title: Body surface mapping using an ECG belt to characterize electrical heterogeneity for different left ventricular pacing sites during cardiac resynchronization: Relationship with acute hemodynamic improvement.
abstract: Electrical heterogeneity (EH) during cardiac resynchronization therapy may vary with different left ventricular (LV) pacing sites.
  
  
  
  The purpose of this study was to evaluate the relationship between such changes and acute hemodynamic response (AHR).
  
  
  
  Two EH metrics-standard deviation of activation times and mean left thorax activation times-were computed from isochronal maps based on 53-electrode body surface mapping during baseline AAI pacing and biventricular (BiV) pacing from different pacing sites in coronary veins in 40 cardiac resynchronization therapy-indicated patients. AHR at different sites was evaluated by invasive measurement of LV-dp/dtmaxat baseline and BiV pacing, along with right ventricular (RV)-LV sensing delays and QRS duration.
  
  
  
  The site with the greatest combined reduction in standard deviation of activation times and left thorax activation times from baseline to BiV pacing was hemodynamically optimal (defined by AHR equal to, or within 5% of, the largest dp/dt response) in 35 of 40 patients (88%). Sites with the longest RV-LV and narrowest paced QRS were hemodynamically optimal in 26 of 40 patients (65%) and 28 of 40 patients (70%), respectively. EH metrics from isochronal maps had much better accuracy (sensitivity 90%, specificity 80%) for identifying hemodynamically responsive sites (∆LV dp/dtmax≥10%) compared with RV-LV delay (69%, 85%) or paced QRS reduction (52%, 76%). Multivariate prediction model based on EH metrics showed significant correlation (R2= 0.53, P <.001) between predicted and measured AHR.
  
  
  
  Changes in EH from baseline to BiV pacing more accurately identified hemodynamically optimal sites than RV-LV delays or paced QRS shortening. Optimization of LV lead location by minimizing EH during BiV pacing, based on body surface mapping, may improve CRT response.
authors.affiliation: Iowa Heart Center PC, Des Moines, Iowa.
authors.forename: W Ben
authors.initials: WB
authors.lastname: Johnson
authors.affiliation: United Heart and Vascular Clinic, St. Paul, Minnesota.
authors.forename: Pierce J
authors.initials: PJ
authors.lastname: Vatterott
authors.affiliation: United Heart and Vascular Clinic, St. Paul, Minnesota.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Peterson
authors.affiliation: United Heart and Vascular Clinic, St. Paul, Minnesota.
authors.forename: Suveer
authors.initials: S
authors.lastname: Bagwe
authors.affiliation: United Heart and Vascular Clinic, St. Paul, Minnesota.
authors.forename: R Dent
authors.initials: RD
authors.lastname: Underwood
authors.affiliation: United Heart and Vascular Clinic, St. Paul, Minnesota.
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Bank
authors.affiliation: United Heart and Vascular Clinic, St. Paul, Minnesota.
authors.forename: Ryan M
authors.initials: RM
authors.lastname: Gage
authors.affiliation: St Luke's Mid America Heart Institute, Kansas City, Missouri.
authors.forename: Brian
authors.initials: B
authors.lastname: Ramza
authors.affiliation: Cardiovascular Medicine PC, Davenport, Iowa.
authors.forename: Blair W
authors.initials: BW
authors.lastname: Foreman
authors.affiliation: Medtronic PLC, MoundsView, Minnesota.
authors.forename: Vincent
authors.initials: V
authors.lastname: Splett
authors.affiliation: Medtronic PLC, MoundsView, Minnesota.
authors.forename: Tarek
authors.initials: T
authors.lastname: Haddad
authors.affiliation: Medtronic PLC, MoundsView, Minnesota.
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Gillberg
authors.affiliation: Medtronic PLC, MoundsView, Minnesota. Electronic address: subham.ghosh@medtronic.com.
authors.forename: Subham
authors.initials: S
authors.lastname: Ghosh
mesh_terms: D000368:Aged; D018780:Body Surface Potential Mapping; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D058409:Cardiac Resynchronization Therapy Devices; D005260:Female; D006333:Heart Failure / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy; D006352:Heart Ventricles / Q000503:physiopathology; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D010043:Outcome and Process Assessment, Health Care; D017755:Prosthesis Fitting / Q000379:methods; D058996:Quality Improvement; D016277:Ventricular Function, Left
keywords: Acute hemodynamic response; Body surface mapping; Cardiac resynchronization therapy