title: Nuclear image-guided left ventricular pacing lead navigation feasibility of a new technique.
abstract: OBJECTIVE
  Current techniques for left ventricular (LV) lead implantation in patients with ischemic cardiomyopathy (ICM) typically underutilize information which is important for optimal lead location, including LV mechanical activation pattern and scar location. We sought to develop a technique in which this information, contained in single-photon emission computed tomographic (SPECT) images, could be integrated as to guide the electrophysiologist during the implantation procedure.
  
  
  METHODS
  Five ICM patients underwent SPECT as well as multidetector cardiac computed tomographic (MDCT) imaging prior to the LV lead implantation procedure. Images were merged to create a "fusion" image, in which the SPECT data were projected onto the anatomically accurate MDCT epicardial surface. The fusion image was registered to the operative field using the coronary veins, apparent on the MDCT image, as a fiducial system. After registration, LV lead implantation was guided by the fusion image using a commercial catheter navigation system.
  
  
  RESULTS
  Successful guidance was achieved in each patient, with minimal disturbance to standard workflow. Leads were implanted in late-activating, unscarred regions according to the fusion image, with locations corroborated by fluoroscopic and electrographic features. In regions where leads were contiguous to the phrenic nerve shown on the fusion image, pacing consistently demonstrated diaphragmatic stimulation.
  
  
  CONCLUSIONS
  In this technical report, the description and feasibility of a new technique for SPECT image-guided LV pacing lead navigation is demonstrated. Prospective study will be required to confirm image precision and registration/navigation accuracy, as well as to demonstrate value relative to standard implantation techniques.
authors: Division of Radiology, University of Pittsburgh, Pittsburgh, PA, USA.
authors: Daniel R
authors: DR
authors: Ludwig
authors: QuantMD, LLC, Pittsburgh, PA, USA.
authors: Prahlad G
authors: PG
authors: Menon
authors: Heart, Lung and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA. schwartzmand@upmc.edu.
authors: David
authors: D
authors: Schwartzman
mesh_terms: D000368:Aged; D004567:Electrodes, Implanted; D005240:Feasibility Studies; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000000981:diagnostic imaging / Q000517:prevention & control*; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D019919:Prosthesis Implantation / Q000379:methods; D025321:Surgery, Computer-Assisted / Q000379:methods*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D016896:Treatment Outcome
keywords: Cardiac resynchronization therapy; Computed tomography; Heart failure; Image guidance; Pacing; Single-photon emission computed tomography