Propafenone was administered during electrophysiologic testing to determine its efficacy and safety for terminating and preventing reinduction of paroxysmal supraventricular reentrant
tachycardia. Four men and 10 women (mean age 50 years, range 28 to 69) were studied. Five patients had
Wolff-Parkinson-White syndrome with orthodromic atrioventricular (AV) reentrant
tachycardia, three had a
concealed accessory pathway with AV reentrant
tachycardia and six had
tachycardia due to reentry within the AV node. In the five patients with
Wolff-Parkinson-White syndrome,
propafenone terminated reentrant
tachycardia in three (the
tachycardia was reinducible in one) and had no effect in two. In the three patients with a
concealed accessory pathway,
propafenone terminated reentrant
tachycardia in all three and prevented reinduction of the
tachycardia in two. In the six patients with
tachycardia due to reentry within the AV node,
propafenone terminated and prevented reinduction of reentrant
tachycardia.
Propafenone had no effect on blood pressure, heart rate, PA interval, AV node refractoriness or rate of reentrant
tachycardia.
Propafenone significantly (p less than 0.05) prolonged the AH, HV, QRS and ventriculoatrial intervals and decreased the AV node Wenckebach rate. Of the nine patients receiving long-term oral
propafenone therapy, eight had a reduction of at least 90% in reentrant
tachycardia during a mean follow-up period of 14.5 months (range 11 to 22); all eight patients had had noninducible reentrant
tachycardia after intravenous
propafenone. One patient had increased frequency of reentrant
tachycardia; this patient had had inducible reentrant
tachycardia after intravenous
propafenone. In conclusion, intravenously administered
propafenone terminated reentrant
tachycardia in 85% of patients and prevented reinduction in 71%, with no adverse hemodynamic effects.