Ibutilide for rapid conversion of atrial fibrillation or flutter in a mixed critically ill patient population.
BACKGROUND
Ibutilide is an intravenous class III antiarrhythmic agent that has been shown to be effective in converting acute onset atrial fibrillation/flutter in stable medical and cardio-surgical patients. Data on its use in critically ill patients are rare. The aim of this open, non-randomized, prospective trial was to assess the potential role of ibutilide for conversion of recent onset atrial fibrillation/flutter in a mixed critically ill ICU-population.


METHODS
Twenty cardiac-surgical and 17 medical patients with acute tachycardic atrial fibrillation or flutter received up to two 10-min intravenous infusions of 1.0 mg ibutilide.


RESULTS
The cumulative conversion efficacy of ibutilide was 56.8% (21 of 37 patients). The mean time to termination of the arrhythmia was 17.7 +/- 12.5 min (range 4 to 45 min) after the start of the first infusion. Conversion success was significantly higher in medical compared to cardiac-surgical patients (82.4 versus 35.0%, p=.0063). In a multivariate binary stepwise logistic regression analysis adjusted for age, heart rate and reduced left ventricular function, cardiac surgery remained significantly associated with a lower conversion probability (RR, .14; 95%CI, 0.02 to 0.76; p=.0190). Serious, ibutilide-induced ventricular arrhythmias developed in 3/37 patients (8.1%). Two of these 3 patients had a left ventricular ejection fraction < 20%.


CONCLUSIONS
Ibutilide is an effective treatment for conversion of acute tachycardic atrial fibrillation/flutter in critically ill patients. Higher efficacy can be expected in medical than cardiac-surgical patients. Ventricular proarrhythmia, especially in patients with severely depressed left ventricular function represents the most important limitation of ibutilide treatment.
Delle Karth
Georg
G
Department of Cardiology, Medical University of Vienna, Vienna, Austria. georg.delle-karth@meduniwien.ac.at
Schillinger
Martin
M
Geppert
Alexander
A
Haumer
Markus
M
Gwechenberger
Marianne
M
Meyer
Brigitte
B
Heinz
Gottfried
G
Siostrzonek
Peter
P
D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage; D001281:Atrial Fibrillation / Q000188:drug therapy* / Q000453:epidemiology*; D001282:Atrial Flutter / Q000188:drug therapy* / Q000453:epidemiology*; D001317:Austria / Q000453:epidemiology; D003422:Critical Care / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D013449:Sulfonamides / Q000008:administration & dosage*; D016896:Treatment Outcome
D000889:Anti-Arrhythmia Agents; D013449:Sulfonamides; C067192:ibutilide