The kinetic energies of left ventricular 4D flow components correlate with established markers of prognosis and represent novel imaging biomarkers in both ischaemic and dilated cardiomyopathy

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.

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Impact of age, sex and ethnicity on intra-cardiac flow components and left ventricular kinetic energy derived from 4D flow CMR

International Journal of Cardiology ◽

10.1016/j.ijcard.2021.05.035 ◽

2021 ◽

Author(s):

Xiaodan Zhao ◽

Ru-San Tan ◽

Pankaj Garg ◽

Ping Chai ◽

Shuang Leng ◽

...

Keyword(s):

Kinetic Energy ◽

Left Ventricular ◽

4D Flow ◽

4D Flow Cmr ◽

Flow Components

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Comprehensive Assessment of Left Intraventricular Hemodynamics Using a Finite Element Method: An Application to Dilated Cardiomyopathy Patients

Applied Sciences ◽

10.3390/app112311165 ◽

2021 ◽

Vol 11 (23) ◽

pp. 11165

Author(s):

Pamela Franco ◽

Julio Sotelo ◽

Cristian Montalba ◽

Bram Ruijsink ◽

Eric Kerfoot ◽

...

Keyword(s):

Finite Element ◽

Dilated Cardiomyopathy ◽

Sensitivity Study ◽

Left Ventricular ◽

Local Analysis ◽

Hemodynamic Parameters ◽

4D Flow ◽

Dissipation Energy ◽

Element Approach ◽

Flow Mri

In this paper, we applied a method for quantifying several left intraventricular hemodynamic parameters from 4D Flow data and its application in a proof-of-concept study in dilated cardiomyopathy (DCM) patients. In total, 12 healthy volunteers and 13 DCM patients under treatment underwent short-axis cine b-SSFP and 4D Flow MRI. Following 3D segmentation of the left ventricular (LV) cavity and registration of both sequences, several hemodynamic parameters were calculated at peak systole, e-wave, and end-diastole using a finite element approach. Sensitivity, inter- and intra-observer reproducibility of hemodynamic parameters were evaluated by analyzing LV segmentation. A local analysis was performed by dividing the LV cavity into 16 regions. We found significant differences between volunteers and patients in velocity, vorticity, viscous dissipation, energy loss, and kinetic energy at peak systole and e-wave. Furthermore, although five patients showed a recovered ejection fraction after treatment, their hemodynamic parameters remained low. We obtained several hemodynamic parameters with high inter- and intra-observer reproducibility. The sensitivity study revealed that hemodynamic parameters showed a higher accuracy when the segmentation underestimates the LV volumes. Our approach was able to identify abnormal flow patterns in DCM patients compared to volunteers and can be applied to any other cardiovascular diseases.

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Left ventricular four-dimensional blood flow energetics and vorticity in chronic myocardial infarction patients with/without left ventricular thrombus

European Heart Journal - Cardiovascular Imaging ◽

10.1093/ehjci/jeab090.091 ◽

2021 ◽

Vol 22 (Supplement_2) ◽

Author(s):

A Demirkiran ◽

M ECJ Hassell ◽

P Garg ◽

M SM Elbaz ◽

R Delewi ◽

...

Keyword(s):

Myocardial Infarction ◽

Vortex Ring ◽

Left Ventricular ◽

Residual Flow ◽

4D Flow ◽

Direct Flow ◽

4D Flow Cmr ◽

Ventricular Thrombus ◽

The Mean ◽

Flow Components

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): The British Heart Foundation [FS/10/62/28409] and Dutch ZonMw [104003001]. Background Left ventricular thrombus (LVT) formation is a frequent and serious complication of myocardial infarction (MI). How global LV flow characteristics are related to this phenomenon is yet uncertain. In this study, we investigated LV flow differences using 4D flow cardiovascular magnetic resonance (CMR) between chronic MI patients with LVT [MI-LVT(+)] and without LVT [MI-LVT(-)], and healthy controls. Methods In this prospective cohort study, the 4D flow CMR data were acquired in 19 chronic MI patients (MI-LVT(+), n= 9 and MI-LVT(-), n= 10) and 9 age-matched controls. All included subjects were in sinus rhythm. The following LV flow parameters were obtained: LV flow components (direct, retained, delayed, residual), mean and peak KE values (indexed to instantaneous LV volume), mean and peak vorticity values, and diastolic vortex ring properties (position, orientation, shape). Results The MI patients demonstrated a significantly larger amount of delayed and residual flow, and a smaller amount of direct flow compared to controls (p = 0.02, p = 0.03, and p < 0.001, respectively). The MI-LVT(+) patients demonstrated numerically increased residual flow and reduced retained and direct flow in comparison to MI-LVT(-) patients. Systolic mean and peak LV blood flow KE values were significantly lower in MI patients compared to controls (p = 0.04, p = 0.03, respectively). Overall, the mean and peak LV vorticity values were significantly lower in MI patients compared to controls. The mean vorticity at the basal level was significantly higher in MI-LVT(+) than in MI-LVT(-) patients (p < 0.01). The vortex ring core during E-wave in MI-LVT(-) group was located closer to the mitral annulus and in a less tilted orientation to the LV compared to MI-LVT(+) group (p = 0.05, p < 0.01, respectively). Conclusion Chronic MI patients with LVT express a different distribution of LV flow components, irregular vorticity vector fields, and altered diastolic vortex ring geometric properties as assessed by 4D flow CMR. Larger prospective studies are warranted to further evaluate these initial observations.

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