title: Electroanatomic mapping of the left ventricle in a porcine model of chronic myocardial infarction with magnetic resonance-based catheter tracking.
abstract: BACKGROUND
  X-ray fluoroscopy constitutes the fundamental imaging modality for catheter visualization during interventional electrophysiology procedures. The minimal tissue discriminative capability of fluoroscopy is mitigated in part by the use of electroanatomic mapping systems and enhanced by the integration of preacquired 3-dimensional imaging of the heart with computed tomographic or magnetic resonance (MR) imaging. A more ideal paradigm might be to use intraprocedural MR imaging to directly image and guide catheter mapping procedures.
  
  
  RESULTS
  An MR imaging-based electroanatomic mapping system was designed to assess the feasibility of navigating catheters to the left ventricle in vivo using MR tracking of microcoils incorporated into the catheters, measuring intracardiac ventricular electrograms, and integrating this information with 3-dimensional MR angiography and myocardial delayed enhancement images to allow ventricular substrate mapping. In all animals (4 normal, and 10 chronically infarcted swine), after transseptal puncture under fluoroscopic guidance, catheters were successfully navigated to the left ventricle with MR tracking (13 to 15 frames per second) by both transseptal and retrograde aortic approaches. Electrogram artifacts related to the MR imaging gradient pulses were successfully removed with analog and digital signal processing. In all animals, it was possible to map the entire left ventricle and to project electrogram voltage amplitude maps to identify the scarred myocardium.
  
  
  CONCLUSIONS
  It is possible to use MR tracking to navigate catheters to the left ventricle, to measure electrogram activity, and to render accurate 3-dimensional voltage maps in a porcine model of chronic myocardial infarction, completely in the MR imaging environment. Myocardial delayed enhancement guidance provided dense sampling of the proximity of the infarct and accurate localization of complex infarcts.
authors.affiliation: Cardiac Arrhythmia Service, Massachusetts General Hospital and Harvard Medical School, Boston, Mass., USA.
authors.forename: Srinivas R
authors.initials: SR
authors.lastname: Dukkipati
authors.forename: Richard
authors.initials: R
authors.lastname: Mallozzi
authors.forename: Ehud J
authors.initials: EJ
authors.lastname: Schmidt
authors.forename: Godtfred
authors.initials: G
authors.lastname: Holmvang
authors.forename: Andre
authors.initials: A
authors.lastname: d'Avila
authors.forename: Renee
authors.initials: R
authors.lastname: Guhde
authors.forename: Robert D
authors.initials: RD
authors.lastname: Darrow
authors.forename: Glenn
authors.initials: G
authors.lastname: Slavin
authors.forename: Maggie
authors.initials: M
authors.lastname: Fung
authors.forename: Zachary
authors.initials: Z
authors.lastname: Malchano
authors.forename: Greg
authors.initials: G
authors.lastname: Kampa
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Dando
authors.forename: Christina
authors.initials: C
authors.lastname: McPherson
authors.forename: Thomas K
authors.initials: TK
authors.lastname: Foo
authors.forename: Jeremy N
authors.initials: JN
authors.lastname: Ruskin
authors.forename: Charles L
authors.initials: CL
authors.lastname: Dumoulin
authors.forename: Vivek Y
authors.initials: VY
authors.lastname: Reddy
mesh_terms: D000818:Animals; D017115:Catheter Ablation / Q000379:methods; D002404:Catheterization / Q000009:adverse effects / Q000379:methods; D004195:Disease Models, Animal; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods*; D006352:Heart Ventricles / Q000473:pathology / Q000503:physiopathology*; D008012:Lidocaine / Q000627:therapeutic use; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009203:Myocardial Infarction / Q000473:pathology* / Q000503:physiopathology; D013552:Swine; D017180:Tachycardia, Ventricular / Q000209:etiology / Q000517:prevention & control
chemical_list: D008012:Lidocaine