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- Postigo, Andrea, et al.
(författare)
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Assessment Of Blood Flow Transport In The Left Ventricle Using Ultrasound. Validation Against 4-D Flow Cardiac Magnetic Resonance
- 2022
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Ingår i: Ultrasound in Medicine and Biology. - : Elsevier Science Inc. - 0301-5629 .- 1879-291X. ; 48:9, s. 1822-1832
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Tidskriftsartikel (refereegranskat)abstract
- Four-dimensional flow cardiac magnetic resonance (CMR) is the reference technique for analyzing blood transport in the left ventricle (LV), but similar information can be obtained from ultrasound. We aimed to validate ultrasound-derived transport in a head-to-head comparison against 4D flow CMR. In five patients and two healthy volunteers, we obtained 2D + t and 3D + t (4D) flow fields in the LV using transthoracic echocardiog-raphy and CMR, respectively. We compartmentalized intraventricular blood flow into four fractions of end -dia-stolic volume: direct flow (DF), retained inflow (RI), delayed ejection flow (DEF) and residual volume (RV). Using ultrasound we also computed the properties of LV filling waves (percentage of LV penetration and percent-age of LV volume carried by E/A waves) to determine their relationships with CMR transport. Agreement between both techniques for quantifying transport fractions was good for DF and RV (Ric [95% confidence inter-val]: 0.82 [0.33, 0.97] and 0.85 [0.41, 0.97], respectively) and moderate for RI and DEF (Ric= 0.47 [-0.29, 0.88] and 0.55 [-0.20, 0.90], respectively). Agreement between techniques to measure kinetic energy was variable. The amount of blood carried by the E-wave correlated with DF and RV (R = 0.75 and R = 0.63, respectively). There-fore, ultrasound is a suitable method for expanding the analysis of intraventricular flow transport in the clinical setting. (E-mail: javier.bermejo@salud.madrid.org) (c) 2022 The Author(s). Published by Elsevier Inc. on behalf of World Federation for Ultrasound in Medicine & Biology.
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| 2. |
- Rossini, Lorenzo, et al.
(författare)
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Intraventricular Flow Patterns in Patients Treated with Left Ventricular Assist Devices
- 2021
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Ingår i: ASAIO Journal. - 1538-943X. ; 67:1, s. 74-83
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Tidskriftsartikel (refereegranskat)abstract
- The success of left ventricular assist device (LVAD) therapy is hampered by complications such as thrombosis and bleeding. Understanding blood flow interactions between the heart and the LVAD might help optimize treatment and decrease complication rates. We hypothesized that LVADs modify shear stresses and blood transit in the left ventricle (LV) by changing flow patterns and that these changes can be characterized using 2D echo color Doppler velocimetry (echo-CDV). We used echo-CDV and custom postprocessing methods to map blood flow inside the LV in patients with ongoing LVAD support (Heartmate II, N = 7). We compared it to healthy controls (N = 20) and patients with dilated cardiomyopathy (DCM, N = 20). We also analyzed intraventricular flow changes during LVAD ramp tests (baseline ± 400 rpm). LVAD support reversed the increase in blood stasis associated with DCM, but it did not reduce intraventricular shear exposure. Within the narrow range studied, the ventricular flow was mostly insensitive to changes in pump speed. Patients with significant aortic insufficiency showed abnormalities in blood stasis and shear indices. Overall, this study suggests that noninvasive flow imaging could potentially be used in combination with standard clinical methods for adjusting LVAD settings to optimize flow transport and minimize stasis on an individual basis.
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