title: Why QRS Duration Should Be Replaced by Better Measures of Electrical Activation to Improve Patient Selection for Cardiac Resynchronization Therapy.
abstract: Cardiac resynchronization therapy (CRT) is a well-known treatment modality for patients with a reduced left ventricular ejection fraction accompanied by a ventricular conduction delay. However, a large proportion of patients does not benefit from this therapy. Better patient selection may importantly reduce the number of non-responders. Here, we review the strengths and weaknesses of the electrocardiogram (ECG) markers currently being used in guidelines for patient selection, e.g., QRS duration and morphology. We shed light on the current knowledge on the underlying electrical substrate and the mechanism of action of CRT. Finally, we discuss potentially better ECG-based biomarkers for CRT candidate selection, of which the vectorcardiogram may have high potential.
authors.affiliation: Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands.
authors.forename: Elien B
authors.initials: EB
authors.lastname: Engels
authors.affiliation: Department of Cardiology, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Masih
authors.initials: M
authors.lastname: Mafi-Rad
authors.affiliation: Department of Cardiology, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Antonius M W
authors.initials: AM
authors.lastname: van Stipdonk
authors.affiliation: Department of Cardiology, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Kevin
authors.initials: K
authors.lastname: Vernooy
authors.affiliation: Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands. frits.prinzen@maastrichtuniversity.nl.
authors.forename: Frits W
authors.initials: FW
authors.lastname: Prinzen
mesh_terms: D000200:Action Potentials; D058406:Cardiac Resynchronization Therapy; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D006329:Heart Conduction System / Q000503:physiopathology*; D006333:Heart Failure / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy*; D006339:Heart Rate; D006801:Humans; D018579:Patient Selection; D011237:Predictive Value of Tests; D013318:Stroke Volume; D013997:Time Factors; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy*; D016277:Ventricular Function, Left
keywords: Cardiac mapping; Cardiac resynchronization therapy; Electrocardiography; Left bundle-branch block; Vectorcardiography