title: Analysis of Left Atrial Respiratory and Cardiac Motion for Cardiac Ablation Therapy.
abstract: Cardiac ablation therapy is often guided by models built from preoperative computed tomography (CT) or magnetic resonance imaging (MRI) scans. One of the challenges in guiding a procedure from a preoperative model is properly synching the preoperative models with cardiac and respiratory motion through computational motion models. In this paper, we describe a methodology for evaluating cardiac and respiratory motion in the left atrium and pulmonary veins of a beating canine heart. Cardiac catheters were used to place metal clips within and near the pulmonary veins and left atrial appendage under fluoroscopic and ultrasound guidance and a contrast-enhanced, 64-slice multidetector CT scan was collected with the clips in place. Each clip was segmented from the CT scan at each of the five phases of the cardiac cycle at both end-inspiration and end-expiration. The centroid of each segmented clip was computed and used to evaluate both cardiac and respiratory motion of the left atrium. A total of three canine studies were completed, with 4 clips analyzed in the first study, 5 clips in the second study, and 2 clips in the third study. Mean respiratory displacement was 0.2±1.8mmin the medial/lateral direction, 4.7±4.4mmin the anterior/posterior direction (moving anterior on inspiration), and 9.0±5.0mmsuperior/inferior (moving inferior with inspiration). At end inspiration, the mean left atrial cardiac motion at the clip locations was 1.5±1.3mmin the medial/lateral direction, and 2.1±2.0mmin the anterior/posterior and 1.3±1.2mmsuperior/inferior directions. At end expiration, the mean left atrial cardiac motion at the clip locations was 2.0±1.5mmin the medial/lateral direction, 3.0±1.8mmin the anterior/posterior direction, and 1.5±1.5mmin the superior/inferior directions.
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota, 55905, USA.
authors.forename: M E
authors.initials: ME
authors.lastname: Rettmann
authors.affiliation: Biomedical Imaging Resource, Mayo Clinic, Rochester, Minnesota, 55905, USA.
authors.forename: D R
authors.initials: DR
authors.lastname: Holmes
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota, 55905, USA.
authors.forename: S B
authors.initials: SB
authors.lastname: Johnson
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota, 55905, USA.
authors.forename: H I
authors.initials: HI
authors.lastname: Lehmann
authors.affiliation: Biomedical Imaging Resource, Mayo Clinic, Rochester, Minnesota, 55905, USA.
authors.forename: R A
authors.initials: RA
authors.lastname: Robb
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota, 55905, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Packer