INTRAVENOUS CIBENZOLINE IN THE MANAGEMENT OF ACUTE SUPRAVENTRICULAR TACHYARRHYTHMIAS

Intravenous cibenzoline was evaluated in 37 patients with acute suprav entricular tachyarrhythmias 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 atriove ntricular (AV) junctional reentrant tachycardia in 6 patients. Intrave nous 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 subseq uent 11 patients, 15 minutes following failure of placebo (isotonic gl ucose). The results were evaluated 15 minutes after the intravenous in jection. Restoration of sinus rhythm was obtained in 3 out of 6 patien ts 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 tach ycardia or atrial flutter). Five additional patients with atrial tachy arrhythmias had slowing of ventricular rate below 100 beats/min. There fore, a satisfactory result, that is, restoration of sinus rhythm or s lowing of ventricular rate, occurred in 15 patients (40.5%). Side effe cts were transient, including visual disturbance (one patient), asympt omatic widening of QRS complex (three patients), incessant reciprocati ng tachycardia (one patient), and acceleration of ventricular rate (ei ght patients), resulting in 1:1 flutter, with poor tolerance in two pa tients. In conclusion, intravenous cibenzoline may be useful in select ed patients with supraventricular tachyarrhythmias. Careful monitoring is recommended during therapy in view of the possible occurrence of 1 :1 atrial flutter.