[Treatment of supraventricular and paroxysmal ventricular tachycardia with bepridil]

Bepridil is a molecule which, apart from its anti-anginal properties, also has antiarrhythmic effects due to its calcium antagonist action which depresses antero and retrograde AV conduction in the physiological pathways. Conduction in accessory AV pathways is also depressed to a lesser and more variable extent. It also has an anti-ventricular arrhythmic action probably due to an associated membrane-stabilising effect. This drug was used intravenously to treat attacks of reciprocating supra-ventricular tachycardia (SVT) (60 p. 100 conversion to sinus rhythm: 6 out of 10 cases of intra-nodal reentry, 6 out of 10 cases of reentry via an accessory pathway) and also in ventricular tachycardia (VT) (7 conversions in 15 patients within 2 to 9 minutes). It was impossible to induce attacks of SVT after administering the drug in about a third of patients; better results were obtained in intra-nodal SVT (5 cases of effective prevention out of 10) than in SVT involving an accessory pathway (1 case out of 10). It was not possible to reinitiate VT after treatment in 3 out of 6 cases (very aggressive pacing methods, a long QT interval and accelerated idio-ventricular rhythm were responsible for the failures). Oral therapy (400 to 800 mg, usually 600 mg daily in 3 doses) prevented any recurrence of SVT in over half the patients (prevention of intranodal SVT: 80 p. 100; prevention of SVT involving an accessory pathway: 13 p. 100) and in 4 out of 6 patients with VT. Provocative pacing studies after intravenous or oral bepridil provide a good indication of long-term efficacy. The drug is generally well tolerated.(ABSTRACT TRUNCATED AT 250 WORDS)