Electrophysiologic characteristics and catheter ablation results of tachycardia-induced cardiomyopathy in children with structurally normal heart

The aim of this study is to present electrophysiologic characteristics and catheter ablation results of tachycardia-induced cardiomyopathy (TIC) in children with structurally normal heart. We performed a single-center retrospective review of all pediatric patients with TIC, who underwent an electrophysiology study and ablation procedure in our clinic between November 2013 and January 2019. A total of 26 patients, 24 patients with single tachyarrhythmia substrates and two patients each with two tachyarrhythmia substrates, resulting with a total of 28 tachyarrhythmia substrates, underwent ablation for TIC. The median age was 60 months (2-214 months). Final diagnoses were supraventricular tachycardia (SVT) in 24 patients and ventricular tachycardia (VT) in two patients. The most common SVT mechanisms were focal atrial tachycardia (31%), atrioventricular reentrant tachycardia (27%), and permanent junctional reciprocating tachycardia (15%). Radiofrequency ablation (RFA) was performed in 15 tachyarrhythmia substrates, and cryoablation was performed in 13 tachyarrhythmia substrates, as the initial ablation method. Acute success in ablation was achieved in 24 out of 26 patients (92%). Tachycardia recurrence was observed in two patients (8%) on follow-up, who were treated successfully with repeated RFA later on. Overall success rates were 92% (24 out of 26) in patients and 93% (26 out of 28) in substrates. On echocardiography controls, the median left ventricular recovery time was 3 months (1-24 months), and median reversible remodeling time was 6 months (3-36 months). TIC should be kept in mind during differential diagnosis of dilated cardiomyopathy. Pediatric TIC patients can be treated successfully and safely with RFA or cryoablation. With an early diagnosis of TIC and quick restoration of the normal sinus rythm, left ventricular recovery, and remodeling may be facilitated.