Prenatal Detection of Wolff-Parkinson-White Syndrome Using the Atrioventricular Interval on Fetal Echocardiogram

Fetal Doppler echocardiography has been widely used for the detection and characterization of fetal tachyarrhythmias. Doppler interrogation of the superior vena cava and the aorta (SVC-Ao) is used to determine the electrophysiological etiology of arrhythmias. The present study aims to investigate if the SVC-Ao technique in fetal echocardiograms could identify fetuses with Wolff-Parkinson-White (WPW) syndrome.

We retrospectively searched for consecutive fetal echocardiograms with evidence of tachyarrhythmias performed at the CHU Sainte-Justine from January 2000 to July 2021. The primary outcome was defined as the presence of pre-excitation on postnatal electrocardiogram (ECG) in the context of a prenatal tachyarrhythmia and the identification of a short atrioventricular (AV) interval.

From a cohort of 69 patients presenting with fetal tachyarrhythmia diagnosed by echocardiography, AV intervals were measured in 9 fetuses (13%) that showed WPW on the postnatal surface ECG. The AV interval measured using fetal echocardiography showed a median of 107 ms (interquartile range: 104-116 ms), representing a z-score of -1.27 (-2.01 to -0.56). Six fetuses (67%) had repeated AV intervals ≤-2 standard deviation. Three (33%) had WPW on postnatal surface ECG but did not have short AV intervals on fetal echocardiograms, representing a false negative for the diagnostic yield of the technique.

Doppler echocardiographic AV interval measurements in fetuses with arrhythmias allow identification of prenatal WPW. The early diagnosis of WPW offers the possibility of a more comprehensive postnatal management plan, including the neonatology and cardiology teams, as well as preparing in advance for specific antiarrhythmic drug therapy.