title: Mechanism and outcomes of catheter ablation for ventricular tachycardia in adults with repaired congenital heart disease.
abstract: Repaired congenital heart disease (rCHD) is strongly associated with ventricular tachycardia (VT) as an important late cause of morbidity and mortality. Ventricular reentry most commonly includes anatomic isthmuses created during the repair procedures.
  
  
  
  The purpose of this study was to analyze the long-term outcomes of catheter ablation, a commonly used standalone or adjunctive therapy, in a cohort of rCHD patients.
  
  
  
  A retrospective analysis of 21 consecutive patients with rCHD (45.0 ± 3.0 years, 71.4% male) undergoing ablation for VT was performed. The primary composite outcome was defined as in-hospital arrhythmic death, out-of-hospital sudden cardiac death, or appropriate implantable cardioverter-defibrillator therapy.
  
  
  
  At initial electrophysiologic study, 14 patients (66.7%) had reentrant VT through an electroanatomic isthmus; the remaining 7 patients (33.3%) demonstrated focal VT. Isthmus-dependent reentry was identified as the mechanism for VT in 14 patients (66.7%), and conduction block was confirmed in 8 of these patients (57.1%). No patients with confirmed block developed VT recurrence. During long-term follow-up (33 ± 7 months), 20 of 21 patients (95.2%) had not reached the primary composite outcome. Three patients died of nonarrhythmic causes.
  
  
  
  Catheter-based VT ablation in patients with rCHD is associated with a low rate of VT recurrence. Focal VT was not uncommon in this cohort. If a reentrant mechanism is present, confirmation of conduction block across the isthmus is vital to prevent recurrence.
authors.affiliation: Heart Rhythm Services, Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Martin
authors.initials: M
authors.lastname: van Zyl
authors.affiliation: Heart Rhythm Services, Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Suraj
authors.initials: S
authors.lastname: Kapa
authors.affiliation: Heart Rhythm Services, Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Deepak
authors.initials: D
authors.lastname: Padmanabhan
authors.affiliation: Department of Cardiology, Kettering Medical Center, Kettering, Ohio.
authors.forename: Frank C
authors.initials: FC
authors.lastname: Chen
authors.affiliation: Heart Rhythm Services, Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Siva K
authors.initials: SK
authors.lastname: Mulpuru
authors.affiliation: Heart Rhythm Services, Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Packer
authors.affiliation: Heart Rhythm Services, Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Munger
authors.affiliation: Heart Rhythm Services, Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Samuel J
authors.initials: SJ
authors.lastname: Asirvatham
authors.affiliation: Heart Rhythm Services, Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota. Electronic address: mcleod.christopher@mayo.edu.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: McLeod
mesh_terms: D000328:Adult; D017115:Catheter Ablation / Q000009:adverse effects / Q000379:methods; D016757:Death, Sudden, Cardiac / Q000517:prevention & control*; D017147:Defibrillators, Implantable / Q000706:statistics & numerical data; D004562:Electrocardiography / Q000379:methods; D005260:Female; D006330:Heart Defects, Congenital / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010043:Outcome and Process Assessment, Health Care; D011183:Postoperative Complications / Q000175:diagnosis / Q000601:surgery; D012008:Recurrence; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000209:etiology / Q000601:surgery; D014481:United States / Q000453:epidemiology
keywords: Adult congenital heart disease; Cardiac electrophysiology; Catheter ablation; Ventricular arrhythmia; Ventricular tachycardia