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Aortic Flow

The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform

Nobuyuki Ohte – 1st expert on this subject based on the ideXlab platform

  • Noninvasive Evaluation of the Inertia Force of Late Systolic Aortic Flow
    IFMBE Proceedings, 2020
    Co-Authors: Nobuyuki Ohte, Kazuaki Wakami, Motoaki Sugawara, Kiyomi Niki, Genjiro Kimura

    Abstract:

    The inertia force of late systolic Aortic Flow, which is generated by left ventricles with good contraction, may be a crucial parameter through which good left ventricular (LV) systolic function delivers its effect on LV early diastolic performance. We attempted to find noninvasive parameters of the inertia force using 2-dimensional ultrasound speckle tracking imaging of the left ventricle and wave intensity (WI) analysis at the right carotid artery. The LV strain along the long-axis at end-systole had significant correlations with both the LV ejection fraction (r=0.80, p

  • abstract 18465 the kinetic energy of left ventricular ejection Flow during late systole produces inertia force of late systolic Aortic Flow and good left ventricular early diastolic function
    Circulation, 2016
    Co-Authors: Junki Yamamoto, Kazuaki Wakami, Toshihiko Goto, Hiroshi Fujita, Shohei Kikuchi, Syunsuke Murai, Tomonori Sugiura, Nobuyuki Ohte

    Abstract:

    Background: Inertia force of late systolic Aortic Flow (IF), which plays a substantial role for the coupling between left ventricular (LV) contraction and relaxation, may depend on the kinetic energy of ejecting Flow (KE) during late systole (KE-LS). Good LV contraction generated much greater KE during early systole (KE-ES) and the KE-ES should affect the KE-LS. We investigated whether the KE-ES and -LS obtained using Vector Flow Mapping (VFMTM, Hitachi-Aloka) had any relationships with both IF and LV relaxation parameters invasively obtained. Method: Study subjects were 30 patients who underwent diagnostic cardiac catheterization and echocardiography on the same day. Conventional color Doppler images were acquired in the apical 3-chamber view. KE was obtained using the commercially available software (Hitachi-Aloka) (Figure). We divided the LV ejection time into 3 equal phases, then the KE was computed as a sum of KE values frame by frame basis around ES and LS; The ES was defined as the first one-third …

  • abstract 12333 do the patients with inertia force of late systolic Aortic Flow have less incidence of heart failure
    Circulation, 2013
    Co-Authors: Toshihiko Goto, Kazuaki Wakami, Takafumi Kato, Hachiya Kenta, Hiroshi Fujita, Tomomitsu Tani, Nobuyuki Ohte

    Abstract:

    Inertia force of late systolic Aortic Flow (IF) is observed in the left ventricles (LV) with good systolic function. A lack of IF provokes isolated LV diastolic dysfunction and may be related to th…

Chris S Malaisrie – 2nd expert on this subject based on the ideXlab platform

  • viscous energy loss in the presence of abnormal Aortic Flow
    Magnetic Resonance in Medicine, 2014
    Co-Authors: Alex J. Barker, James C. Carr, Pim Van Ooij, Krishna C Bandi, Julio Garcia, Mazen Albaghdadi, Patrick M Mccarthy, Robert O Bonow, Jeremy D Collins, Chris S Malaisrie

    Abstract:

    Purpose

    To present a theoretical basis for noninvasively characterizing in vivo fluid-mechanical energy losses and to apply it in a pilot study of patients known to express abnormal Aortic Flow patterns.

    Methods

    Four-dimensional Flow MRI was used to characterize laminar viscous energy losses in the aorta of normal controls (n = 12, age = 37 ± 10 yr), patients with Aortic dilation (n = 16, age = 52 ± 8 yr), and patients with Aortic valve stenosis matched for age and Aortic size (n = 14, age = 46 ± 15 yr), using a relationship between the three-dimensional velocity field and viscous energy dissipation.

    Results

    Viscous energy loss was elevated significantly in the thoracic aorta in patients with dilated aorta (3.6 ± 1.3 mW, P = 0.024) and patients with Aortic stenosis (14.3 ± 8.2 mW, P < 0.001) compared with healthy volunteers (2.3 ± 0.9 mW). The same pattern of significant differences was seen in the ascending aorta, where viscous energy losses in patients with dilated aortas (2.2 ± 1.1 mW, P = 0.021) and patients with Aortic stenosis (10.9 ± 6.8 mW, P < 0.001) were elevated compared with healthy volunteers (1.2 ± 0.6 mW). Conclusion This technique provides a capability to quantify the contribution of abnormal laminar blood Flow to increased ventricular afterload. In this pilot study, viscous energy loss in patient cohorts was significantly elevated and indicates that cardiac afterload is increased due to abnormal Flow. Magn Reson Med 72:620–628, 2014. © 2013 Wiley Periodicals, Inc.

Alex J. Barker – 3rd expert on this subject based on the ideXlab platform

  • Increased systolic vorticity in the left ventricular outFlow tract is associated with abnormal Aortic Flow formations in Tetralogy of Fallot.
    International Journal of Cardiovascular Imaging, 2020
    Co-Authors: Michal Schäfer, Alex J. Barker, James Jaggers, Gareth J. Morgan, Matthew L. Stone, Lorna P. Browne, Max B. Mitchell

    Abstract:

    : Aortopathy is a recognized comorbidity of Tetralogy of Fallot (TOF). Aortic Flow in children with repaired TOF is abnormal despite normal Aortic valve anatomy and early surgical repair that results in Aortic size normalization. The purpose of this study was to investigate the Flow hemodynamics inside the left ventricle (LV) of children with repaired TOF using 4D-Flow MRI derived vorticity. Vorticity is the spatial derivative of Flow velocity and is sensitive to anatomic and geometric variations. Vorticity was calculated inside the LV of children with repaired TOF having normal Aortic size (n = 14) and normal controls (n = 10) during systolic ejection phase. All subjects underwent comprehensive biventricular analysis including the MRI based feature-tracking based LV strain analysis and mechanical dyssynchrony. Right ventricular (RV) volumetric indices along with LV mechanical indices were correlated with LV vorticity. All TOF patients had supraphysiologic helical Flow in the ascending aorta. The generated peak systolic vorticity integrated over the LV volume was elevated in TOF group compared to control (median: 1344 vs. 858 s-1, P 

  • Abnormal Aortic Flow conduction is associated with increased viscous energy loss in patients with repaired tetralogy of Fallot.
    European Journal of Cardio-Thoracic Surgery, 2019
    Co-Authors: Michal Schäfer, Alex J. Barker, James Jaggers, Gareth J. Morgan, Matthew L. Stone, Uyen Truong, Lorna P. Browne, Ladonna Malone, Max B. Mitchell

    Abstract:

    Objectives Aortopathy in tetralogy of Fallot (TOF) is characterized by increased Aortic stiffness, dilation and reduced left ventricular (LV) function. Repair in infancy normalizes Aortic dimensions in early childhood. Our prior work demonstrated that early TOF repair does not normalize Aortic compliance and that abnormal ascending Aortic Flow patterns are prevalent. The objectives of this study were to: (i) determine whether proximal Aortic Flow-mediated viscous energy loss (EL’) is elevated in patients with early TOF repair compared with healthy controls, and (ii) determine whether the degree of EL’ is associated with LV function. Methods Forty-one patients post TOF repair with normalized Aortic size and 15 healthy controls underwent 4-dimenisonal-Flow magnetic resonance imaging Flow analysis and EL’ assessment. Correlations between EL’, Aortic size, and LV function were assessed. Results The TOF group had increased peak systolic thoracic aorta EL’ (3.8 vs 1.5 mW, P = 0.004) and increased averaged EL’ throughout the cardiac cycle (1.2 vs 0.5 mW, P = 0.003). Peak and mean systolic EL’ in the ascending aorta was increased 2-fold in the TOF group compared with control (peak: 2.0 vs 0.9 mW, P = 0.007). Peak EL’ measured along the entire thoracic Aortic length correlated with LV ejection fraction (R = -0.45, P = 0.009), indexed LV end-systolic volume (R = -0.40, P = 0.010), and right ventricular end-systolic volume (R = -0.37, P = 0.034). Conclusions Patients with repaired TOF exhibit abnormal Aortic Flow associated with increased EL’ in the thoracic aorta. The magnitude of EL’ is associated with LV function and volumes. Increased Aortic EL’ in TOF is likely due to inherently abnormal LV outFlow geometry and or right ventricular interaction. Reduced Aortic Flow efficiency in TOF increases cardiac work and may be an important factor in long-term cardiac performance.

  • viscous energy loss in the presence of abnormal Aortic Flow
    Magnetic Resonance in Medicine, 2014
    Co-Authors: Alex J. Barker, James C. Carr, Pim Van Ooij, Krishna C Bandi, Julio Garcia, Mazen Albaghdadi, Patrick M Mccarthy, Robert O Bonow, Jeremy D Collins, Chris S Malaisrie

    Abstract:

    Purpose

    To present a theoretical basis for noninvasively characterizing in vivo fluid-mechanical energy losses and to apply it in a pilot study of patients known to express abnormal Aortic Flow patterns.

    Methods

    Four-dimensional Flow MRI was used to characterize laminar viscous energy losses in the aorta of normal controls (n = 12, age = 37 ± 10 yr), patients with Aortic dilation (n = 16, age = 52 ± 8 yr), and patients with Aortic valve stenosis matched for age and Aortic size (n = 14, age = 46 ± 15 yr), using a relationship between the three-dimensional velocity field and viscous energy dissipation.

    Results

    Viscous energy loss was elevated significantly in the thoracic aorta in patients with dilated aorta (3.6 ± 1.3 mW, P = 0.024) and patients with Aortic stenosis (14.3 ± 8.2 mW, P < 0.001) compared with healthy volunteers (2.3 ± 0.9 mW). The same pattern of significant differences was seen in the ascending aorta, where viscous energy losses in patients with dilated aortas (2.2 ± 1.1 mW, P = 0.021) and patients with Aortic stenosis (10.9 ± 6.8 mW, P < 0.001) were elevated compared with healthy volunteers (1.2 ± 0.6 mW). Conclusion This technique provides a capability to quantify the contribution of abnormal laminar blood Flow to increased ventricular afterload. In this pilot study, viscous energy loss in patient cohorts was significantly elevated and indicates that cardiac afterload is increased due to abnormal Flow. Magn Reson Med 72:620–628, 2014. © 2013 Wiley Periodicals, Inc.