Atrioventricular Nodal Reentrant Tachycardia with Multiple Discontinuities in the Atrioventricular Node Conduction Curve: Immediate Success Rates of Radiofrequency Ablation and Long-Term Clinical Follow-up Results as Compared to Patients with Single or No AH-Jumps

Abstract

Some patients with atrioventricular nodal reentrant tachycardia (AVNRT) demonstrate multiple discontinuities (AH jump) in their antegrade AV node conduction curves. We evaluated and compared the immediate success rates, procedure-related complications, long-term clinical follow-up results and recurrence rates after slow pathway ablation in patients with multiple versus single or no AH jumps. The study group consists of 278 consecutive patients (mean age 36.6 +/- 15.7) who underwent ablation for typical AVNRT, divided into three categories according to the number of AH jumps (>/=50 ms) before ablation: Group-1 consisted of 63 patients (23%) with continuous AV node function curves; Group-2 of 183 patients (66%) with a single jump and Group-3 of 32 (12%) patients showing more than one AH jumps. Age was significantly higher in Group-3 as compared to Group-1 (43 +/- 18 years vs. 34 +/- 16 years, p = 0.020). The electrophysiological features of AVNRT did not differ among groups. Before ablation, the maximum AH interval was significantly longer in Group-3 as compared to Groups-1 and -2 ( p < 0.001 for both). AV node antegrade ERP was significantly shorter in Group-3 than in Group-2, both before and after ablation ( p < 0.050 for both). AV node Wenckebach cycle length (WCL) was shorter in Group-3 as compared to both Groups-1 and -2, before and after ablation ( p < 0.050 for all). AV node WCL was prolonged significantly in all groups after ablation ( p < 0.001 for all). Residual dual pathways were present in 37 of 278 patients (13%) after ablation and were significantly more frequent in Group-3 than Group-2 (31% vs. 15%, p = 0.023). Patients with multiple AH jumps are older and more often have residual dual atrioventricular nodal pathway physiology after successful ablation but these features do not affect the immediate and long-term success rates of slow pathway ablation as compared to patients with single or no AH jumps.