Turco P, Guarino P, Parente A, Viola V, Candelmo F, Bellizzi G, Foffa A, Morella A, Martino DF. Electrophysiology Laboratory, Ospedale Civile Ariano-AV, Irpino-AV, Italy. Angiology 1994 Feb;45(2):95-100. To assess the role of transesophageal pacing (TP) at very high rates in the follow-up of patients with recurrent and sustained paroxysmal atrial fibrillation (AF) on therapy, the authors studied 15 patients (10 women, 5 men; aged forty-four to seventy-seven years old). Of them only 1 had a mild mitral regurgitation; none had hyperthyroidism or acute 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 orally and chronically. Serial TPs at very rapid rates (up to 600 bpm) were 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 experienced recurrence of AF in the early follow-up. Of the 10 patients who completed the entire protocol, only 1, who had mild mitral prolapse regurgitation and AF induction by TP, experienced new episodes of AF during follow-up. No significant side effects were noted during P therapy. CONCLUSIONS: Propafenone appears safe and effective for controlling and preventing recurrent and sustained AF. Transesophageal pacing is a valid tool for predicting the efficacy of long-term therapy in the follow-up of patients with paroxysmal atrial fibrillation.