title: Implantable cardioverter defibrillator utilization among device recipients presenting exclusively with syncope or near-syncope.
abstract: BACKGROUND
  Implantable cardioverter defibrillators (ICDs) are occasionally used in presumed high-risk patients with electrocardiographically undocumented syncope, although the incidence of ventricular tachyarrhythmias in this population is not well defined.
  
  
  RESULTS
  We studied 33 consecutive patients receiving an ICD (67% nonthoracotomy and 70% tiered therapy) after electrophysiologic testing for unmonitored "syncope" (n = 29) or "near-syncope" (n = 4). Atherosclerotic heart disease was present in 24 (73%); mean left ventricular ejection fraction (LVEF) was 0.39 +/- 0.15; and sustained monomorphic ventricular tachycardia (SMVT) was inducible in 18 (55%). Over a median follow-up of 17 months (range 4 to 61), 12 patients (36%) received > or = 1 appropriate ICD discharge triggered by SMVT (cycle length 230 to 375 msec) in 10 and ventricular flutter or fibrillation in 2--without concomitant antiarrhythmic medication in 8 of 12 cases. Inducible SMVT and LVEF < or = 0.35 were statistically significant, independent predictors of an appropriate ICD discharge (P < 0.02 and P < 0.03, respectively). Estimated 1-year cumulative survival free of appropriate discharge was 34% versus 87%, respectively, in patients with versus without inducible SMVT (P < 0.02), and 18% versus 56%, respectively, in patients with LVEF < or = 0.35 versus LVEF > 0.35 (P < 0.03).
  
  
  CONCLUSIONS
  In this highly select, multicenter population of ICD recipients with electrocardiographically undocumented syncope, a substantial incidence of appropriate device discharges was observed, particularly in patients with inducible SMVT and LVEF < or = 0.35. These findings support the notion that, in patients with LV dysfunction and inducible SMVT, ventricular tachyarrhythmias are likely to account for episodes of syncope or near-syncope.
authors.affiliation: The Arrhythmia Center/Sinai Hospital and St. John Hospital, Detroit, Michigan 48235, USA.
authors.forename: A
authors.initials: A
authors.lastname: Militianu
authors.forename: A
authors.initials: A
authors.lastname: Salacata
authors.forename: K
authors.initials: K
authors.lastname: Seibert
authors.forename: R
authors.initials: R
authors.lastname: Kehoe
authors.forename: J J
authors.initials: JJ
authors.lastname: Baga
authors.forename: M D
authors.initials: MD
authors.lastname: Meissner
authors.forename: L A
authors.initials: LA
authors.lastname: Pires
authors.forename: C D
authors.initials: CD
authors.lastname: Schuger
authors.forename: R T
authors.initials: RT
authors.lastname: Steinman
authors.forename: R D
authors.initials: RD
authors.lastname: Mosteller
authors.forename: A J
authors.initials: AJ
authors.lastname: Palti
authors.forename: J B
authors.initials: JB
authors.lastname: David
authors.forename: T J
authors.initials: TJ
authors.lastname: Lessmeier
authors.forename: M H
authors.initials: MH
authors.lastname: Lehmann
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003625:Data Collection; D017147:Defibrillators, Implantable; D004554:Electric Countershock / Q000295:instrumentation*; D004599:Electric Stimulation Therapy; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006334:Heart Function Tests; D006801:Humans; D008297:Male; D008875:Middle Aged; D016019:Survival Analysis; D013575:Syncope / Q000628:therapy*