scholarly journals Improved Efficiency of Intraventricular Blood Flow Transit Under Cardiac Stress: A 4D Flow Dobutamine CMR Study

2020 ◽  
Vol 7 ◽  
Author(s):  
Jonathan Sundin ◽  
Jan Engvall ◽  
Eva Nylander ◽  
Tino Ebbers ◽  
Ann F. Bolger ◽  
...  
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Human Heart ◽  
Flow Patterns ◽  
Relative Increase ◽  
Dobutamine Infusion ◽  
Residual Volume ◽  
4D Flow ◽  
Lv Dysfunction ◽  
Flow Components

Introduction: The effects of heart rate, inotropy, and lusitropy on multidimensional flow patterns and energetics within the human heart remain undefined. Recently, reduced volume and end-diastolic kinetic energy (KE) of the portion of left ventricular (LV) inflow passing directly to outflow, Direct flow (DF), have been shown to reflect inefficient LV pumping and to be a marker of LV dysfunction in heart failure patients. In this study, we hypothesized that increasing heart rate, inotropy, and lusitropy would result in an increased efficiency of intraventricular blood flow transit. Therefore, we sought to investigate LV 4D blood flow patterns and energetics with dobutamine infusion.Methods: 4D flow and morphological cardiovascular magnetic resonance (CMR) data were acquired in twelve healthy subjects: at rest and with dobutamine infusion to achieve a target heart rate ~60% higher than the resting heart rate. A previously validated method was used for flow analysis: pathlines were emitted from the end-diastolic (ED) LV blood volume and traced forward and backward in time to separate four functional LV flow components. For each flow component, KE/mL blood volume at ED was calculated.Results: With dobutamine infusion there was an increase in heart rate (64%, p < 0.001), systolic blood pressure (p = 0.02) and stroke volume (p = 0.01). Of the 4D flow parameters, the most efficient flow component (DF), increased its proportion of EDV (p < 0.001). The EDV proportion of Residual volume, the blood residing in the ventricle over at least two cardiac cycles, decreased (p < 0.001). The KE/mL at ED for all flow components increased (p < 0.001). DF had the largest absolute and relative increase while Residual volume had the smallest absolute and relative increase.Conclusions: This study demonstrates that it is feasible to compare 4D flow patterns within the normal human heart at rest and with stress. At higher heart rate, inotropy and lusitropy, elicited by dobutamine infusion, the efficiency of intraventricular blood flow transit improves, as quantified by an increased relative volume and pre-systolic KE of the most efficient DF component of the LV volume. The change in these markers may allow a novel assessment of LV function and LV dysfunction over a range of stress.

Abstract 13435: Deranged Intra-Cardiac Blood Flow Components and Kinetic Energy in Dilated Cardiomyopathy Are an Additional Marker of Disease Severity and Correlate With Established Markers of Prognosis

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Victoria Stoll ◽  
Aaron Hess ◽  
Eylem Levelt ◽  
Jonatan Eriksson ◽  
Petter Dyverfeldt ◽  
...  
Keyword(s):  
Blood Flow ◽  
Kinetic Energy ◽  
Dilated Cardiomyopathy ◽  
Disease Severity ◽  
Myocardial Strain ◽  
Flow Patterns ◽  
Left Ventricular ◽  
4D Flow ◽  
Flow Components ◽  
Functional Components

Introduction: Heart failure (HF) due to dilated cardiomyopathy (DCM) is a complex syndrome in which numerous cellular, mechanical and flow processes/interactions become deranged. Insights into derangement of left ventricular intra-cardiac flow patterns and kinetic energy (KE) are now afforded by the use of 4D flow CMR. Previous studies have found derangements of intra-ventricular flow components and KE within DCM patients compared to healthy volunteers. Hypothesis: We hypothesised that increasing derangement in 4D flow measures would relate to: 1) decreased mechanical cardiac function, as assessed by myocardial strain, 2) increased levels of biochemical remodelling markers and 3) worsening patient symptoms and functional capacity. Methods: 26 idiopathic DCM patients (69% male, mean age 55±2 yr, LVEF 35±2%) and 10 controls (70% male, mean age 57±4yr, LVEF 68±1.2%) were assessed with 3T CMR. Results: The LV volume was divided into 4 functional components; direct flow (DF), delayed ejection flow (DEF), retained inflow (RI) and residual volume (RV). Compared to controls DCM’s had significantly decreased DF (11±1% vs 38±2%) and increased RV (51±2% vs 31±1%) (fig a). The KE at end diastole differed significantly for all flow components between groups (fig b). Circumferential strain was significantly impaired in DCM’s vs controls (-9.9±0.8% vs -19.7±0.5%, p<0.0001). DF KE correlated positively to the 6 minute walk test (6MWT) and strain, and negatively to the Minnesota HF questionnaire and BNP (fig c). Conclusions: DCM patients demonstrated less efficient blood flow patterns and deranged KE profiles. The greater the derangement of flow parameters from normal, the worse the myocardial strain, BNP, 6MWT and patient symptoms. This study suggests that flow parameter derangements are novel biomarkers of disease severity in DCM, correlating with established markers of prognosis such as BNP and 6MWT and may become useful in monitoring novel therapies and predicting prognosis.

Blood Flow Patterns In The Ascending Aorta after TAVI And Surgical Aortic Valve Replacement: A Study Using 4D Flow MRI

2014 ◽  
Author(s):  
Ralf Felix Trauzeddel ◽  
Ulrike Löbe ◽  
Alex Barker ◽  
Carmen Gelsinger ◽  
Christian Butter ◽  
...  
Keyword(s):  
Blood Flow ◽  
Aortic Valve ◽  
Flow Patterns ◽  
Ascending Aorta ◽  
Shear Stresses ◽  
Healthy Controls ◽  
4D Flow Mri ◽  
4D Flow ◽  
Flow Mri ◽  
Blood Flow Patterns

Background Transcatheter aortic valve implantation (TAVI) is a new method for treating patients with severe aortic stenosis with high risk for or rejected from conventional heart surgery. Its impact on blood flow patterns and parameters in the ascending aorta are unknown. Using 4-dimensional phase contrast MRI (4D Flow MRI) we examined the hemodynamics in the ascending aorta after TAVI and compared them to stented bioprostheses and healthy controls. Methods We used 4D Flow MRI (spatial resolution 1.8x1.8x2.5mm3; temporal resolution 13-22 phases/heart cycle) of the ascending aorta in 14 patients with TAVI (mean age 76 years, 8 males, all Edwards Sapien), 12 patients with different stented bioprostheses (mean age 77 years, 8 males) and 9 healthy controls (mean age 55 years, 8 males) controls using a 1.5T MR system. We examined the distribution of the maximum systolic wall shear stresses as well as the maximum blood flow velocities in the mid-ascending aorta. Results Patients with TAVI and stented bioprosthesis revealed an asymetric distribution of the wall shear stresses with significantly elevated values at the anterior and right-anterior curvature and significantly lower values at the posterior curvature compared to the healthy controls. Concerning the maximum velocities both TAVI and stented bioprostheses revealed an asymetric distribution along the right-anterior curvature where TAVI showed a more anterior distribution compared to the healty controls which showed a central distribution. Conclusion The blood flow patterns in patients with TAVI and stented bioprostheses differs significantly from the ones in healthy controls. However, TAVI and stented bioprosthesis showed small but significant regional differences.

Influence of heart rate and vasoactive drugs on blood flow patterns at the canine ilio-femoral bifurcation

1994 ◽  
Vol 28 (11) ◽  
pp. 1686-1693 ◽  
Author(s):  
C. J H Jones ◽  
M J. Lever ◽  
K. H Parker ◽  
Y. Ogasawara ◽  
O. Hiramatsu ◽  
...  
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Flow Patterns ◽  
Vasoactive Drugs ◽  
Blood Flow Patterns

Abstract 12827: Alterations in Flow Patterns and Wall Shear Stress in Pulmonary Artery Visualized With Phase-resolved 3D Cine Phase Contrast MRI (4D-Flow) in Patients With Systemic Sclerosis

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Kenichiro Suwa ◽  
Tomoaki Sakakibara ◽  
Takeji Saitoh ◽  
Yutaro Kaneko ◽  
Makoto Sano ◽  
...  
Keyword(s):  
Blood Flow ◽  
Shear Stress ◽  
Systemic Sclerosis ◽  
Wall Shear Stress ◽  
Flow Velocity ◽  
Flow Patterns ◽  
Helical Flow ◽  
4D Flow ◽  
Control Subjects ◽  
Diastolic Phase

Background: The pulmonary circulation is impaired in patients with systemic sclerosis (SSc), and the analysis of pulmonary arterial (PA) blood flow has a great clinical significance. Using 4D-Flow, we studied the changes in PA blood flow velocity vectors and wall shear stress (WSS) in SSc patients. Methods: Twenty one SSc patients (M/F: 1/20, 56±15 years) including 2 PA hypertension, and 7 control subjects underwent 4D-Flow. We set planes traversing the main and first branches of PA, and the velocity vectors were post-processed to delineate streamline images. WSS images were obtained at the surface of PA. The plane-averaged flow velocity at the main PA, surface-averaged WSS, and oscillatory shear index (OSI), the %WSS acting in other directions from the mean WSS vector during a cardiac cycle, were compared. Results: (1) The PA flow showed laminar flow pattern at the early systolic phase in all patients and subjects, but diffuse helical flow in 11 SSc patients (right upper), focal helical flow in 6 SSc patients and 2 control subjects at the late systolic to early diastolic phase. The other 4 SSc patients and 5 control subjects had continuous laminal flow (left upper). (2) The peak systolic PA flow velocity did not differ between them, whereas the diastolic flow velocity was significantly greater in SSc patients (minimum velocity; 26±24 mm/sec vs. -26±52 mm/sec, p<0.01). (3) WSS at the peak systolic flow velocity was significantly lower and spatially heterogeneous in SSc patients (lower figs; 1.1±0.2 Pa vs. 1.4±0.4 Pa, p<0.01). Both WSS at the diastolic phase and OSI were significantly greater in SSc patients (minimum WSS; 0.28±0.07 Pa vs. 0.19±0.04 Pa, p<0.01, OSI; 0.14±0.03% vs. 0.09±0.02%, p<0.05). Conclusions: The 4D-Flow disclosed the different PA flow patterns between SSc patients and control subjects. In SSc patients, WSS at the PA was generally decreased and varied spatially and temporally. 4D-Flow has a potential to detect the subclinical changes of PA flow dynamics in SSc.

scholarly journals Development of a New Approach for the Assessment of Complex Blood Flow Patterns in the Left Atrium From 4D Flow MRI

2018 ◽  
Author(s):  
Enrico Soldati ◽  
Thomas Dietenbeck ◽  
Alban Redheuil ◽  
Alessandro Masci ◽  
Sophia Houriez ◽  
...  
Keyword(s):  
Blood Flow ◽  
Left Atrium ◽  
Flow Patterns ◽  
4D Flow Mri ◽  
4D Flow ◽  
New Approach ◽  
Flow Mri ◽  
Blood Flow Patterns

Abstract 17363: Cardiac Output and Valve Orientation Affect Blood Flow Patterns Local to Bioprosthetic Pulmonary Valves in Tetralogy of Fallot

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Nicole Schiavone ◽  
Christopher Elkins ◽  
Doff B McElhinney ◽  
John K Eaton ◽  
Alison L Marsden
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Tetralogy Of Fallot ◽  
Flow Patterns ◽  
Velocity Fields ◽  
4D Flow Mri ◽  
4D Flow ◽  
Flow Mri ◽  
Leaflet Motion ◽  
Blood Flow Patterns

Introduction: Tetralogy of Fallot (ToF) typically requires surgical repair of the right ventricular outflow tract (RVOT) and subsequent placement of an artificial pulmonary valve. Bioprosthetic valve longevity is highly variable and there is currently little understanding of what hemodynamic factors may lead to early valve dysfunction. Hypothesis: We hypothesize that cardiac output and valve orientation impact the performance of bioprosthetic valves by affecting blood flow patterns in the RVOT. Methods: We analyzed hemodynamics in a 3D printed ToF anatomy model in a physiological flow loop. A 25mm surgical valve was implanted in the model at two orientations: native and rotated 180 degrees. Full 3D, three-component, phase-averaged velocity fields were obtained over the cardiac cycle using 4D flow MRI at cardiac outputs of 2, 3.5, and 5 L/min. We acquired images of valve leaflet motion at 1500Hz. The 4D flow MRI and high-speed camera experiments were run identically, allowing us to examine the relationship between flow fields and leaflet motion. Results: The full velocity fields from the MRI scans revealed key differences among cases in flow features including location of reverse flow regions, systolic jet shape, and asymmetry local to the valve. At 2 L/min, the forward flow through the jet was more asymmetric compared to the other cases and a strong vortex formed, indicating a region of recirculation. With the rotated valve orientation, the 2 L/min case also produced a unique pattern as flow was washed from the RVOT inner curve back toward the center of the valve (Fig 1). Leaflet behavior during systole varied with cardiac output as well, as higher frequency flutter was observed at 5 L/min and the effective valve orifice area was decreased by 8.5% at 2 L/min compared to 5 L/min. Conclusions: We observed key differences in flow patterns and leaflet motion due to cardiac output and valve orientation that could impact leaflet loading and fatigue and long-term valve function.

Three-dimensional and four-dimensional flow assessment in congenital heart disease

Heart ◽  
2019 ◽  
Vol 106 (6) ◽  
pp. 421-426 ◽  
Author(s):  
Evangeline Warmerdam ◽  
Gregor J Krings ◽  
Tim Leiner ◽  
Heynric B Grotenhuis
Keyword(s):  
Congenital Heart Disease ◽  
Blood Flow ◽  
Heart Disease ◽  
Vascular Function ◽  
Congenital Heart ◽  
Surgical Techniques ◽  
Flow Patterns ◽  
Congenital Defects ◽  
4D Flow ◽  
Blood Flow Patterns

Congenital heart disease (CHD) is the most common form of congenital defects, with an incidence of 8 per 1000 births. Due to major advances in diagnostics, perioperative care and surgical techniques, the survival rate of patients with CHD has improved dramatically. Conversely, although 70%–95% of infants with CHD survive into adulthood, the rate of long-term morbidity, which often requires (repeat) intervention, has increased. Recently, the role of altered haemodynamics in cardiac development and CHD has become a subject of interest. Patients with CHD often have abnormal blood flow patterns, either due to the primary cardiac defect or as a consequence of the surgical intervention(s). Research suggests that these abnormal blood flow patterns may contribute to diminished cardiac and vascular function. Serial assessment of haemodynamic parameters in patients with CHD may allow for improved understanding of the often complex haemodynamics in these patients and thereby potentially guide the timing and nature of interventions with the aim of preventing progression of cardiovascular deterioration. In this article we will discuss two novel non-invasive four-dimensional (4D) techniques to evaluate cardiovascular haemodynamics: 4D-flow cardiac magnetic resonance and computational fluid dynamics. This review focuses on the additional value of these two modalities in the evaluation of patients with CHD with abnormal flow patterns, who could benefit from advanced haemodynamic evaluation: patients with coarctation of the aorta, bicuspid aortic valve, tetralogy of Fallot and patients after Fontan palliation.

scholarly journals 4D flow magnetic resonance imaging to assess left atrial haemodynamics in healthy and hypertrophic subjects

2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
X Morales Ferez ◽  
J Mill ◽  
G Delso ◽  
M Sitges ◽  
A Doltra ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Flow ◽  
Spectral Analysis ◽  
Magnetic Resonance ◽  
Healthy Subjects ◽  
Ventricular Dysfunction ◽  
Flow Patterns ◽  
Resonance Imaging ◽  
4D Flow ◽  
Blood Flow Patterns

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): - University, research centre and hospital foundation grants for the contracting of new research staff (FI 2020) - Spanish Ministry of Economy and Competitiveness Retos investigacion project Introduction The assessment of the left atrium (LA) haemodynamics is key to better understand the development of LA-related pathological processes. In this regard 4D flow magnetic resonance imaging (MRI) can provide complementary information to standard Doppler echocardiographic studies and identify complex blood flow patterns. Yet, until recently, the left atrium (LA) has been largely left aside in 4D flow MRI studies. Purpose We aimed at assessing the LA haemodynamics of healthy and hypertrophic cardiomyopathy (HCM) subjects with a qualitative visualization of flow patterns and deriving quantitative indices related to ventricular dysfunction from pulmonary veins (PV)  and mitral valve (MV) velocity profiles. Methods Segmentation was performed directly over 4D flow angiograms. A total of 20 cases were processed, 11 healthy and 9 HCM subjects. 4D velocity matrices were masked with the segmented mask to isolate LA haemodynamics. Velocity profiles were then obtained in the PV and MV and integrated over planes perpendicular to the lumen of the vessels to create velocity spectrograms. Fourier spectral analysis was applied to the velocity curves to highlight differences that might go unnoticed in the time domain. In addition, the Q-Criterion was computed for vortex identification, visually inspecting both cohorts across the whole cardiac cycle. Results Fourier spectral analysis of the velocity curves suggested that overall, healthy patients have higher dynamic range of the velocity curves. It can be observed in Figure 1, that the usual E/A MV velocity pattern is preserved in 10 of the 11 healthy subjects while 5 of the HCM patients present significant alterations of said curve. In fact, patients 4, 6, 7 and 8 seem to present a 3 peaked MV velocity curve. The vortex analysis identified 3 main types of vortices in healthy subjects: a ‘filling’ systolic vortex (10/11) arising near the most dominant PV (usually the left superior PV) as seen in Figure 2; a conduit phase vortex (7/11), similar in nature to the preceding systolic vortex; and an E-wave vortex (9/11) attached to the LA ostium. Four of the HCM patients (out of the five with altered MV velocity profile) also showed a systolic vortex, but with more complex blood flow patterns and emerging far from the PVs. One of such vortices is shown in Figure 2, composed of two distinct eddies near the MV. The E-wave vortex was also observed but was less predominant than in healthy subjects (3/9). Conclusions 4D Flow analysis of the LA is feasible and might hold promise in the understanding of the complex haemodynamics in ventricular dysfunction. Abstract Figure. Velocity Spectrograms and Vortices

scholarly journals Ventricular flow analysis and its association with exertional capacity in repaired tetralogy of Fallot: 4D flow cardiovascular magnetic resonance study

2022 ◽  
Vol 24 (1) ◽  
Author(s):  
Xiaodan Zhao ◽  
Liwei Hu ◽  
Shuang Leng ◽  
Ru-San Tan ◽  
Ping Chai ◽  
...  
Keyword(s):  
Cardiovascular Magnetic Resonance ◽  
Healthy Controls ◽  
Residual Volume ◽  
4D Flow ◽  
Direct Flow ◽  
Age And Gender ◽  
4D Flow Cmr ◽  
Flow Parameters ◽  
Flow Components ◽  
And Gender

Abstract Background Four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) allows quantification of biventricular blood flow by flow components and kinetic energy (KE) analyses. However, it remains unclear whether 4D flow parameters can predict cardiopulmonary exercise testing (CPET) as a clinical outcome in repaired tetralogy of Fallot (rTOF). Current study aimed to (1) compare 4D flow CMR parameters in rTOF with age- and gender-matched healthy controls, (2) investigate associations of 4D flow parameters with functional and volumetric right ventricular (RV) remodelling markers, and CPET outcome. Methods Sixty-three rTOF patients (14 paediatric, 49 adult; 30 ± 15 years; 29 M) and 63 age- and gender-matched healthy controls (14 paediatric, 49 adult; 31 ± 15 years) were prospectively recruited at four centers. All underwent cine and 4D flow CMR, and all adults performed standardized CPET same day or within one week of CMR. RV remodelling index was calculated as the ratio of RV to left ventricular (LV) end-diastolic volumes. Four flow components were analyzed: direct flow, retained inflow, delayed ejection flow and residual volume. Additionally, three phasic KE parameters normalized to end-diastolic volume (KEiEDV), were analyzed for both LV and RV: peak systolic, average systolic and peak E-wave. Results In comparisons of rTOF vs. healthy controls, median LV retained inflow (18% vs. 16%, P = 0.005) and median peak E-wave KEiEDV (34.9 µJ/ml vs. 29.2 µJ/ml, P = 0.006) were higher in rTOF; median RV direct flow was lower in rTOF (25% vs. 35%, P < 0.001); median RV delayed ejection flow (21% vs. 17%, P < 0.001) and residual volume (39% vs. 31%, P < 0.001) were both greater in rTOF. RV KEiEDV parameters were all higher in rTOF than healthy controls (all P < 0.001). On multivariate analysis, RV direct flow was an independent predictor of RV function and CPET outcome. RV direct flow and RV peak E-wave KEiEDV were independent predictors of RV remodelling index. Conclusions In this multi-scanner multicenter 4D flow CMR study, reduced RV direct flow was independently associated with RV dysfunction, remodelling and, to a lesser extent, exercise intolerance in rTOF patients. This supports its utility as an imaging parameter for monitoring disease progression and therapeutic response in rTOF. Clinical Trial Registrationhttps://www.clinicaltrials.gov. Unique identifier: NCT03217240.

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