title: Clinical electrophysiology, efficacy and safety of chronic oral cibenzoline therapy in refractory ventricular tachycardia.
abstract: The electrocardiographic (ECG) and electrophysiologic (EP) effects, clinical efficacy and safety of oral cibenzoline therapy were evaluated using a twice-daily dosing regimen in patients with refractory ventricular tachycardia (VT). Twenty patients underwent EP studies in the control (drug-free) state and after cibenzoline therapy using an incremental dose-titration protocol. Oral cibenzoline (2.4 to 5.8 mg/kg/day) was administered in doses of 130, 160 or 190 mg at 12-hour intervals. ECG and EP variables, 24-hour ambulatory ECG monitoring and programmed electrical stimulation studies were obtained in the control state and after 11 +/- 4 days of cibenzoline therapy. Cibenzoline therapy prolonged the mean PR interval (from 179 +/- 29 to 201 +/- 36 ms, p less than 0.001), the mean QRS duration (from 107 +/- 21 to 130 +/- 25 ms, p less than 0.001), and the mean QTc interval (from 422 +/- 25 to 460 +/- 42 ms, p less than 0.001). It increased the mean HV interval (from 50 +/- 17 to 65 +/- 20 ms, p less than 0.01) and mean right ventricular effective refractory period (from 245 +/- 24 to 266 +/- 27 ms, p less than 0.01). After cibenzoline therapy, 5 patients (25%) had suppression of inducible sustained VT during programmed electrical stimulation. High-degree atrioventricular block occurred in 2 patients. Chronic cibenzoline therapy (mean follow-up 24 +/- 3 months) remained effective in long-term suppression of VT in 4 patients. Two patients had to discontinue therapy because of gastrointestinal intolerance. Cibenzoline is effective in suppression of refractory VT in selected patients using a twice-daily dosing schedule.
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000097:blood / Q000494:pharmacology / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D004558:Electric Stimulation; D004562:Electrocardiography; D004594:Electrophysiology; D005260:Female; D006321:Heart / Q000187:drug effects; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D007093:Imidazoles / Q000008:administration & dosage / Q000009:adverse effects / Q000097:blood / Q000494:pharmacology / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D011877:Radionuclide Imaging; D012008:Recurrence; D013610:Tachycardia / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000503:physiopathology
chemical_list: D000889:Anti-Arrhythmia Agents; D007093:Imidazoles; C032151:cifenline