Atrioventricular nodal reentrant tachycardia in the elderly: Efficacy and safety of radiofrequency catheter ablation

Background: Radiofrequency (RF) catheter ablation is considered the treatment of choice for patients with atrioventricular nodal reentrant tachycardia (AVNRT). This study examined the efficacy and safety of RF ablation in patients with AVNRT >= 65 years of age. Methods: We retrospectively analyzed data collected in 350 consecutive patients who underwent AVNRT RF ablation between 1995 and 2005. They were divided according to whether they were <65 years (Group 1, n = 280; mean age = 46 +/- 13 years, 69% women) or >= 65 years (Group 2, n = 70; mean age = 72 +/- 6 years, 59% women) of age. Results: Patients in Group 2 more often had structural heart disease (12/70 vs 17/280, P = 0.002) than in Group 1, though there was no difference in the prevalence of syncope (6/70 vs 18/280, P = 0.52) or atrial fibrillation (1/70 vs 6/280, P = 0.70) between the 2 groups. Before RF ablation, patients in Group 2 had a longer mean A-H intervals (90 +/- 31 ms vs 77 +/- 19 ms, P < 0.0001), H-V intervals (44 +/- 6 ms vs 41 +/- 5 ms, P < 0.0001), fast path way refractory period (358 +/- 14 ms, vs 335 +/- 68 ms, P= 0.01), and tachycardia cycle length (394 +/- 71 ms vs. 335 +/- 159 ms, P < 0.0001). A > 140 ms A-H interval was present in 3/70 patients in Group 2 versus 0/280 in Group 1 (P < 0.001). No difference was observed between the 2 groups in primary RF ablation success rate (70/70 vs 277/280, P = 0.38), overall procedure duration (75 +/- 35 minute vs 78 +/- 43 minute, P = 0.61), duration of fluoroscopic exposure (14 +/- 12 minute vs 13 +/- 12 minute, P = 0.63), or number of RF pulses (median 5 vs 4, P = 0.051). Two patients in Group 1 (0.57%) developed 3rd degree AV block requiring permanent pacing. Recurrences of AVNRT were limited to Group 1 (16/280 vs 0/70, P = 0.001). Conclusions: RF ablation of AVNRT was highly effective and safe in patients >= 65 years of age despite a higher prevalence of structural heart disease and longer A-H intervals at baseline. RF ablation might be considered as first-line therapy for the elderly with AVNRT.