乌鸦传媒

NEW ORLEANS -- The Heart Rhythm Society issued the first U.S. guidelines to address use of conductive system pacing with the intent to prevent or mitigate heart failure.

Conduction system pacing, which includes His bundle pacing or left bundle branch (LBB) area pacing, got a IIa recommendation when effective cardiac resynchronization therapy (CRT) cannot be achieved, according to a new guideline in , published in conjunction with the annual meeting of the Heart Rhythm Society

Conduction system pacing got a class IIb recommendation for patients needing permanent pacing who have left ventricular ejection fraction (LVEF) of 36-50% but are not expected to require substantial ventricular pacing (20-40%), with or without LBB block (LBBB).

It also got a IIb recommendation for heart failure patients with LVEF 36-50%, LBBB, and QRS duration ≥150 ms and for heart failure patients with LVEF ≤35% and non-LBBB pattern for QRS duration both <150 and ≥150 ms.

LBB area pacing got a IIb recommendation for patients with normal EF who are anticipated to require less than substantial ventricular pacing.

Patients undergoing pacemaker implantation who are expected to require substantial ventricular pacing (20-40%) may be considered for cardiac physiologic pacing to reduce the risk of pacing-induced cardiomyopathy.

"This is the first guideline on conduction system pacing and also updates guidelines on cardiac resynchronization therapy," Mina Chung, MD, of the Cleveland Clinic and chair of the guideline committee, told 乌鸦传媒.

Among the take-home messages in the guideline, the 60-member writing group noted "substantially" better evidence for CRT in heart failure than what is available to support conduction system pacing.

"Multiple randomized controlled trials have shown a beneficial effect of cardiac resynchronization therapy in reducing heart failure symptoms and hospitalization, improving left ventricular function, and increasing survival," they wrote.

"The majority of data on conduction system pacing are observational, and long-term data on lead survival are lacking," the writers stated. "Robust data from ongoing, larger randomized trials are expected."

Physiologic pacing first entered European guidelines in 2021, garnering a IIb recommendation for consideration pf His bundle pacing as an option for CRT candidates in whom coronary sinus lead implantation is unsuccessful. It also got a IIb recommendation 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 block and low LVEF when more than 20% ventricular pacing is anticipated.

Electrophysiologists had been anticipating that U.S. guidelines might head in a similar direction for the increasingly popular approach to pacing. Cardiac physiologic pacing aims to restore or preserve synchrony of ventricular contraction by engaging the intrinsic conduction system.

Among the many recommendations in the U.S. guideline, the writing group highlighted the following:

• Periodic assessment of ventricular function to detect pacing-induced or dyssynchrony-induced cardiomyopathy was recommended when patients need substantial right ventricular pacing or have chronic LBBB
• Shared decision-making was recommended on cardiac physiologic pacing device implantation, with consideration of the patient's values, preferences, goals of care, and prognosis, along with the potential benefits and short- and long-term risks (device-associated infection, battery longevity, future lead management issues, evidence base, and considerations at the end of life)
• Remote monitoring and in-person echocardiographic and electrocardiographic evaluations are essential during post-implant follow-up to ensure appropriate capture and optimization of therapy
• In patients with an unfavorable response to cardiac resynchronization therapy with biventricular pacing, optimization of both medical and device therapies is recommended
• In selected patients with congenital heart disease or congenital atrioventricular block, cardiac resynchronization therapy or conduction system area pacing may be considered

The guideline was a joint effort of the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society.

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