Cardioversion of atrial fibrillation with ibutilide: when is it most effective?
BACKGROUND
Atrial fibrillation (AF) is found in 1% of persons above the age of 60 years. More than 5% of the population older than 69 years and about 14% of octogenarians are at risk for this arrhythmia. It is estimated that 1.5 to 3 million persons in the United States alone suffer from AF. The public health implications and attendant morbidity are a significant drain on our health care system.


OBJECTIVE
The purpose of this study was to determine the clinical and echocardiographic predictors of success in converting AF of > or = 24 h duration.


METHODS
Demographic and clinical and echocardiographic parameters of 101 patients with recent onset AF (> 24 h) who received ibutilide were studied.


RESULTS
Of 101 patients, 56 (55%) converted to sinus rhythm. Age, gender, hypertension, diabetes mellitus, left ventricular ejection fraction (< or = 35%), congestive heart failure, and previous medication for rate control had no significant effect on the conversion rate. Conversion rate was only 30% (9/30 patients) in the presence of an enlarged left atrium (LA > or = 5 cm) and 37.7% (23/61 patients) in the presence of mitral valve disease (MVD), whereas the conversion rate was 82.5% (33/40 patients) in the absence of MVD and 85% (29/34 patients) in the absence of both enlarged LA and MVD (p = <0.001). Patients with coronary artery disease (CAD) also exhibited a significantly greater response to ibutilide than patients without CAD (77 vs. 46%, p-value 0.005).


CONCLUSIONS
As a therapy for cardioversion of AF, ibutilide is most effective in a selected subgroup patients, such as in patients with CAD and in patients without MVD and/or markedly enlarged left atrium.
Das
Mithilesh Kumar
MK
Division of Cardiology (Starr4), New York Presbyterian Hospital-Cornell University Medical College, New York 10021, USA. mithileshdas@hotmail.com
Cheriparambil
Kuruvilla
K
Bedi
Ashwini
A
Kassotis
John
J
Reddy
Chatla V R
CV
Saul
Barry
B
Makan
Majesh
M
D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000188:drug therapy*; D016009:Chi-Square Distribution; D004452:Echocardiography; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D012307:Risk Factors; D013449:Sulfonamides / Q000627:therapeutic use*; D013997:Time Factors; D016896:Treatment Outcome
D000889:Anti-Arrhythmia Agents; D013449:Sulfonamides; C067192:ibutilide