To assess the role of transesophageal pacing (TP) at very high rates i
n the follow-up of patients with recurrent and sustained paroxysmal at
rial fibrillation (AF) on therapy, the authors studied 15 patients (10
women, 5 men; aged forty-four to seventy-seven years old). Of them on
ly 1 had a mild mitral regurgitation; none had hyperthyroidism or acut
e ischemic heart disease. They tested propafenone (P) at a dose of 1.4
-2 mg/kg over ten minutes as an intravenous bolus and 0.5 mg/minute as
intravenous maintenance for two hours and then 300 mg twice daily ora
lly and chronically. Serial TPs at very rapid rates (up to 600 bpm) we
re performed to test the long-term efficacy of P to prevent paroxysmal
AF. The mean follow-up was fifteen months (nine to twenty-four months
). Results: Intravenous P converted AF in five to ninety minutes (mean
twenty-one minutes) in 9/15 patients (conversion rate of 60%); in an
additional 4 patients oral P converted AF in two to fifteen hours. In
the other 2 patients P failed to convert AF. Three patients experience
d recurrence of AF in the early follow-up. Of the 10 patients who comp
leted the entire protocol, only 1, who had mild mitral prolapse regurg
itation and AF induction by TP, experienced new episodes of AF during
follow-up. No significant side effects were noted during P therapy. Co
nclusions: Propafenone appears safe and effective for controlling and
preventing recurrent and sustained AF. Transesophageal pacing is a val
id tool for predicting the efficacy of long-term therapy in the follow
-up of patients with paroxysmal atrial fibrillation.