The prevalence of Wolff-Parkinson-White syndrome in newborns – results from a large general population study

Abstract Background The accessory electrical pathway in Wolff-Parkinson-White (WPW) syndrome predisposes to tachycardia and may increase risk of sudden cardiac death. Studies investigating the prevalence of this condition in newborns are few. Purpose To describe the prevalence of WPW syndrome and assess the localization of the accessory pathway and associated structural heart disease in newborns from a large general population study. Methods Electrocardiograms (ECG's) and echocardiograms of 17.489 newborns (aged 0–30 days) from a large, prospective general population study were included. WPW cases were identified through manual evaluation of outliers in measurements of PR-interval, QRS-duration, QTcB interval and QRS axis. Newborns suspected for WPW syndrome were offered a secondary echocardiogram and ECG recording. Localization of the accessory pathway was assessed based on a QRS polarity algorithm. The control group consisted of 5,000 randomly selected newborns with a normal echocardiogram. Results Among the 17,489 ECG's we manually analyzed 5,166 and found 15 newborns (80% boys) with WPW syndrome (secondary confirmatory ECG's will be available at ESC 2020) consistent with prevalence of WPW syndrome of 0.1%. The median values of the PR-interval, QRS-duration and QTcB in cases and controls were 80 vs 98 ms, 74 vs 56 ms, and 449 vs 420 ms, respectively (all p<0.0001). The accessory electrical pathway was left-sided in 13 (87%) of the newborns. One newborn had moderate mitral regurgitation while all other newborns had structurally normal hearts and no cases of Ebstein's anomaly. Conclusion The prevalence of WPW syndrome in our cohort was 0.1%. The syndrome was more frequent in boys, and the accessory pathways were mainly left-sided. All but one of the affected newborns had structurally normal hearts. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): This work was supported by the Danish Children Heart Foundation, Snedkermester Sophus Jacobsen and wife Astrid Jacobsen's foundation (Grant 19-R112-A5248-26048), the Research Council at Herlev-Gentofte Hospital and Toyota-Fonden, Denmark.