title: Assessment of left and right atrial 3D hemodynamics in patients with atrial fibrillation: a 4D flow MRI study.
abstract: Atrial fibrillation (AF) is associated with embolic stroke due to thrombus formation in the left atrium (LA). Based on the relationship of atrial stasis to thromboembolism and the marked disparity in pulmonary versus systemic thromboembolism in AF, we tested the hypothesis that flow velocity distributions in the left (LA) versus right atrium (RA) in patients with would demonstrate increased stasis. Whole heart 4D flow MRI was performed in 62 AF patients (n = 33 in sinus rhythm during imaging, n = 29 with persistent AF) and 8 controls for the assessment of in vivo atrial 3D blood flow. 3D segmentation of the LA and RA geometry and normalized velocity histograms assessed atrial velocity distribution and stasis (% of atrial velocities <0.2 m/s). Atrial hemodynamics were similar for RA and LA and significantly correlated (mean velocity: r = 0.64; stasis: r = 0.55, p < 0.001). RA and LA mean and median velocities were lower in AF patients by 15-33 % and stasis was elevated by 11-19 % compared to controls. There was high inter-individual variability in LA/RA mean velocity ratio (range 0.5-1.8) and LA/RA stasis ratio (range 0.7-1.7). Patients with a history of AF and in sinus rhythm showed most pronounced differences in atrial flow (reduced mean velocities, higher stasis in the LA). While there is no systematic difference in LA versus RA flow velocity profiles, high variability was noted. Further delineation of patient specific factors and/or regional atrial effects on the LA and RA flow velocity profiles, as well as other factors such as differences in procoagulant factors, may explain the more prevalent systemic versus pulmonary thromboembolism in patients with AF.
authors.affiliation: Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Avenue Suite 1600, Chicago, IL, 60611, USA. mmarkl@northwestern.edu.|Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, USA. mmarkl@northwestern.edu.
authors.forename: Michael
authors.initials: M
authors.lastname: Markl
authors.affiliation: Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Avenue Suite 1600, Chicago, IL, 60611, USA.
authors.forename: Maria
authors.initials: M
authors.lastname: Carr
authors.affiliation: Division of Cardiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.|Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
authors.forename: Jason
authors.initials: J
authors.lastname: Ng
authors.affiliation: Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Avenue Suite 1600, Chicago, IL, 60611, USA.|Division of Cardiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.|Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Lee
authors.affiliation: Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Avenue Suite 1600, Chicago, IL, 60611, USA.|Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, USA.
authors.forename: Kelly
authors.initials: K
authors.lastname: Jarvis
authors.affiliation: Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Avenue Suite 1600, Chicago, IL, 60611, USA.
authors.forename: James
authors.initials: J
authors.lastname: Carr
authors.affiliation: Division of Cardiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.|Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.|Center for Cardiovascular Innovation, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Goldberger
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016279:Atrial Function, Left; D016280:Atrial Function, Right; D001783:Blood Flow Velocity; D005260:Female; D006439:Hemodynamics; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D011379:Prognosis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012307:Risk Factors; D013923:Thromboembolism / Q000209:etiology / Q000503:physiopathology
keywords: 4D flow MRI; Atrial fibrillation; Blood flow; Stasis; Thromboembolism
references.citation: Chest. 2008 Jun;133(6 Suppl):546S-592S
references.pmid: 18574273
references.citation: Arch Intern Med. 1995 Mar 13;155(5):469-73
references.pmid: 7864703
references.citation: J Am Coll Cardiol. 1995 May;25(6):1354-61
references.pmid: 7722133
references.citation: Jpn Heart J. 2000 Jul;41(4):451-62
references.pmid: 11041096
references.citation: J Magn Reson Imaging. 2013 Sep;38(3):580-7
references.pmid: 23292793
references.citation: Ann Intern Med. 1997 Feb 1;126(3):200-9
references.pmid: 9027270
references.citation: Ann Intern Med. 1998 Apr 15;128(8):639-47
references.pmid: 9537937
references.citation: J Am Coll Cardiol. 1994 Sep;24(3):755-62
references.pmid: 8077549
references.citation: J Am Coll Cardiol. 2005 Jun 7;45(11):1807-12
references.pmid: 15936610
references.citation: Clin Appl Thromb Hemost. 2010 Apr;16(2):218-20
references.pmid: 18840628
references.citation: Circulation. 2002 Nov 26;106(22):2854-8
references.pmid: 12451014
references.citation: Stroke. 2001 May;32(5):1127-33
references.pmid: 11340221
references.citation: Echocardiography. 2000 Aug;17 (6 Pt 1):555-62
references.pmid: 11000590
references.citation: J Am Coll Cardiol. 2012 Aug 7;60(6):531-8
references.pmid: 22858289
references.citation: Invest Radiol. 2016 Mar;51(3):147-54
references.pmid: 26488375
references.citation: Eur Heart J Cardiovasc Imaging. 2016 Nov;17 (11):1259-1268
references.pmid: 26590397
references.citation: N Engl J Med. 2009 Sep 17;361(12):1139-51
references.pmid: 19717844
references.citation: N Engl J Med. 1993 Mar 18;328(11):750-5
references.pmid: 8437595
references.citation: J Am Soc Echocardiogr. 1999 Dec;12 (12 ):1080-7
references.pmid: 10588784
references.citation: Am J Cardiol. 1999 Nov 1;84(9):1023-8
references.pmid: 10569657
references.citation: N Engl J Med. 2001 May 10;344(19):1411-20
references.pmid: 11346805
references.citation: J Am Soc Echocardiogr. 2005 Dec;18(12 ):1366-72
references.pmid: 16376768
references.citation: Lancet. 2009 Jan 10;373(9658):155-66
references.pmid: 19135613
references.citation: J Am Soc Echocardiogr. 2006 Apr;19(4):429-33
references.pmid: 16581482
references.citation: J Comput Assist Tomogr. 2015 May-Jun;39(3):422-7
references.pmid: 25978593
references.citation: J Am Coll Cardiol. 1994 Mar 15;23 (4):961-9
references.pmid: 8106703
references.citation: J Magn Reson Imaging. 2007 Apr;25(4):824-31
references.pmid: 17345635