title: Safety of antitachycardia pacing in patients with implantable cardioverter defibrillators and severely depressed left ventricular function.
abstract: The purpose of this study was to investigate the efficacy and safety of antitachycardia pacing (ATP) in third-generation implantable cardioverter defibrillators (ICDs) for terminating spontaneously occurring ventricular tachycardias (VTs) in patients with severely depressed left ventricular (LV) function. Ninety-one patients with active ATP were followed for 16 +/- 13 months. During this period, 775 VT episodes occurring in 36 patients were treated by ATP. The patients were divided into two groups according to their LV ejection fraction (LVEF): group A with LVEF < or = 30% (n = 20), and group B with LVEF > 30% (n = 16). There were no differences between both groups in age, gender, underlying heart disease, indication for ICD therapy, or drug therapy. The VT rates were comparable (group A: 183 +/- 16 beats/min; group B: 180 +/- 21 beats/min; P = NS). Eighty-three percent of all episodes (n = 332) in group A and 93% of the VTs (n = 443) in group B were ATP terminated (P < 0.01). Ten percent of VTs in group A were accelerated by ATP into the ventricular fibrillation zone versus 2% in group B (P < 0.01). The individual termination rate and acceleration rate per patient were comparable in both groups. All VT episodes unresponsive to ATP were converted by backup shocks. The efficacy of first-shock therapy was similar in both groups (group A: 89%; group B: 97%; P = NS). The proportion of patients who needed at least one backup shock for unsuccessful ATP was comparable in both groups (group A: 65%; group B: 56%; P = NS).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Universitätskliniken des Saarlandes, Homburg/Saar, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Heisel
authors.forename: J
authors.initials: J
authors.lastname: Neuzner
authors.forename: E
authors.initials: E
authors.lastname: Himmrich
authors.forename: H F
authors.initials: HF
authors.lastname: Pitschner
authors.forename: A
authors.initials: A
authors.lastname: Liebrich
authors.forename: J
authors.initials: J
authors.lastname: Jung
authors.forename: S
authors.initials: S
authors.lastname: Sen
mesh_terms: D017147:Defibrillators, Implantable; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D012189:Retrospective Studies; D013318:Stroke Volume / Q000502:physiology; D017180:Tachycardia, Ventricular / Q000453:epidemiology / Q000503:physiopathology / Q000628:therapy*; D013997:Time Factors; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology*; D016277:Ventricular Function, Left / Q000502:physiology