The Wolff–Parkinson–White pattern is a delta wave frequently detected in school-based cardiovascular screening programs in Japan. Although most children with Wolff–Parkinson–White pattern are asymptomatic, initial symptoms may include syncope or sudden death, necessitating accurate diagnosis and management. Delta waves can also indicate a fasciculoventricular pathway, which poses no risk and does not require management.

We reviewed the medical records of patients referred to our hospital between April 2008 and March 2022 to evaluate the electrocardiographic signs of the Wolff–Parkinson–White pattern. The existence of Wolff–Parkinson–White syndrome and fasciculoventricular pathway were determined based on atrioventricular block and QRS waveform changes after adenosine administration during sinus rhythm.

The study cohort included 127 children (65 males; median age: 12.8 years, resting heart rate: 75 beats/min, PR interval: 109 ms, and QRS duration: 101 ms). The adenosine administration test revealed a fasciculoventricular pathway, Wolff–Parkinson–White syndrome, and indeterminate findings in 64, 54, and 9 children, respectively. More than 60% of children with a QRS duration ≤ 120 ms had a fasciculoventricular pathway. Age ≤ 12 years, QRS duration >120 ms, and type A category (children with R/S ratios >1 in lead V1) were identified as independent risk factors for Wolff–Parkinson–White syndrome. No adverse events were observed in any child.

The adenosine administration test is safe and feasible for differentiating Wolff–Parkinson–White syndrome from fasciculoventricular pathways and can reduce the unnecessary management of children with fasciculoventricular pathways.