Electrophysiologic Observations During and After Transcatheter Aortic Valve Replacement (TAVR)

BACKGROUND: Conduction disturbances requiring permanent pacing frequently complicate transcatheter aortic valve replacement (TAVR). Understanding of mechanisms causing conduction block is incomplete. OBJECTIVE: To characterize the acute and delayed electrophysiologic effects of TAVR on the atrioventricular (AV) conduction system. METHODS: We conducted a single-center prospective cohort study of 409 patients undergoing TAVR. All patients underwent 12-lead electrocardiography and electrophysiologic study (EPS) immediately before and after valve implantation, with continuous ECG and EP monitoring during the TAVR. Seven patients with AV block underwent repeat EPS 1-12 days after TAVR. RESULTS: TAVR was associated with significant prolongation of sinus cycle length, AH and HV intervals, as well as Wenckebach cycle length (all P100ms) without conduction block occurred in 6.4% of patients during TAVR. Intra-His Wenckebach-type block occurred in 9 patients. In 7 patients with follow-up EPS 1-12 days after TAVR improvement or resolution of AV node and infra-nodal conduction abnormalities was seen in all. CONCLUSIONS: Peri-TAVR conduction disturbances may involve both the AV nodal and His bundle. The usual parameters indicating need for permanent pacing (marked HV prolongation) do not apply to TAVR patients. Distinguishing nodal from infranodal involvement can inform prognosis, anticipated recovery, and pacemaker decision-making, particularly given many conduction abnormalities resolved within 2-4 weeks, supporting a refined post-TAVR risk stratification strategy.