Fera MS, Carunchio A, Burattini M, Mazza A, Coletta C, Galati A, Ceci V. Ospedale S. Spirito, Roma. G Ital Cardiol 1997 Feb;27(2):152-63. BACKGROUND: There is no written data about the efficacy of transesophageal electropharmacologic test (TEPT) to guide antiarrhythmic therapy in the prophylaxis of paroxysmal atrial fibrillation (PAF) recurrences. Aim of this study was to assess the efficacy of TEPT compared to empiric treatment in the prophylaxis of PAF. METHODS: One-hundred-sixty patients (pts) with previous episodes of PAF were randomized in two groups: Gr A (90 pts) was submitted to basal transesophageal electrophysiologic study (BTES); Gr B (70 pts) was submitted to randomized empiric antiarrhythmic therapy with flecainide (F), propafenone (P) and sotalol (S). The end-points of stimulation protocol in Gr A were the induction of sustained atrial fibrillation (SAF)- > or = 1 min duration- or the end of protocol. SAF was inducible in 68/90 pts (Gr A1) while it was not in 22/90 pts (Gr A2). Pts in Gr A1 were subsequently submitted to TEPT at steady-state of F, P or S randomized in first choice. Pts responders (R) (SAF non inducible) were submitted to TEPT with other antiarrhythmic drugs randomized in second choice: R were followed-up with the same drug in chronic oral assumption, while non responders (NR) were submitted to TEPT with the last drug and followed-up with the same drug both in R and NR case. The same stimulation protocol was employed in TEPT as in BTES. Pts in Gr A2 withdrew from the study. During follow-up all-pts were submitted to periodic specialist examinations every three months. In case of PAF recurrence pts withdrew from the study. RESULTS: Mean follow-up duration in the study population was 17.5 +/- 8.5 months. One-hundred-eight TEPT were performed in Gr A1: 36 tests with F, 40 with P and 32 with S. Twenty pts were R with F (55% of tests) and 17 finished the follow-up, 22 pts were R with P (55% of tests) and 16 finished the follow-up, 19 pts were R with S (59% of tests) and 15 finished the follow-up; 3 pts with F, 2 pts with P and 2 pts with S were NR in last choice and finished the follow-up. In Gr A1 61/68 pts (90%) were R and 55/68 (81%) finished the follow-up (13 pts withdrew from the study). In Gr B (70 pts) 23 pts were randomized to F and 20 finished the follow-up, 24 pts were randomized to P and 20 finished the follow-up, 23 pts were randomized to S and 20 finished the follow-up (10 pts withdrew from the study). PAF recurrences during follow-up in Gr A1 were in 15/55 pts (27%): 9/48 pts (19%) R and 6/7 pts (86%) NR, and in Gr B in 41/60 pts (68%). Gr A1 vs Gr B p < 0.001. Univariate and multivariate statistical analysis showed the empiric treatment as the only variable with high predictive value for PAF recurrences (risk ratio 1.53). PPV and NPV of TEPT were respectively 86 and 81%. CONCLUSIONS: TEPT-guided antiarrhythmic therapy in the prophylaxis of PAF recurrences seems to be an effective method in predicting the efficacy of the chronic antiarrhythmic therapy, when compared to the empiric treatment. The non inducibility of SAF at TEPT would have a high predictive value for event-free follow-up.