His bundle pacing has now entered guidelines from the European Society of Cardiology (ESC).

The update to the cardiac pacing and cardiac resynchronization therapy (CRT) guidelines also brought changes on pacing after syncope or transcatheter aortic valve implantation (TAVI), as well as revisions to recommendations on loop recorders, CRT in heart failure, and implantable device MRI safety.

The guideline, last revised in 2013, was released at the ESC virtual meeting and simultaneously online in the European Heart Journal by writing group chair Michael Glikson, MD, of the Hebrew University in Jerusalem, and colleagues.

Physiologic pacing is a whole new section in the guidelines, with growing evidence on His corrective pacing, largely from observational studies.

His bundle pacing (HBP) got a class IIa recommendation for consideration as an option for CRT candidates in whom coronary sinus lead implantation is unsuccessful.

A IIb recommendation was issued for use in combination with a ventricular backup lead in patients indicated for a “pace-and-ablate” strategy for rapidly conducted supraventricular arrhythmia, especially in the case of narrow QRS, and as an alternative to right ventricular pacing in patients with atrioventricular (AV) block and a left ventricular ejection fraction under 40% when more than 20% ventricular pacing is anticipated.

When patients are treated with HBP, there was a class I recommendation that device programming be tailored to its specific requirements, and a class IIa recommendation that a right ventricular lead be used as a “backup” in situations like pacemaker dependency or for sensing in case of issues with detection.

U.S. guidelines are likely to head in a similar direction soon, given how many studies are being published to flesh out the evidence base, suggested Kalyanam Shivkumar, MD, PhD, of the University of California Los Angeles and editor-in-chief of JACC: Clinical Electrophysiology.

The guideline noted that left bundle branch pacing is also promising, but with even more scarce data and concern about long-term lead performance and feasibility of lead extraction.

“Recommendations for using left bundle branch area pacing cannot therefore be formulated at this stage,” Glikson’s group wrote. “However, conduction system pacing (which includes HBP and left bundle branch area pacing) is very likely to play a growing role in the future, and the current recommendations will probably need to be revised once more solid evidence of safety and efficacy (from randomized trials) is published.”

From the clinical practice perspective, Shivkumar speculated that physicians are likely to use the recommendations on His pacing somewhat interchangeably for left bundle branch pacing, which has become more preferred.

For TAVI, the guidelines gave class I recommendations to permanent pacing in patients with complete or high-degree AV block persisting for 24 to 48 hours after the procedure and those with new onset alternating bundle branch block.

A class IIa recommendation was given to ambulatory ECG monitoring or electrophysiologic study of patients with new post-TAVI left bundle branch block with a QRS over 150 ms or PR interval over 240 ms with no further prolongation during more than 48 hours post-procedure.

While the level of evidence was not high (“C”), “these are very useful pointers for practice,” Shivkumar said.