title: The automatic implantable cardioverter-defibrillator in drug-refractory ventricular tachyarrhythmias.
abstract: OBJECTIVE
  To assess the efficacy of the automatic implantable cardioverter-defibrillator in preventing sudden death in high-risk patients.
  
  
  METHODS
  Nonrandomized cohort study.
  
  
  METHODS
  A university teaching hospital with 500 beds.
  
  
  METHODS
  Consecutive sample of 78 patients with symptomatic, sustained ventricular tachyarrhythmias that were previously drug-refractory.
  
  
  METHODS
  Before February 1985, patients received treatment with the defibrillator and amiodarone if they presented with loss of consciousness (group A) and amiodarone alone if they did not lose consciousness (group C). After February 1985, because the availability of the defibrillator was severely curtailed, patients who lost consciousness received treatment with amiodarone alone (group B).
  
  
  RESULTS
  The risk for recurrent arrhythmias was similar between groups. The actuarial risk for sudden death in group B was 31% (95% confidence interval, 11% to 51%) at 1 and 2 years, a value that was significantly higher than that for group A (p less than 0.003) or group C (p less than 0.03). The risk for dying suddenly with the first recurrence was 0.78 in group B, a value that was significantly higher than that for group A (p less than 0.003) or group C (p less than 0.002).
  
  
  CONCLUSIONS
  The defibrillator is highly effective in preventing sudden death in patients whose presenting arrhythmias caused loss of consciousness (group A). In patients whose presenting arrhythmias did not result in loss of consciousness (group C), initial treatment with the defibrillator appears unnecessary.
authors: Division of Cardiology, University of Pittsburgh, Pennsylvania.
authors: R N
authors: RN
authors: Fogoros
authors: S B
authors: SB
authors: Fiedler
authors: J J
authors: JJ
authors: Elson
mesh_terms: D000368:Aged; D000638:Amiodarone / Q000627:therapeutic use; D003131:Combined Modality Therapy; D003645:Death, Sudden / Q000453:epidemiology; D004351:Drug Resistance; D004554:Electric Countershock / Q000009:adverse effects / Q000295:instrumentation*; D004868:Equipment Failure; D005069:Evaluation Studies as Topic; D005260:Female; D006352:Heart Ventricles; D006801:Humans; D008297:Male; D008875:Middle Aged; D019736:Prostheses and Implants / Q000009:adverse effects / Q000600:supply & distribution; D012008:Recurrence; D013610:Tachycardia / Q000188:drug therapy / Q000401:mortality / Q000601:surgery*
chemical_list: D000638:Amiodarone