle length, and FHR were measured using pulsed Doppler waveforms in fetuses. Time intervals were expressed as percentages of cycle length, and the LV myocardial performance index was calculated. Single measurements were stratified by gestational age and compared between LQTS fetuses and controls. Receiver-operator curves were performed for FHR and normalized LVIRT (N-LVIRT). A linear mixed-effect model including multiple measurements was used to analyze trends in FHR, N-LVIRT, and LV myocardial performance index. There were 33 LQTS fetuses and 469 controls included. In LQTS fetuses, the LVIRT was prolonged in all gestational age groups (P<0.001), as was the N-LVIRT. The best cutoff to diagnose LQTS was N-LVIRT ≥11.3 at ≤20 weeks (92% sensitivity, 70% specificity). Simultaneous analysis of N-LVIRT and FHR improved the sensitivity and specificity for LQTS (area under the curve=0.96; 95% confidence interval, 0.82-1.00 at 21-30 weeks). N-LVIRT, LV myocardial performance index, and FHR trends differed significantly between LQTS fetuses and controls through gestation.

CONCLUSIONS: The LVIRT is prolonged in LQTS fetuses. Findings of a prolonged N-LVIRT and sinus bradycardia can improve the prenatal detection of fetal LQTS.

Author List

Clur SB, Vink AS, Etheridge SP, Robles de Medina PG, Rydberg A, Ackerman MJ, Wilde AA, Blom NA, Benson DW, Herberg U, Donofrio MT, Cuneo BF

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

Action Potentials
Colorado
Diastole
Echocardiography, Doppler, Pulsed
Electrocardiography
Female
Fetal Heart
Gestational Age
Heart Rate, Fetal
Humans
Long QT Syndrome
Netherlands
Predictive Value of Tests
Pregnancy
Reproducibility of Results
Retrospective Studies
Stroke Volume
Time Factors
Ultrasonography, Prenatal
Ventricular Function, Left