We present our experience on the efficacy of
propafenone in ten symptomatic patients with
Wolff-Parkinson-White syndrome. The symptoms were
dizziness in seven patients and
syncope in three patients. While experiencing the symptoms, three of them presented an episode of
atrial fibrillation, the shortest preexcited RR intervals being 140, 190, and 200 ms. In the other seven patients, the ECG was not recorded during the symptoms, but an episode of
atrial fibrillation was subsequently induced by transesophageal pacing. The shortest preexcited RR intervals during induced
atrial fibrillation were 180, 200, 270, 240, 230, 250, and 200 ms. Seven patients had both
atrial fibrillation and
supraventricular tachycardia.
Propafenone (1-2 mg/kg) administered IV in only the patients with sustained
atrial fibrillation (spontaneous in two and induced in one patient) prolonged the shortest preexcited RR intervals from 190, 200, and 180 ms to 340, 335, and 340 ms. In the other seven patients,
propafenone was not given IV because
atrial fibrillation rapidly deteriorated into
ventricular fibrillation (one patient) or spontaneously reverted within 1-2 minutes to sinus rhythm (six patients). After oral
propafenone, serial trans-esophageal pacing studies reinduced
atrial fibrillation in 4 of 6 patients (the shortest preexcited RR intervals increased from 190, 180, 200, and 270 ms to 420, 320, 340, and 380 ms); only in one patient was it possible after
propafenone to induce an
atrial flutter without preexcitation. After
propafenone therapy in 4 of 7 patients,
supraventricular tachycardia was not inducible.(ABSTRACT TRUNCATED AT 250 WORDS)