TOPLINE:

In patients undergoing transcatheter aortic valve replacement (TAVR), high‑grade atrioventricular blocks occurring during and after the procedure had distinct mechanisms and predictors. Both atrioventricular and infranodal blocks were observed.

METHODOLOGY:

• Researchers conducted a prospective cohort study to determine the sites of heart blocks that occurred during and after TAVR and predictors of their occurrence.
• They enrolled 409 patients undergoing TAVR (median age, 78.5 years; 44.5% women) at a medical center in Boston, excluding those with preexisting pacemakers.
• An electrophysiologist continuously monitored the ECG and His bundle electrograms during the implantation of the valve.
• The primary endpoint was the development of high-grade atrioventricular blocks (complete heart block or Mobitz type II block). Patients with persistent blocks received permanent pacemakers.
• Researchers determined whether the blocks occurred during the TAVR procedure or were delayed and occurred after the procedure. They followed patients for up to 1 year.

TAKEAWAY:

• A total of 15 patients received permanent pacemakers for persistent high-grade atrioventricular blocks that occurred during TAVR. Blocks were delayed in 25 patients, and most delayed blocks were paroxysmal.
• Blocks occurred in the atrioventricular node during TAVR in five cases (all resolved) and in three delayed cases; the rest were infranodal.
• Preexisting right bundle-branch block predicted the occurrence of blocks during TAVR (P < .001). Delayed block was signaled by a post‑TAVR His-ventricular interval ≥ 80 ms (P = .008) and PR interval > 300 ms (P = .04). There was also a nonsignificant association with atrioventricular Wenckebach cycles ≥ 500 ms (P = .06).
• Patients with blocks occurring during TAVR had a median ventricular pacing of 97.4% at 1 month and 93.5% at 1 year, compared with 5.8% and 9.2%, respectively, in those with delayed blocks.

IN PRACTICE:

“It is clear that electrophysiologists can guide interventional cardiologists to place catheters to record His bundle electrograms with minimal prolongation of the TAVR procedure,” the researchers of this study wrote.

“The data support consideration of a more selective, physiology-guided strategy, which may include shorter observation for transient block, targeted monitoring for newly prolonged conduction intervals, and potential reduction in unnecessary pacemaker implantation,” two experts wrote in an accompanying editor’s note.

SOURCE:

This study was led by Jonathan W. Waks, MD, of Harvard Medical School in Boston. It was published online on December 10, 2025, in JAMA Cardiology.

LIMITATIONS:

This study was conducted at a single center. The number of endpoints was relatively low. Most procedures used balloon-expandable valves; thus, the findings may not apply to self-expanding valves. 

DISCLOSURES:

Several authors reported receiving personal fees, grants, and/or consulting fees from several healthcare, medical devices, and pharmaceutical companies including Medtronic, HeartBeam, and Abbott. One author reported being employed by JenaValve during the conduct of this study. 

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.