title: Assessment of Efficacy and Necessity of Routine Defibrillation Threshold Testing in Patients Undergoing Implantable Cardioverter-Defibrillator (ICD) Implantation.
abstract: Defibrillation threshold (DFT) testing is performed routinely in patients undergoing implantable cardioverter-defibrillator (ICD) implantation to verify the ability of the ICD to terminate ventricular fibrillation (VF). However, neither the efficacy nor the safety of DFT testing has been proven; thus, the necessity of such testing is controversial. We conducted a retrospective study of the efficacy of DFT testing, particularly with respect to long-term outcomes of ICD implantation.The study included 150 patients (125 men, 25 women, aged 59.0 ± 17.6 years) who underwent ICD or cardiac resynchronization therapy defibrillator implantation, with (n = 73) or without (n = 77) intraoperative DFT testing, between June 1996 and September 2007. VF was induced by delivery of a T-wave shock, and a 20-25-J shock was then delivered. If the 20-25-J shock failed to terminate VF, 30 J was delivered. We assessed whether undersensed VF events occurred during DFT testing and/or during patient follow-up and checked for any association between undersensing and delayed shock delivery. During DFT testing, fine VF was sensed, and shocks were delivered in a timely manner. Nevertheless, 2 patients in the DFT testing group died from VF within 3 years after device implantation.DFT testing, in comparison to non-DFT testing, appeared to have no influence on the long-term outcomes of our patients, suggesting that DFT testing at the time of ICD implantation is limited.
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine.
authors.forename: Sonoko
authors.initials: S
authors.lastname: Ashino
authors.forename: Toshiko
authors.initials: T
authors.lastname: Nakai
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Sonoda
authors.forename: Naoko
authors.initials: N
authors.lastname: Sasaki
authors.forename: Sayaka
authors.initials: S
authors.lastname: Kurokawa
authors.forename: Yukitoshi
authors.initials: Y
authors.lastname: Ikeya
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Okumura
authors.forename: Kimie
authors.initials: K
authors.lastname: Ohkubo
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kunimoto
authors.forename: Ichiro
authors.initials: I
authors.lastname: Watanabe
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hirayama
mesh_terms: D000328:Adult; D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000009:adverse effects / Q000379:methods; D017147:Defibrillators, Implantable / Q000009:adverse effects / Q000592:standards; D004554:Electric Countershock / Q000009:adverse effects / Q000379:methods; D019544:Equipment Failure Analysis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007430:Intraoperative Care / Q000379:methods; D007564:Japan; D008297:Male; D008422:Materials Testing / Q000379:methods*; D008875:Middle Aged; D010043:Outcome and Process Assessment, Health Care; D014693:Ventricular Fibrillation / Q000517:prevention & control*