title: Catheter ablation of atrial tachyarrhythmias causing inappropriate implantable cardioverter-defibrillator shocks.
abstract: OBJECTIVE
  Inappropriate shocks have been an important issue post-implantable cardioverter-defibrillator (ICD) implantation. Moreover, inappropriate ICD shocks are associated with increased mortality. The objective of this study was to evaluate the feasibility of catheter ablation therapy for atrial tachyarrhythmias (ATa) responsible for inappropriate ICD shocks.
  
  
  RESULTS
  Among 108 consecutive patients who underwent ICD implantations, 22, 5, and 3 experienced inappropriate ICD shocks due to ATa, sinus tachycardia, and T-wave oversensing, respectively. Among the 22 patients with ATa, 18 patients (55 ± 10 years, 15 men, structural heart disease in 9) underwent catheter ablation of ATa causing inappropriate shocks. The median duration between the ICD implantation and first inappropriate shock was 10.0 (3.0-24.5) months. The ATa were atrial fibrillation (AF), atrial flutter (AFL), and atrioventricular nodal reentrant tachycardia in 14, 2, and 2 patients, respectively. One patient underwent an atrioventricular nodal ablation for persistent AF associated with a venous anomaly. Among 13 patients who underwent pulmonary vein antrum isolation, 10 (76.9%) were free from AF for a median of 21.0 (13-37.3) months after an average of 1.3 ± 0.5 procedures. In four patients with AFL or a supraventricular tachycardia, none had any arrhythmia recurrence for a median of 6.0 (3.3-93.5) months after a cavotricuspid isthmus or slow pathway ablation, respectively. There were no procedural complications. During the median follow-up of 19.0 (9.5-37.3) months after the last procedure, no patients experienced any inappropriate shocks.
  
  
  CONCLUSIONS
  Catheter ablation is a feasible therapeutic option for treating ATa responsible for inappropriate shock(s) in patients with ICD.
authors: Cardiology Division, Cardiovascular Center, Tsuchiura Kyodo Hospital, 11-7 Manabeshin-machi, Tsuchiura, Ibaraki 300-0053, Japan mshinsuke@k3.dion.ne.jp.
authors: Shinsuke
authors: S
authors: Miyazaki
authors: Cardiology Division, Cardiovascular Center, Tsuchiura Kyodo Hospital, 11-7 Manabeshin-machi, Tsuchiura, Ibaraki 300-0053, Japan.
authors: Hiroshi
authors: H
authors: Taniguchi
authors: Cardiology Division, Cardiovascular Center, Tsuchiura Kyodo Hospital, 11-7 Manabeshin-machi, Tsuchiura, Ibaraki 300-0053, Japan.
authors: Shigeki
authors: S
authors: Kusa
authors: Cardiology Division, Cardiovascular Center, Tsuchiura Kyodo Hospital, 11-7 Manabeshin-machi, Tsuchiura, Ibaraki 300-0053, Japan.
authors: Yuki
authors: Y
authors: Komatsu
authors: Cardiology Division, Cardiovascular Center, Tsuchiura Kyodo Hospital, 11-7 Manabeshin-machi, Tsuchiura, Ibaraki 300-0053, Japan.
authors: Noboru
authors: N
authors: Ichihara
authors: Cardiology Division, Cardiovascular Center, Tsuchiura Kyodo Hospital, 11-7 Manabeshin-machi, Tsuchiura, Ibaraki 300-0053, Japan.
authors: Takamitsu
authors: T
authors: Takagi
authors: Cardiology Division, Cardiovascular Center, Tsuchiura Kyodo Hospital, 11-7 Manabeshin-machi, Tsuchiura, Ibaraki 300-0053, Japan.
authors: Jin
authors: J
authors: Iwasawa
authors: Cardiology Division, Cardiovascular Center, Tsuchiura Kyodo Hospital, 11-7 Manabeshin-machi, Tsuchiura, Ibaraki 300-0053, Japan.
authors: Akio
authors: A
authors: Kuroi
authors: Cardiology Division, Cardiovascular Center, Tsuchiura Kyodo Hospital, 11-7 Manabeshin-machi, Tsuchiura, Ibaraki 300-0053, Japan.
authors: Hiroaki
authors: H
authors: Nakamura
authors: Cardiology Division, Cardiovascular Center, Tsuchiura Kyodo Hospital, 11-7 Manabeshin-machi, Tsuchiura, Ibaraki 300-0053, Japan.
authors: Hitoshi
authors: H
authors: Hachiya
authors: Heart Rhythm Center, Tokyo Medical and Dental University, Tokyo 113-8510, Japan.
authors: Kenzo
authors: K
authors: Hirao
authors: Cardiology Division, Cardiovascular Center, Tsuchiura Kyodo Hospital, 11-7 Manabeshin-machi, Tsuchiura, Ibaraki 300-0053, Japan.
authors: Yoshito
authors: Y
authors: Iesaka
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000601:surgery*; D001282:Atrial Flutter / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D004868:Equipment Failure; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000601:surgery*
keywords: Atrial tachyarrhythmias; Catheter ablation; Implantable cardioverter-defibrillator; Inappropriate shock