title: Physiological mechanisms of QRS narrowing in bundle branch block patients undergoing permanent His bundle pacing.
abstract: His bundle pacing is increasingly used to avoid chronic right ventricular pacing, and electrically resynchronize ventricular activation by narrowing or normalizing the QRS interval in left and right bundle branch block. The mechanisms by which this occurs remain poorly understood. In this review, the proposed mechanisms and evidence supporting them are discussed. Also discussed are aspects of mechanisms that are not completely supported by the evidence. We also review the differences and physiological bases for direct vs. indirect His bundle capture, and the physiological mechanisms for QRS narrowing vs. normalization following His bundle pacing.
authors.affiliation: UCLA Cardiac Arrhythmia Center, Los Angeles, CA.
authors.forename: Alexandra E
authors.initials: AE
authors.lastname: Teng
authors.affiliation: UCLA Cardiac Arrhythmia Center, Los Angeles, CA.
authors.forename: Louis
authors.initials: L
authors.lastname: Massoud
authors.affiliation: UCLA Cardiac Arrhythmia Center, Los Angeles, CA. Electronic address: oajijola@mednet.ucla.edu.
authors.forename: Olujimi A
authors.initials: OA
authors.lastname: Ajijola
mesh_terms: D000818:Animals; D002036:Bundle of His / Q000503:physiopathology*; D002037:Bundle-Branch Block / Q000503:physiopathology* / Q000517:prevention & control*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D004562:Electrocardiography / Q000379:methods; D019317:Evidence-Based Medicine; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008955:Models, Cardiovascular; D016896:Treatment Outcome
keywords: His bundle; His bundle pacing; cardiac resynchronization; left bundle branch block