title: Biventricular Paced QRS Area Predicts Acute Hemodynamic CRT Response Better Than QRS Duration or QRS Amplitudes.
abstract: Vectorcardiographic (VCG) QRS area of left bundle branch block (LBBB) predicts acute hemodynamic response in cardiac resynchronization therapy (CRT) patients. We hypothesized that changes in QRS area occurring with biventricular pacing (BV) might predict acute hemodynamic CRT response (AHR).
  
  
  
  VCGs of 624 BV paced electrocardiograms (25 LBBB patients with 35 different pacing configurations) were calculated according to Frank's orthogonal lead system. Maximum QRS vector amplitudes (XAmpl, YAmpl, ZAmpl, and 3DAmp) and QRS areas (XArea, YArea, ZArea, and 3DArea) in the orthogonal leads (X, Y, and Z) and in 3-dimensional projection were measured. Volume of the 3D vector loop and global QRS duration (QRSD) on the surface electrocardiogram were assessed. Differences (Δ) in VCG parameters between BV paced and LBBB QRS complexes were calculated. An increase of 10% in dP/dt max was considered as AHR. LBBB conduction is characterized by a large ZArea(109 μVs, interquartile range [IQR]:75;135), significantly larger than XArea(22 μVs, IQR:10;57) and YArea(44 μVs, IQR:32;62, P < 0.001). Overall, QRS duration, amplitudes, and areas decrease significantly with BV pacing (P < 0.001). Of all VCG parameters, 3DAmpl, Δ3DAmpl, ZArea,ΔZArea, Δ3DArea, and ΔQRSD differentiate AHR response from nonresponse (P < 0.05). ΔZAreapredicted best positive AHR (area under the curve = 0.813) and outperformed any other VCG parameter or QRSD measurement.
  
  
  
  Of all VCG parameters, reduction in QRS area, calculated in Frank's Z lead, predicts acute hemodynamic response best. This method might be an easy, noninvasive tool to guide CRT implantation and optimization.
authors.affiliation: Ghent University Hospital, Heart Center, Ghent, Belgium.
authors.forename: Jan
authors.initials: J
authors.lastname: DE Pooter
authors.affiliation: Ghent University Hospital, Heart Center, Ghent, Belgium.
authors.forename: Milad
authors.initials: M
authors.lastname: El Haddad
authors.affiliation: Ghent University Hospital, Heart Center, Ghent, Belgium.
authors.forename: Marc
authors.initials: M
authors.lastname: DE Buyzere
authors.affiliation: Medtronic Plc, Bakken Research Center, Maastricht, The Netherlands.
authors.forename: Hernandez Alfonso
authors.initials: HA
authors.lastname: Aranda
authors.affiliation: Medtronic Plc, Bakken Research Center, Maastricht, The Netherlands.
authors.forename: Richard
authors.initials: R
authors.lastname: Cornelussen
authors.affiliation: Medtronic Plc, Bakken Research Center, Maastricht, The Netherlands.
authors.forename: Berthold
authors.initials: B
authors.lastname: Stegemann
authors.affiliation: Guy's and St Thomas' NHS Trust, London, UK.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Rinaldi
authors.affiliation: The Second Department of Coronary Artery Disease, Institute of Cardiology, Warsaw, Poland.
authors.forename: Maciej
authors.initials: M
authors.lastname: Sterlinski
authors.affiliation: Department of Cardiology, Congenital Heart Diseases and Electrotherapy Silesian Center of Heart Disease, Zabrze, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Sokal
authors.affiliation: Faculty of Medicine, Imperial College Healthcare NHS Trust, London, England, UK.
authors.forename: Darrel P
authors.initials: DP
authors.lastname: Francis
authors.affiliation: Ghent University Hospital, Heart Center, Ghent, Belgium.
authors.forename: Luc
authors.initials: L
authors.lastname: Jordaens
authors.affiliation: Ghent University Hospital, Heart Center, Ghent, Belgium.
authors.forename: Roland X
authors.initials: RX
authors.lastname: Stroobandt
authors.affiliation: Ghent University Hospital, Heart Center, Ghent, Belgium.
authors.forename: Frederic
authors.initials: F
authors.lastname: VAN Heuverswyn
authors.affiliation: Ghent University Hospital, Heart Center, Ghent, Belgium.
authors.forename: Frank
authors.initials: F
authors.lastname: Timmermans
mesh_terms: D000200:Action Potentials; D000368:Aged; D019540:Area Under Curve; D002037:Bundle-Branch Block / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D058406:Cardiac Resynchronization Therapy; D004562:Electrocardiography; D005060:Europe; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D008877:Middle East; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D013318:Stroke Volume; D013997:Time Factors; D016896:Treatment Outcome; D014672:Vectorcardiography; D016277:Ventricular Function, Left
keywords: QRS area; biventricular pacing; cardiac resynchronization therapy; vectorcardiography