Electropharmacological test with pentisomide (CM 7857) in patients with sustained ventricular tachycardia.

Pentisomide (CM 7857) is a new class I antiarrhythmic drug whose effect on sustained ventricular tachycardia has only been slightly investigated to date. The aim of this paper is to examine the pentisomide action on selected patients with ventricular tachycardia inducible during intracavitary electrophysiological study. Thus, 12 patients (9 M, 3 F, mean age: 45.2 years, range: 24-78), all but two with detectable heart disease, underwent electropharmacological tests with pentisomide after they had resulted "non responders" (8 patients) or had had a proarrhythmic worsening effect (3 patients) to electropharmacological tests with amiodarone or flecainide or propafenone or mexiletine. After the inducibility and the reproducibility of ventricular tachycardia has been assessed in the basal state, all patients underwent several attempts to reinduce ventricular tachycardia, during the i.v. infusion of pentisomide 1.5 mg/kg/5 min followed by continuous infusion of 1 mg/kg/h, at the same time drug plasma level was assessed. Ventricular tachycardia inducibility was still inducible after pentisomide, but with a longer cycle length (446 +/- 88 versus 337 +/- 82 msec) than in the basal state (p less than 0.0025). No patients had proarrhythmic worsening effects. The pentisomide plasma level (available in 5 patients) ranged from 3.4 to 22.3 (mean 8.9 micrograms/ml). Four patients underwent chronic oral treatment (in 1 pt in association with amiodarone) with a good clinical outcome (mean follow-up 6.25 months, range 1-12). We stress the absence of proarrhythmic worsening effects and the powerful effect of the drug on ventricular tachycardia cycle length.(ABSTRACT TRUNCATED AT 250 WORDS)