A clinical study of intravenous cibenzoline in selected patients with recent-onset atrial tachyarrhythmia.

Twenty-five adult patients with sustained atrial tachyarrhythmia (ATA) and without heart failure were treated by intravenous cibenzoline, 1 mg/kg, as a slow bolus infusion, followed by a 8 mg/kg/24 h continuous infusion. Sinus rhythm conversion was observed in 18 patients (72 percent success rate). Severe adverse cardiac events were observed in only one patient (4 percent occurrence rate), as a wide QRS complex tachycardia finally requiring a semiemergency direct-current cardioversion. Two minor side effects were additionally observed. A similar population of 21 patients was conventionally treated with amiodarone, either given intravenously, 15 to 20 mg/kg/24 h, or orally, 30 mg/kg/24 h as a single dose. An identical success rate (15/21; 71 percent) was observed. Our results indicate that in selected patients with ATA, cibenzoline and amiodarone are highly effective for producing sinus rhythm conversion. We suggest that the former drug may be used as a first-line treatment. In case of failure, the latter may constitute an alternative to transthoracic electrical countershock.