title: Low-energy internal cardioversion in patients with long-lasting atrial fibrillation refractory to external electrical cardioversion: results and long-term follow-up.
abstract: OBJECTIVE
  Low-energy internal cardioversion is a new electrical treatment for patients with persistent atrial fibrillation. This paper evaluates the efficacy and safety of low-energy internal cardioversion in patients with long-lasting atrial fibrillation refractory to external electrical cardioversion, and the clinical outcome of such patients.
  
  
  RESULTS
  The study population consisted of 55 patients [32 male, mean age 65 +/- 10 years, 48 (87%) with underlying heart disease] with long-lasting (mean 18 +/- 34 months) atrial fibrillation in whom external cardioversion had failed to restore sinus rhythm. Two custom-made catheters were used: one positioned in the right atrium and one in the coronary sinus or the left pulmonary artery. A standard catheter was inserted into the right ventricular apex to provide R wave synchronization. Sinus rhythm was restored in 52 patients (95%) with a mean defibrillating energy of 6.9 +/- 2.6 J (320 +/- 60 V). No complications were observed. During follow-up (mean 18 +/- 9 months), 16 patients (31%) suffered early recurrence (< or = 1 week) of atrial fibrillation and 20 patients (38%) had late recurrence (> 1 week, mean 3.5 +/- 3.6 months) of atrial fibrillation. Six patients with a late recurrence again underwent cardioversion and five of these maintained sinus rhythm. Therefore, a total of 21/52 patients (40%) were in sinus rhythm at the end of follow-up. No clinical difference was found between patients with and without recurrences.
  
  
  CONCLUSIONS
  Low-energy internal cardioversion is a useful means of restoring sinus rhythm in patients with long-lasting atrial fibrillation refractory to external electrical cardioversion. More than one-third of patients maintained sinus rhythm during long-term follow-up.
authors.affiliation: Division of Cardiology, Umberto I Hospital, Mestre, Venice, Italy. cardio.mestre@tin.it
authors.forename: G
authors.initials: G
authors.lastname: Gasparini
authors.forename: A
authors.initials: A
authors.lastname: Bonso
authors.forename: S
authors.initials: S
authors.lastname: Themistoclakis
authors.forename: F
authors.initials: F
authors.lastname: Giada
authors.forename: A
authors.initials: A
authors.lastname: Raviele
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000209:etiology / Q000628:therapy*; D006328:Cardiac Catheterization / Q000295:instrumentation*; D002908:Chronic Disease; D004554:Electric Countershock / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D019233:Retreatment; D012189:Retrospective Studies; D017211:Treatment Failure; D016896:Treatment Outcome