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To investigate the pediatric electrocardiographic characteristics of catecholaminergic polymorphic ventricular tachycardia (CPVT) in China.
A retrospective analysis of all electrocardiogram (ECG) data for 13 children(under 16 years old)with CPVT diagnosed in the Department of Cardiology, of Beijing Tsinghua Changgung Hospital and Peking University People's Hospital between September 2006 and March 2016.
(1) 9 were male (9/13, 69.2%) and the initial CPVT manifestations was syncope (12/13，92.3%) during 8.8±1.0 years old. The final diagnosis of CPVT was made in 11.6±2.5 years old. (2) 12-leads resting ECGs showed sinus bradycardia with resting heart rate 64.8±13.9 beats/min,furthermore 8-12 age group children had significantly lower heart rate than the normal population of the same age(58.6 beats/min vs.78 beats/min，p<0.05). QTc was normal as 428.3±18.3ms and T waves were with notch or bimodal in right chest leads(V1-V3) in six children. (3) Holter recorded bidirectional ventricular tachycardia / polymorphic VT /VF episodes in 5 patients, and supraventricular arrhythmia or/and sinus bradycardia were common. (4) Exercise-stress test showed ventricular arrhythmia occurring on stress stimulation, and premature ventricular contractions threshold was 124.5±23.2 beats/min, the morphology of CPVT was polymorphic and bidirectional(9/13,69.2%), bidirectional(4/13,30.7%). Meanwhile, atrial arrhythmia were recorded in 9 patients(9/13,69.2%) and premature atrial contractions(PACs)threshold was significantly lower than premature ventricular contractions(PVCs)(75.3±23.8 vs.110.1±15.8 beats/min, p<0.05). (5) One patient underwent electrophysiological examination, atrial tachycardia without ventricular arrhythmia was induced by electrophysiological stimulation, frequent bidirectional coupled PVCs were recorded after intravenous isoproterenol. And QTc prolongation occurred in only first sinus beat after program stimulation then subsequently returned to normal QTc (538.3 ± 22.0 vs.438.0 ± 1.5 ms, p <0.05).
ECG had important value in the diagnosis of CPVT in children.