Special electrophysiological characteristics of pediatric idiopathic ventricular tachycardia.
BACKGROUND
Idiopathic ventricular tachycardia (VT) is an important pediatric arrhythmia but relevant studies in Asian cohort are rare. We determined the electrophysiological characteristics and outcomes of this rhythm disturbance.


METHODS
From an institutional database, patients aged <18years without structural heart disease who have sustained monomorphic VT (longer than 30s) during 1995-2016 were enrolled.


RESULTS
We enrolled 57 idiopathic VT patients (male:female=31:26). The initial presentation included palpitation (64.9%) and shock (12.3%). The electrocardiography revealed relatively short QRS duration (123±18ms) and absence of ventriculoatrial dissociation in 33.3% of the patients, causing initial misdiagnosis in 29.8% of these patients. Patients with a VT onset age of <10years were more likely to have a left bundle branch block morphology (52.2% vs. 11.8%, p=0.001) and spontaneous recovery than those with a VT onset age of ≥10years. An electrophysiology study in 44 patients revealed that the most common arrhythmia focus was the left ventricular septal area (78%), called fascicular VT. Radiofrequency ablation showed a satisfactory success rate (90%) and fair recurrence rate (14.3%). Tachycardia-induced cardiomyopathy was noted in 14% of the VT patients and cardiac function returned to normal in 1-18months (median, 3months) after successful ablation.


CONCLUSIONS
In an Asian pediatric population, VT has distinct electrophysiological characteristics including dominant left ventricular origin, narrower QRS duration, and more symptomatic presentation. Transcatheter ablation is effective against VT, and the associated cardiomyopathy often resolves rapidly after successful ablation.
Department of Pediatrics, National Taiwan University Hospital and National Taiwan University Children Hospital, Taipei, Taiwan.
Shuenn-Nan
SN
Chiu
Department of Pediatrics, National Taiwan University Hospital and National Taiwan University Children Hospital, Taipei, Taiwan.
Wei-Lun
WL
Wu
Department of Pediatrics, National Taiwan University Hospital and National Taiwan University Children Hospital, Taipei, Taiwan.
Chun-Wei
CW
Lu
Department of Pediatrics, Changhua Christian Hospital, Changhua, Taiwan.
Kun-Lang
KL
Wu
Department of Pediatrics, National Taiwan University Hospital and National Taiwan University Children Hospital, Taipei, Taiwan.
Wei-Chieh
WC
Tseng
Department of Pediatrics, National Taiwan University Hospital and National Taiwan University Children Hospital, Taipei, Taiwan.
Ming-Tai
MT
Lin
Department of Pediatrics, Min-Sheng General Hospital, Taoyuan, Taiwan.
Chien-Chih
CC
Chang
Department of Pediatrics, National Taiwan University Hospital and National Taiwan University Children Hospital, Taipei, Taiwan.
Jou-Kou
JK
Wang
Department of Pediatrics, National Taiwan University Hospital and National Taiwan University Children Hospital, Taipei, Taiwan. Electronic address: wumh@ntuh.gov.tw.
Mei-Hwan
MH
Wu
D000293:Adolescent; D006328:Cardiac Catheterization / Q000639:trends; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004562:Electrocardiography / Q000639:trends*; D055724:Electrophysiological Phenomena / Q000502:physiology*; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology; D006801:Humans; D008297:Male; D017180:Tachycardia, Ventricular / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000503:physiopathology*; D013624:Taiwan / Q000453:epidemiology; D055815:Young Adult
Ablation; Asian; Left Purkinje; Pediatric; Ventricular tachycardia