His–Purkinje Conduction System Pacing: State of the Art in 2020

Abstract

Conduction system pacing involves directly stimulating the specialised His–Purkinje cardiac conduction system with the aim of activating the ventricles physiologically, in contrast to the dyssynchronous activation produced by conventional myocardial pacing. Since the first report of permanent His bundle pacing (HBP) in 2000, the stylet-driven technique of its earliest incarnation has been superseded by a more successful stylet-less approach. Widespread uptake has led to a much greater evidence base. Single-centre observational studies have now been supported by large multicentre, international registries, mechanistic studies and the first randomised controlled trials. New evidence has elucidated mechanisms of HBP and illustrated the nature and magnitude of its potential benefits for preventing pacing-induced cardiomyopathy and correcting bundle branch block. Left bundle branch pacing (LBBP) is a newer technique in which the lead is fixed deep into the left side of the intraventricular septum to allow capture of the left bundle, distal to the His bundle. LBBP holds promise as a method for physiological pacing that overcomes some of the fixation, threshold and sensing challenges of HBP. In this state-of-the-art review of His–Purkinje conduction system pacing, the authors assess recent evidence and current practice and explore emerging and future directions in this rapidly evolving field.

Left ventricular activation time and pattern are preserved with both selective and nonselective His bundle pacing

“…S-HBP and NS-HBP were defined according to internationally recognized criteria (set out in the Online Appendix). 1 , 2 , 3 Patients with various indications for HBP were recruited: resynchronization of bundle branch block (BBB), optimization of atrioventricular interval in heart failure, or prevention of pacing-induced cardiomyopathy in atrioventricular block. All patients gave written, informed consent and the study was approved by the local ethics committee (13/LO/1440).…”

Leadless Left Ventricular Endocardial Pacing and Left Bundle Branch Area Pacing for Cardiac Resynchronisation Therapy

“…LBBAP and HBP restore physiological activation through the native conduction system, and LBBAP may be more feasible than HBP due to a wider target area. [ 5 , 36 ] Although HBP has been shown to lead to narrowing of the QRS duration and cardiac resynchronisation in clinical and simulation studies, implantation can be difficult and the success rates vary from 56% to 95%. [ 37 – 40 ] Follow-up can be problematic due to oversensing of atrial signals, undersensing of ventricular signals, lead displacement, and rising capture thresholds with premature battery depletion.…”

“…[ 43 ] Currently, LBBAP is usually delivered using a SelectSecure 3830 pacing lead (Medtronic), and confirmation is dependent on several criteria, which are currently being updated and validated. [ 5 , 36 , 44 ] The predominant complications of LBBAP relate to the risk of septal perforations and lead dislodgements. LBBAP may be affected by intrinsic conduction and programming optimal atrioventricular delays will be important.…”

“…[ 3 , 4 ] Conduction system pacing with His bundle pacing (HBP) or left bundle branch area pacing (LBBAP) provides physiological activation using the native conduction system. [ 5 ] LV endocardial pacing enables access to faster endocardial conduction and site-specific pacing, unlike conventional CRT. [ 6 – 9 ] This article will discuss LV endocardial pacing and LBBAP in detail, including the potential benefits and risks of each intervention and future directions.…”

Troubleshooting Programming of Conduction System Pacing

“…Conduction system pacing (CSP) is gaining widespread adoption as an alternative to right ventricular (RV) pacing and – in some instances – as an alternative to biventricular pacing for CRT. [ 1 ] Whereas tools are evolving to facilitate implantation, there are currently no generators specifically designed to facilitate programming of CSP. Proper device programming is essential to ensure patient safety and obtain the greatest benefit from pacing therapy.…”