[Anti-arrhythmia and pro-arrhythmia effects of oral cibenzoline therapy in sustained ventricular tachycardia].

The efficacy and safety of the new class-I antiarrhythmic drug cibenzoline was assessed in 12 patients with spontaneous and inducible ventricular tachycardia. Programmed ventricular stimulation, 24-h ambulatory electrocardiogram (ECG), and continuous ECG monitoring were performed without antiarrhythmic drugs and after oral administration of 254 +/- 80 mg of the substance. Oral cibenzoline suppressed the induction of tachycardia in only one patient. Induction of tachycardia was more difficult in two patients, unchanged in four patients, and easier in two patients. Cycle length of induced tachycardia and QT-interval corrected for frequency were not changed significantly; effective refractory period of the right ventricle was prolonged. Twenty-four hours of ambulatory monitoring during cibenzoline treatment (n = 9) showed no significant increase in the frequency of ventricular premature complexes. However, spontaneous sustained ventricular tachycardia developed in three patients after initiation of cibenzoline treatment. In two patients, termination of induced ventricular tachycardia was significantly more difficult under cibenzoline; several DC-shocks were required to terminate the tachycardia. Thus, the use of oral cibenzoline in patients with sustained spontaneous and inducible ventricular tachycardias showed a low antiarrhythmic efficacy at programmed stimulation and a high incidence of spontaneous ventricular tachycardia.