Electrophysiologic Characteristics in Dual AV Nodal Physiology with Inducible and Non-Inducible AVNRT

Background: The purpose of this study is to investigate electrophysiologic characteristics between inducible and non-inducible AVNRT in patients with dual AV nodal physiology. Methods: A total of 1534 subjects (male 605, 44 ± 16 years) with antegrade dual AV nodal physiology who were referred for an electrophysiological study from Jan 1994 to Dec 2010 were investigated. Results: 1262 of all 1532 patients (73.5%) who have antegrade dual AV nodal physiology had inducible AVNRT (group1). Group 2 (n=272) included the patients with inducible tachycardia including WPW syndrome (n=54), AVRT (n=107), atrial arrhythmias (n=29), and without inducible tachycardia (n=82). Group 1 was old ( 45 ±16 years vs. 41 ±16 years, p<0.0001), had more female (63% vs. 50%, p< 0.0001), slow cycle lengths of inducible tachycardia (368 ± 123ms vs. 341 ± 127ms, p=0.004), short AV nodal block cycle length (360 ±67ms vs. 372 ±67ms, p=0.019), short slow pathway ERP (285 ± 44 ms vs. 304 ± 48 ms, p< 0.0001), compared to group 2. By multiple logistic regression, slow pathway ERP (OR 0.99, 95% CI 0.988-0.996, p<0.0001) and old age (OR 1.02, 95% CI 1.002-1.029, p=0.02) were independent predictors of inducible AVNRT. Conclusions: This study suggests that slow pathway ERP has critical role to induce AVNRT.