title: Changes of pulmonary vein orifice size and location throughout the cardiac cycle: dynamic analysis using magnetic resonance cine imaging.
abstract: BACKGROUND
  Anatomically guided left atrial ablation is used increasingly for treatment of atrial fibrillation (AF). Three-dimensional mapping systems used for pulmonary veins (PV) encircling ablation procedures anticipate a stable size and position of the PV orifice. The aim of the current study was therefore to analyze changes of PV orifice size and location throughout the cardiac cycle using cine magnetic resonance imaging (MRI).
  
  
  RESULTS
  Twenty-five healthy volunteers were studied using a 1.5 Tesla MRI system. MR angiograms were acquired with a breath-hold three-dimensional fast-spoiled gradient-echo imaging (3D FSPGR) sequence in the coronal plane before and after gadolinium injection. Maximum intensity projections and multiplanar reformations were performed to reconstruct images of the PV. Bright blood cine imaging in the axial view was acquired by a steady-state free precession pulse sequence. Twenty bright blood images were obtained per cardiac cycle. The axial (anterior-posterior) PV orifice diameter was measured in all 20 images. For analysis of PV movement the location of the orifice posterior edge was plotted on scale paper. PV orifice size depends on the stage of the cardiac cycle with the largest diameter in late atrial diastole and a mean decrease of 32.5% during atrial systole. Location changes of the PV orifice are in the range of up to 7.2 mm and larger in the coronal (lateral-medial) than in the sagittal (anterior-posterior) direction.
  
  
  CONCLUSIONS
  PV orifice size and location is not as stable as anticipated by three-dimensional mapping systems used for PV encircling left atrial ablation procedures. RF application close to the presumed orifice location should therefore be avoided to minimize the risk of PV stenosis.
authors.affiliation: Division of Cardiology, The John Hopkins University, Baltimore, Maryland, USA. lars.lickfett@ukb.uni-bonn.de
authors.forename: Lars
authors.initials: L
authors.lastname: Lickfett
authors.forename: Timm
authors.initials: T
authors.lastname: Dickfeld
authors.forename: Ritsushi
authors.initials: R
authors.lastname: Kato
authors.forename: Harikrishna
authors.initials: H
authors.lastname: Tandri
authors.forename: Chandrasekhar R
authors.initials: CR
authors.lastname: Vasamreddy
authors.forename: Ronald
authors.initials: R
authors.lastname: Berger
authors.forename: David
authors.initials: D
authors.lastname: Bluemke
authors.forename: Berndt
authors.initials: B
authors.lastname: Lüderitz
authors.forename: Henry
authors.initials: H
authors.lastname: Halperin
authors.forename: Hugh
authors.initials: H
authors.lastname: Calkins
mesh_terms: D000328:Adult; D001281:Atrial Fibrillation; D016275:Atrial Function / Q000502:physiology*; D017115:Catheter Ablation; D003287:Contrast Media; D017023:Coronary Angiography; D005260:Female; D005682:Gadolinium; D006801:Humans; D021621:Imaging, Three-Dimensional; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D008953:Models, Anatomic; D008962:Models, Theoretical; D011446:Prospective Studies; D011667:Pulmonary Veins / Q000033:anatomy & histology* / Q000502:physiology*; D013997:Time Factors
chemical_list: D003287:Contrast Media; D005682:Gadolinium