The prevalence and characteristics of coexisted atrioventricular nodal reentrant tachycardia and idiopathic left fascicular ventricular tachycardia.

Background: Coexistence of idiopathic left fascicular ventricular tachycardia (ILFVT) and atrioventricular nodal reentrant tachycardia (AVNRT) has been rarely reported.

Objectives: The study aimed at elucidating the prevalence of coexisted AVNRT in patients with ILFVT during longitudinal follow-up. The electrophysiological properties and clinical predictors of coexisted ILFVT and AVNRT were investigated.

Methods: From 1999 to 2017, a total of 108 patients (age: 33.7 ± 14.3, 84 male) with ILFVT from one tertiary center were consecutively enrolled. The prevalence of coexisted arrhythmias was explored during a longitudinal follow-up and the electrophysiological parameters from the index procedure were compared.

Results: During a mean follow-up period of 106.8 ± 69.5 months, 21 of 108 patients (19.4%) had coexisted AVNRT. The electrophysiological study demonstrated patients with coexisted ILFVT and AVNRT were characterized by more antegrade dual AV node conduction (52.4% vs. 19.5%, P = 0.002; 9.5%), shorter antegrade slow pathway effective refractory period (285.1 ± 34.1 ms vs. 329.2 ± 69.2 ms, P = 0.034), longer retrograde fast pathway effective refractory period (368.9 ± 56.7 ms vs. 312.5 ± 95.2, P = 0.036), and less VA dissociation (19.0% vs. 60.9%, P = 0.001) than those without a coexisted AVNRT. Multivariate logistic analysis showed that presence of antegrade dual AV nodal physiology and retrograde VA conduction could predict a coexisted AVNRT in patients with ILFVT (P = 0.005, OR: 4.80, 95% CI: 1.65-14.37 and P = 0.002, OR: 0.14, 95% CI: 0.04-0.49, respectively).

Conclusion: There was a high prevalence of coexisted AVNRT in patients with ILFVT during longitudinal follow-up. The presence of antegrade dual AV nodal physiology and retrograde VA conduction can predict the coexisted AVNRT in patients with ILFVT.