title: Impact of pulmonary valve replacement on arrhythmia propensity late after repair of tetralogy of Fallot.
abstract: BACKGROUND
  Chronic pulmonary regurgitation after repair of tetralogy of Fallot (TOF) may lead to right ventricular dilatation, which may be accompanied by ventricular tachycardia and sudden death. We aimed to examine the effects of pulmonary valve replacement (PVR) on (1) certain electrocardiographic markers predictive of monomorphic ventricular arrhythmia and sudden death and (2) sustained atrial flutter/fibrillation and monomorphic ventricular tachycardia.
  
  
  RESULTS
  We studied 70 patients who underwent PVR for pulmonary regurgitation and/or right ventricular outflow tract obstruction late after repair of TOF. Maximum QRS duration and QT dispersion were measured from standard ECGs before PVR and at the latest follow-up. Arrhythmia was defined as sustained atrial flutter/fibrillation or sustained monomorphic ventricular tachycardia. Concomitant intraoperative electrophysiological mapping and/or cryoablation were performed in 9 patients (60%) with preexisting ventricular tachycardia and 6 patients (50%) with preexisting atrial flutter. QRS duration remained unchanged in the study group (P=0.46), but it was significantly prolonged (P<0.001) in a comparable group of patients with repaired TOF who did not undergo PVR. At a mean follow-up of 4.7 years, the incidence of ventricular tachycardia diminished from 22% to 9% (P<0.001), and atrial flutter/fibrillation decreased from 17% to 12% (P=0.32). Intraoperative ablation prevented recurrence of preexisting tachyarrhythmia (0 of 15 patients).
  
  
  CONCLUSIONS
  PVR in patients with previous TOF repair and chronic pulmonary regurgitation leads to stabilization of QRS duration and, in conjunction with intraoperative cryoablation, to a decrease in the incidence of preexisting atrial and ventricular tachyarrhythmia. When applicable, this combined approach should be used in patients late after repair of TOF.
authors.affiliation: University of Toronto Congenital Cardiac Center for Adults, Toronto, Ontario, Canada. judiththerrien@hotmail.com
authors.forename: J
authors.initials: J
authors.lastname: Therrien
authors.forename: S C
authors.initials: SC
authors.lastname: Siu
authors.forename: L
authors.initials: L
authors.lastname: Harris
authors.forename: A
authors.initials: A
authors.lastname: Dore
authors.forename: K
authors.initials: K
authors.lastname: Niwa
authors.forename: J
authors.initials: J
authors.lastname: Janousek
authors.forename: W G
authors.initials: WG
authors.lastname: Williams
authors.forename: G
authors.initials: G
authors.lastname: Webb
authors.forename: M A
authors.initials: MA
authors.lastname: Gatzoulis
mesh_terms: D000293:Adolescent; D000328:Adult; D001145:Arrhythmias, Cardiac / Q000209:etiology / Q000503:physiopathology*; D001282:Atrial Flutter / Q000209:etiology / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D019918:Heart Valve Prosthesis Implantation; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D011665:Pulmonary Valve Insufficiency / Q000601:surgery*; D016019:Survival Analysis; D017180:Tachycardia, Ventricular / Q000209:etiology / Q000503:physiopathology; D013771:Tetralogy of Fallot / Q000601:surgery*; D013997:Time Factors