title: Efficacy of internal cardioversion for chronic atrial fibrillation in patients with and without left ventricular dysfunction.
abstract: Internal cardioversion can restore sinus rhythm with energies below 6-10 J, often without anaesthesia/sedation. We investigated its safety and short-/medium-term efficacy in patients with persistent atrial fibrillation (AF) with left ventricular dysfunction (defined as ejection fraction < or = 40%). Among 34 patients with persistent AF who agreed to receive internal cardioversion, 16 had left ventricular dysfunction and 18 did not (the groups were similar as regards age, duration of AF and pretreatment with amiodarone). Internal CV was performed delivering 3.0/3.0-ms biphasic shocks between coil catheters using a step-up protocol. Sinus rhythm was always restored. General anaesthesia (administered only when discomfort was not tolerated) was required only in 2 of the 16 (12.5%) patients with left ventricular dysfunction. The defibrillation threshold was similar in patients with and without left ventricular dysfunction (10.2+/-6.9 vs. 8.4+/-4.9 J; p=0.37). Short-term (within 72 h) AF recurrence rates in the presence and absence of left ventricular dysfunction were 19% (3/16) and 6% (1/18), respectively (p=0.51). After cardioversion, all patients received antiarrhythmic drugs (mostly amiodarone in patients with left ventricular dysfunction and class IC agents in the remainder). With mean follow-up periods of about 220 days, AF recurrence rates among patients with and without left ventricular dysfunction were 50% (8/16) and 28% (5/18), respectively (p=0.328). We conclude that even in patients with left ventricular dysfunction, internal CV is safe and effective, minimizing risks from anaesthesia. Although these patients may have a higher risk of short- or medium-term AF recurrence, 6-month maintenance of sinus rhythm is possible in about 50% of cases.
authors.affiliation: Institute of Cardiology, University of Bologna, Policlinico, S. Orsola Azienda Ospedaliera S. Orsola-Malpighi, Via Massarenti 9, 40138 Bologna, Italy. cardio1@almadns.unibo.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Boriani
authors.forename: Mauro
authors.initials: M
authors.lastname: Biffi
authors.forename: Claudia
authors.initials: C
authors.lastname: Camanini
authors.forename: Ivan
authors.initials: I
authors.lastname: Corazza
authors.forename: Cristian
authors.initials: C
authors.lastname: Martignani
authors.forename: Cinzia
authors.initials: C
authors.lastname: Valzania
authors.forename: Margherita
authors.initials: M
authors.lastname: Gallina
authors.forename: Francesco
authors.initials: F
authors.lastname: Grigioni
authors.forename: Romano
authors.initials: R
authors.lastname: Zannoli
authors.forename: Claudio
authors.initials: C
authors.lastname: Rapezzi
authors.forename: Angelo
authors.initials: A
authors.lastname: Branzi
mesh_terms: D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D002908:Chronic Disease; D017147:Defibrillators, Implantable; D004452:Echocardiography; D004554:Electric Countershock; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000000981:diagnostic imaging / Q000503:physiopathology; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D007558:Italy; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D013223:Statistics as Topic; D013318:Stroke Volume / Q000502:physiology; D013997:Time Factors; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*
chemical_list: D000889:Anti-Arrhythmia Agents