[Clinical experience with propafenone in paroxysmal supraventricular reciprocating tachycardias]

We studied the long term antiarrhythmic efficacy of Propafenon, (300-900 mg/day) in 25 patients (18 females, 7 males; mean age 37,6; follow-up 10 +/- 9,3 months) affected by episodes of disabling paroxysmal supraventricular reciprocating tachycardia. We performed an electrophysiologic study using cardiac catheterization in all 25 patients. Fifteen patients had a Wolff-Parkinson-White syndrome; in 8/25 pts the reentrant circuit was in the atrio-ventricular node and in 2/25 pts it was into the atrium. Ten of fifteen patients with Wolff-Parkinson-White syndrome and 5/8 patients with the reentrant circuit in the atrio-ventricular node have been treated with Propafenon according to the results of the acute test performed during electrophysiologic study. Good results (no recurrences of paroxysmal supraventricular reciprocating tachycardia or less frequent recurrences at a much slower heart rate) have been obtained in 13/15 patients with Wolff-Parkinson-White syndrome and in 5/8 patients with the reentrant circuit in the atrio-ventricular node. The acute drug test with Propafenon during electrophysiologic study was predictive of the clinical response in 100% of patients with Wolff-Parkinson-White syndrome and in 60% of patients with the reentrant circuit in the atrio-ventricular node. We conclude that: 1) Propafenon may be good alternative to Amiodarone in the chronic treatment of pts affected by paroxysmal supraventricular reciprocating tachycardia, especially in patients with Wolff-Parkinson-White syndrome; 2) electrophysiologic study to evaluate Propafenon efficacy is most valuable in patients with Wolff-Parkinson-White syndrome.