Intravenous cibenzoline in the management of acute supraventricular tachyarrhythmias

Summary Intravenous cibenzoline was evaluated in 37 patients with acute supraventricular tachyarrhytymias and a ventricular rate >120 beats/min. The presenting arrhythmia was atrial fibrillation in 15 patients, atrial flutter in 5, ectopic atrial tachycardia in 11, and paroxysmal atrioventricular (AV) junctional reentrant tachycardia in 6 patients. Intravenous cibenzoline was administered as a bolus given over 2 minutes, at a dose of 1 mg/kg in the first 26 patients and 1.2 mg/kg in the subsequent 11 patients, 15 minutes following failure of placebo (isotonic glucose). The results were evaluated 15 minutes after the intravenous injection. Restoration of sinus rhythm was obtained in 3 out of 6 patients with paroxysmal AV junctional tachycardia (50%) and in 7 out of 31 patients (23%) with atrial tachyarrhythmias (5 out of 15 patients with atrial fibrillation and 2 out of 16 patients with ectopic atrial tachycardia or atrial flutter). Five additional patients with atrial tachyarrhythmias had slowing of ventricular rate below 100 beats/min. Therefore, a satisfactory result, that is, restoration of sinus rhythm or slowing of ventricular rate, occurred in 15 patients (40.5%). Side effects were transient, including visual disturbance (one patient), asymptomatic widening of QRS complex (three patients), incessant reciprocating tachycardia (one patient), and acceleration of ventricular rate (eight patients), resulting in 1:1 flutter, with poor tolerance in two patients. In conclusion, intravenous cibenzoline may be useful in selected patients with supraventricular tachyarrhythmias. Careful monitoring is recommended during therapy in view of the possible occurrence of 1:1 atrial flutter.