title: Association of Left Atrial Local Conduction Velocity With Late Gadolinium Enhancement on Cardiac Magnetic Resonance in Patients With Atrial Fibrillation.
abstract: BACKGROUND
  Prior studies have demonstrated regional left atrial late gadolinium enhancement (LGE) heterogeneity on magnetic resonance imaging. Heterogeneity in regional conduction velocities is a critical substrate for functional reentry. We sought to examine the association between left atrial conduction velocity and LGE in patients with atrial fibrillation.
  
  
  RESULTS
  LGE imaging and left atrial activation mapping were performed during sinus rhythm in 22 patients before pulmonary vein isolation. The locations of 1468 electroanatomic map points were registered to the corresponding anatomic sites on 469 axial LGE image planes. The local conduction velocity at each point was calculated using previously established methods. The myocardial wall thickness and image intensity ratio defined as left atrial myocardial LGE signal intensity divided by the mean left atrial blood pool intensity was calculated for each mapping site. The local conduction velocity and image intensity ratio in the left atrium (mean ± SD) were 0.98 ± 0.46 and 0.95 ± 0.26 m/s, respectively. In multivariable regression analysis, clustered by patient, and adjusting for left atrial wall thickness, conduction velocity was associated with the local image intensity ratio (0.20 m/s decrease in conduction velocity per increase in unit image intensity ratio, P<0.001).
  
  
  CONCLUSIONS
  In this clinical in vivo study, we demonstrate that left atrial myocardium with increased gadolinium uptake has lower local conduction velocity. Identification of such regions may facilitate the targeting of the substrate for reentrant arrhythmias.
authors.affiliation: From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD.
authors.forename: Kotaro
authors.initials: K
authors.lastname: Fukumoto
authors.affiliation: From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD.
authors.forename: Mohammadali
authors.initials: M
authors.lastname: Habibi
authors.affiliation: From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD.
authors.forename: Esra Gucuk
authors.initials: EG
authors.lastname: Ipek
authors.affiliation: From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD.
authors.forename: Sohail
authors.initials: S
authors.lastname: Zahid
authors.affiliation: From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD.
authors.forename: Irfan M
authors.initials: IM
authors.lastname: Khurram
authors.affiliation: From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD.
authors.forename: Stefan L
authors.initials: SL
authors.lastname: Zimmerman
authors.affiliation: From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD.
authors.forename: Vadim
authors.initials: V
authors.lastname: Zipunnikov
authors.affiliation: From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD.
authors.forename: David
authors.initials: D
authors.lastname: Spragg
authors.affiliation: From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ashikaga
authors.affiliation: From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD.
authors.forename: Natalia
authors.initials: N
authors.lastname: Trayanova
authors.affiliation: From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD.
authors.forename: Gordon F
authors.initials: GF
authors.lastname: Tomaselli
authors.affiliation: From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD.
authors.forename: John
authors.initials: J
authors.lastname: Rickard
authors.affiliation: From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD.
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Marine
authors.affiliation: From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD.
authors.forename: Ronald D
authors.initials: RD
authors.lastname: Berger
authors.affiliation: From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD.
authors.forename: Hugh
authors.initials: H
authors.lastname: Calkins
authors.affiliation: From the Section of Cardiac Electrophsyiology (K.F., M.H., E.G.I., I.M.K., D.S., H.A., N.T., G.F.T., J.R., J.E.M., R.D.B., H.C., S.N.), Department of Biomedical Engineering (S.Z., H.A., N.T., R.D.B.), Department of Radiology (S.L.Z.), Department of Biostatistics (V.Z.), and Department of Epidemiology (S.N.), Johns Hopkins University, Baltimore, MD. snazarian@jhmi.edu.
authors.forename: Saman
authors.initials: S
authors.lastname: Nazarian
mesh_terms: D000200:Action Potentials; D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D016279:Atrial Function, Left; D003287:Contrast Media / Q000008:administration & dosage*; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D019786:Gadolinium DTPA / Q000008:administration & dosage*; D006325:Heart Atria / Q000473:pathology / Q000503:physiopathology; D006329:Heart Conduction System / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007700:Kinetics; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D015203:Reproducibility of Results
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA
keywords: arrhythmias, cardiac; atrial fibrillation; fibrosis; magnetic resonance imaging; regression analysis