Ahran Arnold Zachary I Whinnett Pugazhendhi Vijayaraman Login or register to view PDF. Order reprints 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report of permanent His bundle pacing (HBP) in 2000, the stylet-driven technique of its earliest incarnation has been superseded by a more successful stylet-less approach.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. Keywords His bundle pacing, left bundle branch pacing, left bundle area pacing, deep septal pacing, conduction system pacing, cardiac resynchronisation therapy, bundle branch block. Disclosure ADA has received honoraria from Medtronic. PV has received honoraria from Medtronic, Biotronik, Boston Scientific and Abbott; Research and Fellowship support from Medtronic; and patent pending for His bundle pacing delivery tool. ZIW has received honoraria from Medtronic, Boston Scientific, Micropace and Abbott. Correspondence Pugazhendhi Vijayaraman, Geisinger Heart Institute, Geisinger Wyoming Valley Medical Center, MC 36-10, 1000 E Mountain Blvd, Wilkes-Barre, PA 18711, US. E: [email protected] Support ADA is supported by the National Institute of Health Research Imperial Biomedical Research Centre and the British Heart Foundation Imperial Centre of Research Excellence (RE/18/4/34215). ZIW receives research funding from the British Heart Foundation, National Institute of Health Research Imperial Biomedical Research Centre and the Coronary Flow Trust. Received date 27 April 2020 Accepted date 30 June 2020 Citation Arrhythmia & Electrophysiology Review 2020; epub ahead of press. DOI http://sci-hub.tw/10.15420/aer.2020.14 Open access This work is open access under the CC-BY-NC 4.0 License which allows users to copy, redistribute and make derivative works for non-commercial purposes, provided the original work is cited correctly. Right ventricular apical pacing (RVAP) results in dyssynchronous ventricular activation that can lead to impairment of ventricular function. Alternative myocardial pacing sites such as RV septal pacing (RVSP) and RV outflow tract pacing still rely on myocardial cell-to-cell conduction and have not been shown to prevent pacing-induced cardiomyopathy.1 Biventricular pacing (BVP) certainly improves upon RVAP, but still produces a non-physiological activation pattern.2 Direct pacing of the His–Purkinje conduction system offers the ability to preserve physiological activation of the ventricles in patients with intrinsically normal, narrow QRS complexes. In patients with bundle branch block (BBB), conduction system pacing can deliver cardiac resynchronisation therapy (CRT) by correcting BBB to synchronise ventricular activation.3 The originally favoured site of conduction system stimulation is the His bundle, and there is now large global experience of pacing at this site with considerable published follow-up data. More recently, new techniques have pulled focus to pacing of the region of the left bundle branch, which has a growing evidence base.4 In this state-of-the-art review of His–Purkinje conduction system pacing, we assess recent evidence and current practice and explore emerging and future directions in this rapidly evolving field.
