Intra-procedural ECG Changes During TAVR

Transcatheter aortic valve replacement (TAVR) has become a well-established alternative to surgical intervention for patients with severe symptomatic aortic stenosis (AS) (1-4). The rates of most TAVR complications have declined over time due to the improvement of operator experience and technological advancement; however, conduction abnormalities continue to persist (5). New-onset left bundle branch block (LBBB) and atrioventricular nodal block (AVB) are among the most common conduction disturbances (6). Additionally, there is an increased incidence of delayed (after discharge) HAVB (2nd-degree AVB Mobitz type 2 or 3rd-degree AVB) in patients with preexisting (pre-TAVR) right bundle branch block (RBBB) and new-onset LBBB post-TAVR, 13.2%, and 8.5%, respectively (7). Currently, conduction disturbances post-TAVR are assessed via post-procedural ECG, and physicians performing TAVR are not provided feedback in real time. The use of intraprocedural ECG could provide insight into the status of the heart's conduction system during TAVR and prevent irreversible injury, requiring post-procedural monitoring at intensive cardiac care unit (usually with a temporary pacemaker in situ) or even permanent pacemaker implantation. Furthermore, given the increased incidence of HAVB after valve replacement in patients with preexisting RBBB and new-onset LBBB, continued post-procedural ECG monitoring in this particular subset of patients may provide more information on the progression of conduction disturbances after TAVR. This will be a small-scale, early feasibility study evaluating intra-procedural ECG changes, such as AVB (1st, 2nd, or 3rd degree), or new-onset LBBB, in patients undergoing TAVR, to inform a future, larger scale, prospective investigation.