title: Efficacy of amiodarone treatment on cardiac symptom, function, and sympathetic nerve activity in patients with dilated cardiomyopathy: comparison with beta-blocker therapy.
abstract: BACKGROUND
  Amiodarone, which is an antiarrhythmic drug used to treat life-threatening arrhythmias, is effective in patients with chronic heart failure. However, its effectiveness compared with beta-blockers has not yet been reported.
  
  
  RESULTS
  In 30 patients (mean age, 57 +/- 13 years) with dilated cardiomyopathy, we compared 15 patients receiving amiodarone (group A) with 15 patients receiving metoprolol (group B). Before and after 1 year of treatment, cardiac iodine 123 metaiodobenzylguanidine uptake was assessed from the total defect score, heart-to-mediastinum activity ratio based on delayed images, and washout rate. New York Heart Association class and echocardiographic left ventricular ejection fraction were also assessed. In both groups the total defect score decreased (from 25 +/- 11 to 16 +/- 10 in group A, P <.01; from 26 +/- 10 to 18 +/- 11 in group B, P <.01), the heart-to-mediastinum activity ratio increased (from 1.63 +/- 0.16 to 1.81 +/- 0.29 in group A, P <.01; from 1.63 +/- 0.21 to 1.85 +/- 0.3 in group B, P <.01), and the washout rate decreased (from 51% +/- 12% to 38% +/- 14% in group A, P <.01; from 48% +/- 11% to 37% +/- 8% in group B, P <.01). Left ventricular ejection fraction increased (from 30% +/- 9% to 42% +/- 11% in group A, P <.01; from 26% +/- 7% to 46% +/- 16% in group B, P <.01) and New York Heart Association functional class improved (from 3.1 +/- 0.5 to 1.8 +/- 0.7 in group A, P <.01; from 2.9 +/- 0.5 to 1.7 +/- 0.6 in group B, P <.01).
  
  
  CONCLUSIONS
  Amiodarone treatment can improve cardiac symptom, function, and sympathetic nerve activity, as evaluated by I-123 metaiodobenzylguanidine imaging in patients with dilated cardiomyopathy, which improves to a similar extent with beta-blocker treatment.
authors.affiliation: Guma Prefectural Cardiovascular Center, Maebashi, Japan. toyama.t@cvc.pref.gunma.jp
authors.forename: Takuji
authors.initials: T
authors.lastname: Toyama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hoshizaki
authors.forename: Ryotaro
authors.initials: R
authors.lastname: Seki
authors.forename: Naoki
authors.initials: N
authors.lastname: Isobe
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Adachi
authors.forename: Shigeto
authors.initials: S
authors.lastname: Naito
authors.forename: Shigeru
authors.initials: S
authors.lastname: Oshima
authors.forename: Koichi
authors.initials: K
authors.lastname: Taniguchi
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D000638:Amiodarone / Q000627:therapeutic use*; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D002311:Cardiomyopathy, Dilated / Q000150:complications / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000627:therapeutic use*; D008875:Middle Aged; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D020127:Recovery of Function; D013564:Sympathetic Nervous System / Q000000981:diagnostic imaging / Q000187:drug effects; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000209:etiology
chemical_list: D000319:Adrenergic beta-Antagonists; D000889:Anti-Arrhythmia Agents; D019275:Radiopharmaceuticals; D008790:Metoprolol; D000638:Amiodarone