title: Mapping-guided characterization of mechanical and electrical activation patterns in patients with normal systolic function using a sensor-based tracking technology.
abstract: OBJECTIVE
  In times of evolving cardiac resynchronization therapy, intra-procedural characterization of left ventricular (LV) mechanical activation patterns is desired but technically challenging with currently available technologies. In patients with normal systolic function, we evaluated the feasibility of characterizing LV wall motion using a novel sensor-based, real-time tracking technology.
  
  
  RESULTS
  Ten patients underwent simultaneous motion and electrical mapping of the LV endocardium during sinus rhythm using electroanatomical mapping and navigational systems (EnSite™ NavX™ and MediGuide™, SJM). Epicardial motion data were also collected simultaneously at corresponding locations from accessible coronary sinus branches. Displacements at each mapping point and times of electrical and mechanical activation were combined over each of the six standard LV wall segments. Mechanical activation timing was compared with that from electrical activation and preoperative 2D speckle tracking echocardiography (echo). MediGuide-based displacement data were further analysed to estimate LV chamber volumes that were compared with echo and magnetic resonance imaging (MRI). The lateral and septal walls exhibited the largest (12.5 [11.6-15.0] mm) and smallest (10.2 [9.0-11.3] mm) displacement, respectively. Radial displacement was significantly larger endocardially than epicardially (endo: 6.7 [5.0-9.1] mm; epi: 3.8 [2.4-5.6] mm), while longitudinal displacement was significantly larger epicardially (endo: 8.0 [5.0-10.6] mm; epi: 10.3 [7.4-13.8] mm). Most often, the anteroseptal/anterior and lateral walls showed the earliest and latest mechanical activations, respectively. 9/10 patients had concordant or adjacent wall segments of latest mechanical and electrical activation, and 6/10 patients had concordant or adjacent wall segments of latest mechanical activation as measured by MediGuide and echo. MediGuide's LV chamber volumes were significantly correlated with MRI (R2= 0.73, P < 0.01) and echo (R2= 0.75, P < 0.001).
  
  
  CONCLUSIONS
  The feasibility of mapping-guided intra-procedural characterization of LV wall motion was established.
  
  
  BACKGROUND
  http://www.clinicaltrials.gov; Unique identifier: CT01629160.
authors.affiliation: Department of Invasive Electrophysiology, University of Dresden-Heart Center, Dresden, Germany.
authors.forename: Christopher
authors.initials: C
authors.lastname: Piorkowski
authors.affiliation: Department of Electrophysiology, University of Leipzig-Heart Center, Leipzig, Germany.
authors.forename: Ole-A
authors.initials: OA
authors.lastname: Breithardt
authors.affiliation: St Jude Medical, Sylmar, CA, USA.
authors.forename: Hedi
authors.initials: H
authors.lastname: Razavi
authors.affiliation: St Jude Medical, Sylmar, CA, USA.
authors.forename: Yelena
authors.initials: Y
authors.lastname: Nabutovsky
authors.affiliation: St Jude Medical, Sylmar, CA, USA.
authors.forename: Stuart P
authors.initials: SP
authors.lastname: Rosenberg
authors.affiliation: St Jude Medical, Sylmar, CA, USA.
authors.forename: Craig D
authors.initials: CD
authors.lastname: Markovitz
authors.affiliation: Department of Electrophysiology, University of Leipzig-Heart Center, Leipzig, Germany.
authors.forename: Arash
authors.initials: A
authors.lastname: Arya
authors.affiliation: Department of Electrophysiology, University of Leipzig-Heart Center, Leipzig, Germany.
authors.forename: Sascha
authors.initials: S
authors.lastname: Rolf
authors.affiliation: Department of Electrophysiology, University of Leipzig-Heart Center, Leipzig, Germany.
authors.forename: Silke
authors.initials: S
authors.lastname: John
authors.affiliation: Department of Electrophysiology, University of Leipzig-Heart Center, Leipzig, Germany.
authors.forename: Jedrzej
authors.initials: J
authors.lastname: Kosiuk
authors.affiliation: St Jude Medical, St Paul, MN, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Olson
authors.affiliation: Department of Electrophysiology, University of Leipzig-Heart Center, Leipzig, Germany.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Eitel
authors.affiliation: Department of Invasive Electrophysiology, University of Dresden-Heart Center, Dresden, Germany.
authors.forename: Yan
authors.initials: Y
authors.lastname: Huo
authors.affiliation: Department of Electrophysiology, University of Leipzig-Heart Center, Leipzig, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Döring
authors.affiliation: Department of Electrophysiology, University of Leipzig-Heart Center, Leipzig, Germany.
authors.forename: Sergio
authors.initials: S
authors.lastname: Richter
authors.affiliation: St Jude Medical, Sylmar, CA, USA.
authors.forename: Kyungmoo
authors.initials: K
authors.lastname: Ryu
authors.affiliation: Department of Invasive Electrophysiology, University of Dresden-Heart Center, Dresden, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Gaspar
authors.affiliation: Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, Netherlands.
authors.forename: Frits W
authors.initials: FW
authors.lastname: Prinzen
authors.affiliation: Department of Electrophysiology, University of Leipzig-Heart Center, Leipzig, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Hindricks
authors.affiliation: Department of Electrophysiology, University of Leipzig-Heart Center, Leipzig, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Sommer
mesh_terms: D000200:Action Potentials; D000368:Aged; D004452:Echocardiography; D055590:Electromagnetic Phenomena; D022062:Electrophysiologic Techniques, Cardiac; D004867:Equipment Design; D005240:Feasibility Studies; D005260:Female; D006339:Heart Rate; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000295:instrumentation* / Q000379:methods; D010865:Pilot Projects; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013318:Stroke Volume; D013599:Systole; D013686:Telemetry / Q000295:instrumentation* / Q000379:methods; D013997:Time Factors; D014159:Transducers; D016277:Ventricular Function, Left
keywords: Electromagnetic navigation; Magnetic resonance imaging; MediGuide; Speckle tracking echocardiography