Sustained tachyarrhythmia in children younger than 1 year of age: Six year single-center experience.

Background: The aim of this study was to evaluate the results of non-operational sustained tachyarrhythmia in patients <1 year of age at the present center.
Methods: Between November 2010 and November 2016, the demographic characteristics, type and localization of the tachyarrhythmia, echocardiographic findings, and medical and/or ablation therapy for patients <1 year of age with sustained tachyarrhythmia were evaluated.
Results: Of 99 patients, 91 had sustained supraventricular tachycardia, and eight had sustained ventricular tachycardia. The median age was 30 days (range, 1-350 days), and the median weight was 4.2 kg (range, 2-13 kg). The common symptoms were palpitation and restlessness (n = 49, 49.5%), or the tachycardia was detected during routine inspection (n = 25, 25.3%) or fetal echocardiography (n = 11, 11.1%). Nineteen individuals (19%) had left ventricular (LV) dysfunction on first echocardiography. Twenty individuals had congenital heart disease. Common diagnoses were Wolff-Parkinson-White syndrome (n = 27), focal atrial tachycardia (n = 10), permanent junctional reciprocating tachycardia(n = 6), and atrial flutter (n = 6). Seventeen patients underwent medical therapy combined with cardioversion. The most commonly used abortive and acute therapy agents were adenosine, esmolol, and amiodarone. The most common combination therapy was propranolol and amiodarone, followed by a propranolol and propafenone combination. Nine individuals were treated with catheter ablation due to either resistance to medical therapy or LV dysfunction.
Conclusions: Tachyarrhythmias in children <1 year of age are mostly caused by accessory pathways and require multidrug therapy. Catheter ablation is an effective alternative therapy in the case of resistance to medical therapy and/or LV dysfunction.
(© 2017 Japan Pediatric Society.)