title: Inappropriate discharges by fourth generation implantable cardioverter defibrillators in patients with ventricular arrhythmias.
abstract: The study prospectively investigated the incidence, cause and efficient management of inappropriate discharge by the fourth generation implantable cardioverter-defibrillator (ICD) system in 45 patients (mean age, 57+/-16 years). During the follow-up period of 27+/-17 months, 18 patients (40%) experienced one or more inappropriate therapies: sinus and supraventricular tachycardia (15 patients) and T wave oversensing (3 patients). In the 15 patients, re-programming of the tachycardia detection interval and/or additional treatment with beta-blocking agents were effective. In the 3 patients with T wave oversensing, the arrythmia was associated with an increase in T wave amplitude, change in T wave morphology and decreased R wave amplitude, and re-programming of the sensitivity of the local electrogram or changing the number of intervals to detect ventricular tachycardia decreased the number of inappropriate discharges in all 3 patients. In conclusion, inappropriate therapies are common problems in patients treated with the fourth generation ICD system, but most of them can be resolved using the dual-chamber ICD system. However, in patients with T-wave oversensing, it is difficult to avoid inappropriate discharge completely, even if the dual-chamber ICD system is implanted.
authors.affiliation: First Department of Internal Medicine, Niigata University School of Medicine, Japan. washi@med.niigata-u.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Washizuka
authors.forename: M
authors.initials: M
authors.lastname: Chinushi
authors.forename: M
authors.initials: M
authors.lastname: Tagawa
authors.forename: H
authors.initials: H
authors.lastname: Kasai
authors.forename: H
authors.initials: H
authors.lastname: Watanabe
authors.forename: Y
authors.initials: Y
authors.lastname: Hosaka
authors.forename: F
authors.initials: F
authors.lastname: Yamashita
authors.forename: H
authors.initials: H
authors.lastname: Furushima
authors.forename: A
authors.initials: A
authors.lastname: Abe
authors.forename: H
authors.initials: H
authors.lastname: Watanabe
authors.forename: J
authors.initials: J
authors.lastname: Hayashi
authors.forename: Y
authors.initials: Y
authors.lastname: Aizawa
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000465:Algorithms; D002648:Child; D002675:Child, Preschool; D017147:Defibrillators, Implantable / Q000592:standards*; D022062:Electrophysiologic Techniques, Cardiac / Q000295:instrumentation / Q000592:standards; D004867:Equipment Design; D004868:Equipment Failure; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013616:Tachycardia, Sinus / Q000175:diagnosis / Q000628:therapy; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000628:therapy