[How and why treat supraventricular tachycardias].

The present study deals with pathophysiological and clinical aspects of two major supraventricular tachyarrhythmias: atrial fibrillation and reciprocating tachycardia. The main hemodynamic effects and the most frequent complications are examined, and therapeutic indications are given concerning pharmacologic, surgical or electrical treatment. Twelve patients with supraventricular tachycardia (5 with intranodal reentry and 7 with A-V by-pass tract) were treated with Propafenone and evaluated by repeated electrophysiological testing. Acute infusion of Propafenone (2 mg/kg over 10 minutes) interrupted the induced tachycardia in 9 of 11 patients (81%); Propafenone prevented the induction of the arrhythmia in 60% of patients with nodal reentry and in none with A-V by-pass. Electrophysiological evaluation repeated after one week of oral treatment (300 mg three times daily) in 5 patients indicated complete protection in two patients; in three the arrhythmia was still inducible but had a significantly lower rate. Finally, with regard to electrical treatment, data are presented concerning 10 patients with supraventricular reentrant tachycardia (4 intranodal, 6 with A-V by-pass tract) in whom an antiarrhythmic pacemaker was implanted (5 type Pasar Telectronics, 5 type Medtronic SP 500). The results were highly favourable in 9 patients with complete control of the arrhythmia.