title: Early reinitiation of atrial fibrillation following external electrical cardioversion in amiodarone-treated patients.
abstract: Early reinitiation of atrial fibrillation (ERAF) following external or internal electrical cardioversion is one of the factors determining unsuccessful electrical cardioversion. Prevention of ERAF has not been studied systematically in patients on amiodarone therapy.
  
  
  RESULTS
  22 patients had ERAF within 1 min after external electrical cardioversion of atrial fibrillation. 11 patients were on amiodarone therapy and 11 patients had no antiarrhythmic medication. The effect of atropine, post-shock atrial pacing and intravenous ajmaline on ERAF was consecutively tested in these patients. Administration of atropine before repeated defibrillation or post-shock atrial pacing prevented ERAF in 9 of the 11 patients (82%) on amiodarone therapy but in only 3 of 11 patients (27%) without amiodarone (p<0.05). In the remaining patients, intravenous ajmaline was effective in the suppression of ERAF in 5 patients without amiodarone and in 1 patient with amiodarone. The PP interval preceding the atrial premature beat reinitiating atrial fibrillation was nonsignificantly longer in amiodarone-treated patients (1127+/-419 ms) in comparison to patients without amiodarone (896+/-271ms). 27% of patients without amiodarone at the time of electrical cardioversion and 55% of patients with amiodarone remained in sinus rhythm during the follow-up of 29+/-14 and 30+/-14 months, respectively.
  
  
  CONCLUSIONS
  ERAF in patients on amiodarone can be treated by atropine or atrial pacing to prevent bradycardia-dependent ERAF. ERAF in amiodarone-treated patients does not apparently predict late recurrence of atrial fibrillation on continued amiodarone therapy.
authors.affiliation: Medizinische Klinik I, Klinikum Grosshadern, Universität München, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Reithmann
authors.forename: U
authors.initials: U
authors.lastname: Dorwarth
authors.forename: A
authors.initials: A
authors.lastname: Gerth
authors.forename: T
authors.initials: T
authors.lastname: Remp
authors.forename: G
authors.initials: G
authors.lastname: Steinbeck
authors.forename: E
authors.initials: E
authors.lastname: Hoffmann
mesh_terms: D000328:Adult; D000638:Amiodarone / Q000627:therapeutic use*; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000628:therapy*; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects / Q000379:methods; D003131:Combined Modality Therapy; D004554:Electric Countershock / Q000009:adverse effects* / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011336:Probability; D011446:Prospective Studies; D012008:Recurrence; D012016:Reference Values; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D000889:Anti-Arrhythmia Agents; D000638:Amiodarone