title: Rapid-rate nonsustained ventricular tachycardia found on implantable cardioverter-defibrillator interrogation: relationship to outcomes in the SCD-HeFT (Sudden Cardiac Death in Heart Failure Trial).
abstract: OBJECTIVE
  The aim of this study was to examine rapid-rate nonsustained ventricular tachycardia (RR-NSVT) during routine implantable cardioverter-defibrillator (ICD) evaluation in patients with heart failure and its relationship to outcomes.
  
  
  BACKGROUND
  The clinical implications of RR-NSVT identified during routine ICD interrogation are unclear. In this study, the occurrence of RR-NSVT and its association with ICD shocks and mortality in SCD-HeFT (Sudden Cardiac Death in Heart Failure Trial) were examined.
  
  
  METHODS
  The 811 patients who received ICDs in SCD-HeFT constituted the study population. The occurrence of RR-NSVT and its association with ICD shocks and mortality in SCD-HeFT were examined.
  
  
  RESULTS
  RR-NSVT was documented on ICD interrogation in 186 of 811 patients (22.9%). The mean duration of RR-NSVT was 26.4 ± 9.1 beats (7.5 ± 2.6 s), with a mean cycle length of 259 ± 32 ms. Polymorphic RR-NSVT accounted for 56% of episodes. Compared with patients without RR-NSVT, those with RR-NSVT were less likely to be taking beta-blockers, statins, or aspirin at enrollment. After adjusting for other known predictors of mortality in SCD-HeFT, RR-NSVT was independently associated with appropriate ICD shocks (hazard ratio: 4.25; 95% confidence interval: 2.94 to 6.14; p < 0.0001), with all-cause mortality (hazard ratio: 2.40; 95% confidence interval: 1.62 to 3.54; p < 0.0001), and with a composite of all-cause mortality and appropriate ICD shocks (hazard ratio: 3.03; 95% confidence interval: 2.21 to 4.15; p < 0.0001).
  
  
  CONCLUSIONS
  RR-NSVT identified on routine ICD interrogation should be considered an important clinical event. RR-NSVT during ICD interrogation is associated with appropriate ICD shocks and all-cause mortality. The clinical evaluation of patients with RR-NSVT should include intensification of medical therapy, particularly beta-blockers, or other appropriate clinical interventions. (Sudden Cardiac Death in Heart Failure Trial [SCD-HeFT]; NCT00000609).
authors.affiliation: University of Washington, Seattle, Washington 98195, USA.
authors.forename: Jay
authors.initials: J
authors.lastname: Chen
authors.forename: George
authors.initials: G
authors.lastname: Johnson
authors.forename: Anne S
authors.initials: AS
authors.lastname: Hellkamp
authors.forename: Jill
authors.initials: J
authors.lastname: Anderson
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Mark
authors.forename: Kerry L
authors.initials: KL
authors.lastname: Lee
authors.forename: Gust H
authors.initials: GH
authors.lastname: Bardy
authors.forename: Jeanne E
authors.initials: JE
authors.lastname: Poole
mesh_terms: D000368:Aged; D002423:Cause of Death / Q000639:trends; D016001:Confidence Intervals; D016757:Death, Sudden, Cardiac / Q000453:epidemiology* / Q000209:etiology; D017147:Defibrillators, Implantable; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000401:mortality / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012307:Risk Factors; D011795:Surveys and Questionnaires; D015996:Survival Rate / Q000639:trends; D017180:Tachycardia, Ventricular / Q000150:complications / Q000401:mortality / Q000628:therapy*; D014481:United States / Q000453:epidemiology
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