Efficacy and safety of ibutilide for cardioversion of atrial flutter and fibrillation in patients receiving amiodarone or propafenone.
OBJECTIVE
The effectiveness and safety of ibutilide (IB) use in patients receiving amiodarone or propafenone for atrial flutter (AFL) and atrial fibrillation (AF) were compared to IB alone.


RESULTS
In 104 consecutive patients with AF (65%) or AFL (35%), receiving amiodarone (n = 46), propafenone (n = 30), or no specific antiarrhythmic drug (n = 28), IB was given for cardioversion. Fifteen patients in amiodarone group were loaded with 1.2 g intravenously before IB administration. The mean duration of arrhythmia episode was 23 +/- 65 days, while 85% of patients had structural heart disease. The left ventricle ejection fraction was 57 +/- 10% and the left atrium size was 4.2 +/- 0.6 cm. The conversion efficacy did not differ among groups (62% for amiodarone vs 55% for propafenone vs 64% for IB alone). The QTc intervals were significantly prolonged, at 10 minutes and 30 minutes after IB administration, in amiodarone group (from 449 +/- 88 to 496 +/- 92 ms, 508 +/- 52 ms; P = 0.001) and in the group where IB was used alone (from 434 +/- 45 to 517 +/- 74 ms, 492 +/- 65 ms; P < 0.001), while it remained unchanged in propafenone group (from 464 +/- 52 to 471 +/- 80 ms, 489 +/- 93 ms; P = 0.536). The only predictor of conversion was the presence of AFL (P = 0.009). Five patients developed ventricular tachycardias after IB administration (two in propafenone, one in amiodarone, and two in IB group).


CONCLUSIONS
The use of IB in patients receiving amiodarone or propafenone for AFL or AF is equally effective and safe as the use of IB alone. The presence of AFL is the stronger predictor factor for cardioversion.
Fragakis
Nikolaos
N
2nd Cardiac Department, GH G. Papanikolaou, Kromnis 42, 55131 Thessaloniki, Greece. nfrag@panafonet.gr
Papadopoulos
Nikolaos
N
Papanastasiou
Soultana
S
Kozirakis
Miltiadis
M
Maligkos
George
G
Tsaritsaniotis
Evangelos
E
Katsaris
George
G
D000328:Adult; D000368:Aged; D000638:Amiodarone / Q000627:therapeutic use*; D000704:Analysis of Variance; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000188:drug therapy*; D001282:Atrial Flutter / Q000188:drug therapy*; D016009:Chi-Square Distribution; D004359:Drug Therapy, Combination; D004554:Electric Countershock / Q000379:methods; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D011405:Propafenone / Q000627:therapeutic use*; D011446:Prospective Studies; D013449:Sulfonamides / Q000627:therapeutic use*; D016896:Treatment Outcome
D000889:Anti-Arrhythmia Agents; D013449:Sulfonamides; C067192:ibutilide; D011405:Propafenone; D000638:Amiodarone