ELECTROPHYSIOLOGIC CHARACTERISTICS AND RADIOFREQUENCY CATHETER ABLATION IN PATIENTS WITH MULTIPLE ATRIOVENTRICULAR NODAL REENTRY TACHYCARDIAS

Information about the mechanism and radiofrequency catheter ablation o f multiple atrioventricular (AV) nodal reentry tachycardias is limited , Among the 550 consecutive patients with AV nodal reentry tachycardia , 36 with multiple forms of AV nodal reentry tachycardia were included in this study. Electrophysiologic characteristics, as well as the eff icacy and safety radiofrequency ablation, were evaluated, Results show ed that anterograde dual pathways were seen in 32 patients and triple pathways in 2, and retrograde dual pathways were seen in 23 patients a nd triple pathways in 11. Twenty-two patients had 2 types, 7 had 3 typ es, 5 had 4 types, and 2 had 5 types of AV nodal reentry tachycardia a nd echoes. After delivering radiofrequency energy to the target sites, 32 patients had no induction of AV nodal reentry tachycardia and only 4 had induction of 1 echo, Furthermore, 22 patients (61%) had simulta neous elimination or modification of the slow and/or intermediate path ways in the anterograde and retrograde direction, During the follow-up period of 19 +/- 14 months, 2 patients had recurrence of tachycardia. Thus, multiple anterograde and retrograde AV nodal pathways were pres ent in the human AV node and they constituted the substrates of reentr y circuits, Radiofrequency catheter ablation was safe and effective in eliminating the slow and intermediate pathways for maintenance of mul tiple AV nodal reentry tachycardias.