title: Effects of antiarrhythmic drugs on inappropriate shocks in patients with implantable cardioverter defibrillators.
abstract: BACKGROUND
  Patients with atrial fibrillation (AF) or congestive heart failure (CHF) are more vulnerable to inappropriate shocks from implantable cardioverter-defibrillators (ICDs), but the effect of antiarrhythmic drugs in these patients remains unknown.
  
  
  RESULTS
  A total of 55 patients with AF and/or CHF (New York Heart Association functional class > or =III) who had ICDs were divided into 3 groups [amiodarone (n=24), sotalol (n=12), beta-blocker (n=19)] and the cumulative rates of inappropriate shocks were compared. The baseline characteristics of the 3 groups were not significantly different. The 4-year event rate of inappropriate shocks was 27.3% in the amiodarone group, 54.3% in the sotalol group, and 70.6% in the beta-blocker group (amiodarone vs beta-blocker: log-rank p=0.003; sotalol vs beta-blocker: log-rank p=0.16; amiodarone vs sotalol: log-rank p=0.29). Amiodarone reduced the risk of inappropriate shocks significantly as compared with beta-blockers (hazard ratio (HR) 0.17; 95% confidence interval (CI) 0.05-0.64; p=0.008), whereas sotalol did not (HR 0.57; 95%CI 0.19-1.68; p=0.3). Amiodarone was discontinued in 4 patients (16.7%) because of pulmonary toxicity and the dose was reduced in 4 patients (16.7%) because of a thyroid function abnormality.
  
  
  CONCLUSIONS
  Amiodarone is more effective than sotalol or beta-blockers in preventing inappropriate ICD shocks in patients with AF or CHF, but it has a significant risk of drug-related adverse effects.
authors.affiliation: Department of Internal Medicine, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors.forename: Chang Hoon
authors.initials: CH
authors.lastname: Lee
authors.forename: Gi-Byoung
authors.initials: GB
authors.lastname: Nam
authors.forename: Hyun-Gu
authors.initials: HG
authors.lastname: Park
authors.forename: Hyung Yong
authors.initials: HY
authors.lastname: Kim
authors.forename: Kyoung-Min
authors.initials: KM
authors.lastname: Park
authors.forename: Jun
authors.initials: J
authors.lastname: Kim
authors.forename: Kee-Joon
authors.initials: KJ
authors.lastname: Choi
authors.forename: You-Ho
authors.initials: YH
authors.lastname: Kim
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage / Q000494:pharmacology / Q000633:toxicity; D000368:Aged; D000638:Amiodarone / Q000008:administration & dosage / Q000494:pharmacology / Q000633:toxicity; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage* / Q000494:pharmacology / Q000633:toxicity; D001281:Atrial Fibrillation / Q000628:therapy; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D004556:Electric Injuries / Q000188:drug therapy / Q000209:etiology / Q000517:prevention & control*; D005260:Female; D006333:Heart Failure / Q000628:therapy; D006801:Humans; D008171:Lung Diseases / Q000139:chemically induced; D008297:Male; D008875:Middle Aged; D012769:Shock / Q000517:prevention & control; D013015:Sotalol / Q000008:administration & dosage / Q000494:pharmacology / Q000633:toxicity
chemical_list: D000319:Adrenergic beta-Antagonists; D000889:Anti-Arrhythmia Agents; D013015:Sotalol; D000638:Amiodarone