title: Results of radiofrequency ablation in children with tachycardia-induced cardiomyopathy.
abstract: OBJECTIVE
  Tachycardia-induced cardiomyopathy (TIC) is a rare but potentially curable cause of dilated cardiomyopathy. Data on radiofrequency ablation (RFA) for TIC is limited. The aim of this study is to present our experience with RFA in children with TIC, retrospectively.
  
  
  METHODS
  The medical records of patients with TIC and those underwent RFA between 2000-2011 were systematically reviewed. Demographics and echocardiographic features were recorded. Tachycardia-induced cardiomyopathy is defined as dilatation of the heart chambers or heart failure with chronic or very frequent cardiac arrhythmia. Diagnosis was confirmed with normalization of functions after sinus rhythm has been achieved.
  
  
  RESULTS
  A total of 12 patients with a mean age of 6.3±4.1 years (in utero-11.5 years) at diagnosis were enrolled in the study consisting of 7 patients with permanent junctional reciprocating tachycardia and 5 patients with focal atrial tachycardia. The mean pre-RFA left ventricular end-diastolic diameter and left ventricular ejection fraction (LVEF) values were 49.1±9.6 mm (32-66) and 40.8±13.4% (23-57%), respectively. One month after RFA, the mean LVEF value was 62±4.9% (52-69), with only 2 out of 12 patients' LVEF values were still lower than 58%. Tachycardia recurrence was observed in 4 patients, 3 of which had successful repeated RFA procedure. Overall, cure for arrhythmia was achieved in 11 patients (92%), while reversal of heart failure achieved in all patients. In 1 patient permanent complete AV block was developed after the procedure.
  
  
  CONCLUSIONS
  Treatment of tachycardia with RFA, particularly in patients with arrhythmia refractory to medical therapy, is a feasible and effective treatment option regardless of age.
authors.affiliation: Department of Pediatric Cardiology, Faculty of Medicine, İhsan Doğramacı Childrens Hospital, Hacettepe University; Ankara-Turkey. h_h_aykan@yahoo.com.
authors.forename: Hayrettin Hakan
authors.initials: HH
authors.lastname: Aykan
authors.forename: Tevfik
authors.initials: T
authors.lastname: Karagöz
authors.forename: Alper
authors.initials: A
authors.lastname: Akın
authors.forename: Ahmet
authors.initials: A
authors.lastname: İrdem
authors.forename: Sema
authors.initials: S
authors.lastname: Özer
authors.forename: Alpay
authors.initials: A
authors.lastname: Çeliker
mesh_terms: D002311:Cardiomyopathy, Dilated / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D017115:Catheter Ablation; D002648:Child; D002675:Child, Preschool; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D012189:Retrospective Studies; D013610:Tachycardia / Q000150:complications / Q000601:surgery*; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*