Cardiac Physiologic Pacing for the Avoidance and Mitigation of Heart Failure
Introduction
Introduction
Top 10 Take-Home Messages
- Cardiac physiologic pacing (CPP) is defined here as any form of cardiac pacing intended to restore or preserve synchrony of ventricular contraction. CPP can be achieved by engaging the intrinsic conduction system via conduction system pacing (CSP; which includes His bundle pacing [HBP] or left bundle branch area pacing [LBBAP]), or cardiac resynchronization therapy (CRT), the latter most commonly achieved by biventricular (BiV) pacing using a coronary sinus (CS) branch or epicardial left ventricular (LV) pacing lead.
- The strength of evidence for CRT in heart failure (HF) is substantially greater than what is available to support CSP. Multiple randomized controlled trials (RCTs) have shown a beneficial effect of CRT in reducing HF symptoms and hospitalization, improving LV function, and increasing survival. The majority of data on CSP are observational, and long-term data on lead survival are lacking. Ongoing and planned studies are likely to provide future guidance on the use of CSP compared to CRT.
- Response to CRT has a variable definition and includes improvements in mortality and HF hospitalization but may also include improvement in clinical parameters of HF, stabilization of ventricular function, or prevention of progression of HF.
- Periodic assessment of ventricular function is recommended for patients who require substantial right ventricular (RV) pacing (≥20%–40%) or have chronic left bundle branch block (LBBB) to detect pacing- or dyssynchrony-induced cardiomyopathy.
- Patients undergoing pacemaker implant who are expected to require substantial ventricular pacing (≥20%–40%) may be considered for CPP to reduce the risk of pacing-induced cardiomyopathy (PICM).
- Patients with left ventricular ejection fraction (LVEF) of 35%–50% who are expected to require less than substantial (<20%–40%) ventricular pacing may not have a sizable benefit from CPP; therefore, traditional RV lead placement with minimization of ventricular pacing, CSP, or CRT in the setting of LBBB are all acceptable options.
- New recommendations for left bundle branch area pacing are made for patients with normal LVEF (class of recommendation [COR] 2b) needing a pacing device.
- CRT remains recommended for patients with HF, LVEF ≤35%, LBBB, QRS duration ≥150 ms, and New York Heart Association (NYHA) class II–IV symptoms on guideline-directed medical therapy (COR 1). New recommendations are made for CSP when effective CRT cannot be achieved (COR 2a); and for CRT in patients with select characteristics (eg, female sex), as they may derive benefit from CRT at QRS durations of 120–149 ms (COR 1). New recommendations are also made for patients with HF, LVEF 36%–50%, LBBB, and QRS duration ≥150 ms for CRT or CSP to maintain or improve LVEF (COR 2b).
- New CPP recommendations are provided for patients with HF, LVEF ≤35%, and non-LBBB pattern for QRS duration both <150 and ≥150 ms (COR 2b).
- During implantation and follow-up of patients with CPP devices, electrocardiographic demonstration of BiV (for CRT) or conduction system (for CSP) capture is essential.
Other Important Considerations
- Shared decision-making is recommended when contemplating implantation of a CPP device and should include considerations of the patient's values, preferences, goals of care, and prognosis, along with the potential benefits, short- and long-term risks (in particular, device-associated infection), effects of these pacing modalities on battery longevity, future lead management issues, evidence base for different types of CPP, and considerations at end of life.
- Substantial RV pacing of ≥20%–40% may induce cardiomyopathy in a subset of patients.
- Remote monitoring and in-person echocardiographic and electrocardiographic evaluations are essential during follow-up after implantation of a CPP device to ensure appropriate capture and optimization of therapy.
- In patients with HF with improved LVEF or benefit from CRT (including improvement, stabilization, or partial reversal of natural decline), continuation of CRT with BiV pacing is recommended at device replacement.
- In patients with an unfavorable response to CRT with BiV pacing, optimization of both medical and device therapies is recommended.
- In selected patients with congenital heart disease (CHD) or congenital atrioventricular block (AVB), CRT or conduction system area pacing may be considered.
- Long-term data on CSP are emerging, with current data derived from observational studies or small randomized clinical trials without long-term follow-up. Robust data from ongoing, larger randomized trials are expected.
Definitions
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Indications for CPP in Atrial Fibrillation (AF)
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Pre-procedure Evaluation and Preparation
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Implant Procedure
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