A deeper look into conduction system pacing: From the bench to the bedside

Abstract

Conduction system pacing (CSP) has only recently become an alternative to right ventricular apical pacing and cardiac resynchronization therapy and has been reported to provide similar or greater benefits to patients who need right ventricular pacing. 1 Sharma P.S. Dandamudi G. Herweg B. et al. Permanent His-bundle pacing as an alternative to biventricular pacing for cardiac resynchronization therapy: a multicenter experience. Heart Rhythm. 2018; 15: 413-420 Abstract Full Text Full Text PDF PubMed Scopus (188) Google Scholar , 2 Abdelrahman M. Subzosh F.A. Beer D. et al. Clinical outcomes of His bundle pacing compared to right ventricular pacing. J Am Coll Cardiol. 2018; : 712319-712330 Google Scholar , 3 Upadhyay G.A. Vijayaraman P. Nayak H.M. et al. His corrective pacing or biventricular pacing for cardiac resynchronization in heart failure. J Am Coll Cardiol. 2019; 74: 157-159 Crossref PubMed Scopus (65) Google Scholar The “Achilles’ heel” of CSP is our lack of an understanding of what we are pacing and how we actually pace the conduction system that is variably insulated beginning in the His bundle region. It is unknown whether pacing is capturing the conduction system or the surrounding tissues through a virtual electrode effect. High His bundle pacing thresholds have been demonstrated to be a concern by several groups with a wide ranging incidence, but in our experience, it occurs in up to 25% of patients and loss of CSP was seen in 17% of patients. 4 Teigeler T. Kolominsky J. Vo C. et al. Intermediate-term performance and safety of His-bundle pacing leads: a single-center experience. Heart Rhythm. 2021; 18: 743-749 Abstract Full Text Full Text PDF PubMed Scopus (17) Google Scholar ,5 Vijayaraman P. Naperkowski A. Subzposh F.A. et al. Permanent His-bundle pacing: long-term lead performance and clinical outcomes. Heart Rhythm. 2018; 15: 696-702 Abstract Full Text Full Text PDF PubMed Scopus (115) Google Scholar It is in this context that Nanthakumar and colleagues from the University of Toronto studied this problem by carefully evaluating the biophysics of CSP. In this issue of Heart Rhythm Journal, Niri et al 6 Niri A. Bhaskaran A. Asta J. et al. Stimulation and propagation of activation in conduction tissue: implications for left bundle branch area pacing. Heart Rhythm. 2021; 18: 813-821 Abstract Full Text Full Text PDF PubMed Scopus (5) Google Scholar provide us with important new insights into how we can best pace the conduction system. Stimulation and propagation of activation in conduction tissue: Implications for left bundle branch area pacingHeart RhythmVol. 18Issue 5PreviewCharacterizing wavefront generation and impulse conduction in left bundle (LB) has implications for left bundle branch area pacing (LBBAP). Full-Text PDF