Electrophysiological observations during and after transcatheter aortic valve replacement

Conduction disturbances requiring permanent pacing frequently complicate transcatheter aortic valve replacement (TAVR). The understanding of mechanisms causing conduction block is incomplete.

This study aimed to characterize the acute and delayed electrophysiological (EP) effects of TAVR on the atrioventricular (AV) conduction system.

We conducted a single-center prospective cohort study of 409 patients undergoing TAVR. All patients underwent 12-lead electrocardiography and EP study (EPS) immediately before and after valve implantation, with continuous electrocardiography and EP monitoring during the TAVR. 7 patients with AV block underwent repeat EPS 1-12 days after TAVR.

TAVR was associated with significant prolongation of sinus cycle length, atrio-His and His-ventricular (HV) intervals, and Wenckebach cycle length (all P < .0001). Transient AV-nodal conduction block occurred in 8% of patients with intraprocedural AV block and 12% with postprocedural block. Infranodal block occurred in 57 patients, but resolved in 41 by the end of the procedure. Marked HV interval prolongation (>100 ms) 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-nodal and infranodal conduction abnormalities was seen in all.

Peri-TAVR conduction disturbances may involve both the AV node 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 that many conduction abnormalities resolved within 2-4 weeks, supporting a refined post-TAVR risk stratification strategy.

NCT04982406.