Abstract 14367: Abnormal Pulmonary Flow is Associated With Impaired Right Ventricular Coupling in Patients With COPD

Introduction: Cor Pulmonale or right ventricular (RV) dysfunction due to pulmonary disease is an expected complication of COPD resulting from increased afterload mediated by hypoxic pulmonary vasoconstriction as well as the destruction of the pulmonary vascular bed. Early detection of elevated RV afterload has been previously demonstrated by visualization of abnormal flow patterns in the proximal pulmonary arteries. Prior quantitative analysis of helicity in the pulmonary arteries of pulmonary hypertension patients has demonstrated a strong association between helicity and increased RV afterload. Hypothesis: Patients with COPD will have abnormal pulmonary flow as evaluated by 4D-Flow MRI and associated with RV function and pulmonary arterial stiffness. Methods: Patients with COPD (n=15) (65yrs ± 6) and controls (n=10) (58yrs ± 9) underwent 4D-Flow MRI to calculate helicity (Figure 1A). The helicity was calculated in 2 segments: 1) the main pulmonary artery (MPA) and 2) along the RV outflow tract (RVOT) - MPA axis. Main pulmonary arterial stiffness was measured using the relative area change (RAC). Results: COPD patients had decreased helicity relative to healthy controls in the MPA (19.4±7.8 vs 32.8±15.9 s -2 , P=0.007) (Figure 1B). Additionally, COPD patients had reduced helicity along the RVOT-MPA axis (33.2±9.0 vs 43.5±8.3 s -2 , P=0.010). The helicity measured in the MPA was associated with RV end-systolic volume (R=0.59, P = 0.002), RVEF (R=0.631, P<0.001), RAC (R=-0.61, P=0.001). e combined helicity along the MPA-RVOT axis was associated with RVEF (R=0.74, P<0.001), RVESV (R=-0.57, P=0.004), and RAC (R=0.42, P=0.005). Conclusion: Patients with COPD show quantitatively abnormal flow hemodynamics, when compared with healthy controls, as assessed by 4D-Flow MRI. A strong association between helicity along the MPA-RV outflow tract axis and RV function suggests that 4D-Flow MRI might be a sensitive tool in evaluating RV - pulmonary arterial coupling in COPD.

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Pulmonary Arteriovenous Pressure Gradient and Time-Averaged Mean Velocity of Small Pulmonary Arteries Can Serve as Sensitive Biomarkers in the Diagnosis of Pulmonary Arterial Hypertension: A Preclinical Study by 4D-Flow MRI

Diagnostics ◽

10.3390/diagnostics12010058 ◽

2021 ◽

Vol 12 (1) ◽

pp. 58

Author(s):

Ali Nahardani ◽

Simon Leistikow ◽

Katja Grün ◽

Martin Krämer ◽

Karl-Heinz Herrmann ◽

...

Keyword(s):

Pulmonary Arterial Hypertension ◽

Arterial Hypertension ◽

Pressure Gradient ◽

Pulmonary Arteries ◽

Preclinical Study ◽

4D Flow Mri ◽

4D Flow ◽

Mean Velocity ◽

Flow Mri ◽

Pulmonary Arterial

(1) Background: Pulmonary arterial hypertension (PAH) is a serious condition that is associated with many cardiopulmonary diseases. Invasive right heart catheterization (RHC) is currently the only method for the definitive diagnosis and follow-up of PAH. In this study, we sought a non-invasive hemodynamic biomarker for the diagnosis of PAH. (2) Methods: We applied prospectively respiratory and cardiac gated 4D-flow MRI at a 9.4T preclinical scanner on three different groups of Sprague Dawley rats: baseline (n = 11), moderate PAH (n = 8), and severe PAH (n = 8). The pressure gradients as well as the velocity values were analyzed from 4D-flow data and correlated with lung histology. (3) Results: The pressure gradient between the pulmonary artery and vein on the unilateral side as well as the time-averaged mean velocity values of the small pulmonary arteries were capable of distinguishing not only between baseline and severe PAH, but also between the moderate and severe stages of the disease. (4) Conclusions: The current preclinical study suggests the pulmonary arteriovenous pressure gradient and the time-averaged mean velocity as potential biomarkers to diagnose PAH.

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Circulation derived from 4D flow MRI correlates with right ventricular dysfunction in patients with tetralogy of Fallot

Scientific Reports ◽

10.1038/s41598-021-91125-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Nanae Tsuchiya ◽

Michinobu Nagao ◽

Yumi Shiina ◽

Shohei Miyazaki ◽

Kei Inai ◽

...

Keyword(s):

Right Ventricular ◽

Tetralogy Of Fallot ◽

Main Pulmonary Artery ◽

Vortex Formation ◽

Cine Mri ◽

Short Axis ◽

4D Flow Mri ◽

4D Flow ◽

Flow Mri ◽

Rv Function

AbstractWe used 4D-flow MRI to investigate circulation, an area integral of vorticity, in the main pulmonary artery (MPA) as a new hemodynamic parameter for assessing patients with a repaired Tetralogy of Fallot (TOF). We evaluated the relationship between circulation, right ventricular (RV) function and the pulmonary regurgitant fraction (PRF). Twenty patients with a repaired TOF underwent cardiac MRI. Flow-sensitive 3D-gradient sequences were used to obtain 4D-flow images. Vortex formation in the MPA was visualized, with short-axis and longitudinal vorticities calculated by software specialized for 4D flow. The RV indexed end-diastolic/end-systolic volumes (RVEDVi/RVESVi) and RV ejection fraction (RVEF) were measured by cine MRI. The PR fraction (PRF) and MPA area were measured by 2D phase-contrast MRI. Spearman ρ values were determined to assess the relationships between circulation, RV function, and PRF. Vortex formation in the MPA occurred in 15 of 20 patients (75%). The longitudinal circulation (11.7 ± 5.1 m2/s) was correlated with the RVEF (ρ = − 0.85, p = 0.0002), RVEDVi (ρ = 0.62, p = 0.03), and RVESVi (ρ = 0.76, p = 0.003) after adjusting for the MPA size. The short-axis circulation (9.4 ± 3.4 m2/s) in the proximal MPA was positively correlated with the MPA area (ρ = 0.61, p = 0.004). The relationships between the PRF and circulation or RV function were not significant. Increased longitudinal circulation in the MPA, as demonstrated by circulation analysis using 4D flow MRI, was related to RV dysfunction in patients with a repaired TOF.

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Sildenafil Administration Improves Right Ventricular Function on 4D Flow MRI in Young Adults Born Premature

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00824.2020 ◽

2021 ◽

Author(s):

Philip A Corrado ◽

Gregory P Barton ◽

Christopher J François ◽

Oliver Wieben ◽

Kara N Goss

Keyword(s):

Heart Rate ◽

Young Adults ◽

Kinetic Energy ◽

Right Ventricular ◽

Right Atrial ◽

4D Flow Mri ◽

4D Flow ◽

Direct Flow ◽

Flow Mri ◽

Rv Function

Background: Extreme preterm birth conveys an elevated risk of heart failure by young adulthood. Smaller biventricular chamber size, diastolic dysfunction, and pulmonary hypertension may contribute to reduced ventricular-vascular coupling. However, how hemodynamic manipulations may affect right ventricular (RV) function and coupling remains unknown. Methods: As a pilot study, 4D flow MRI was used to assess the effect of afterload reduction and heart rate reduction on cardiac hemodynamics and function. Young adults born premature were administered sildenafil (a pulmonary vasodilator) and metoprolol (a beta blocker) on separate days, and MRI with 4D flow completed before and after each drug administration. Endpoints include cardiac index (CI), direct flow fractions, and ventricular kinetic energy including E/A wave kinetic energy ratio. Results: Sildenafil resulted in a median CI increase of 0.24 L/min/m2 (P=0.02), mediated through both an increase in heart rate (HR) and stroke volume. Although RV ejection fraction improved only modestly, there was a significant increase (4% of end diastolic volume) in RV direct flow fraction (P=0.04), consistent with hemodynamic improvement. Metoprolol administration resulted in a 5-bpm median decrease in HR (P=0.01), a 0.37 L/min/m2 median decrease in CI (P=0.04), and a reduction in time-averaged kinetic energy (KE) in both ventricles (P<0.01), despite increased RV diastolic E/A KE ratio (P=0.04). Conclusions: Despite reduced right atrial workload, metoprolol significantly depressed overall cardiac systolic function. Sildenafil, however, increased CI and improved RV function, as quantified by the direct flow fraction. The preterm heart appears dependent on HR, but sensitive to RV afterload manipulations.

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

10.14293/p2199-8442.1.sop-med.p0low9.v1 ◽

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.

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4D flow MRI versus conventional 2D for measuring pulmonary flow after Tetralogy of Fallot repair

International Journal of Cardiology ◽

10.1016/j.ijcard.2019.10.030 ◽

2020 ◽

Vol 300 ◽

pp. 132-136 ◽

Cited By ~ 2

Author(s):

M.A. Isorni ◽

D. Martins ◽

N. Ben Moussa ◽

S. Monnot ◽

N. Boddaert ◽

...

Keyword(s):

Tetralogy Of Fallot ◽

4D Flow Mri ◽

4D Flow ◽

Pulmonary Flow ◽

Flow Mri ◽

Tetralogy Of Fallot Repair

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Abstract 15290: 4D-flow MRI Intracardiac Flow Hemodynamic Patterns Can Phenotype Different Subtypes of Pulmonary Hypertension

Circulation ◽

10.1161/circ.142.suppl_3.15290 ◽

2020 ◽

Vol 142 (Suppl_3) ◽

Author(s):

Lexie K Ross ◽

Alex J Barker ◽

Benjamin S Frank ◽

Kendall S Hunter ◽

Gareth Morgan ◽

...

Keyword(s):

Diastolic Dysfunction ◽

Type I ◽

4D Flow Mri ◽

4D Flow ◽

Type Iii ◽

Flow Mri ◽

Intracardiac Flow ◽

Pulmonary Arterial ◽

And Function ◽

Functional Indices

Introduction: Idiopathic Pulmonary Arterial Hypertension (PH-Type I) and PH due to pulmonary disease (PH-Type III) arise from different pathophysiologic processes, yet they both culminate in increased right ventricular (RV) afterload and eventual RV failure. Previous work has demonstrated that 4D-Flow MRI-derived intracardiac vorticity (ω) correlates with markers of ventricular interdependency and diastolic dysfunction in PH. However, no investigation has attempted to use both ω and standard markers of ventricular function to phenotype PH subgroups. Hypothesis: 4D-Flow MRI can detect differences in diastolic dysfunction that make it possible to phenotype patients with Type I and Type III PH. Methods: Type I PH patients (n=12, mean age 61yrs), Type III PH patients (n=15, mean age 63yrs), and healthy controls (n=10, mean age 58yrs) underwent standard cardiac MRI as well as 4D-Flow MRI to determine RV intracardiac flow markers including early (ω-E) and late (ω-A) diastolic vorticity. Standard MRI-based RV and LV size and function markers were also collected. Results: ω-E was decreased in the Type I PH group compared to the Type III PH group (P=0.035) and to controls (P<0.001). There was no difference in ω-E between the Type III group and controls (P=0.216). RVEF was decreased in both the Type I (P<0.001) and Type III (P=0.012) group compared to controls. There was no difference in RVEF between the Type I and Type III groups (P=0.917). RVEDV was increased in both the Type I (P=0.008) and Type III (P=0.006) groups compared to controls. No significant differences were noted between groups when assessing (ω-A) and other RV or LV standard volume and functional indices. Conclusion: Our results indicate that 4D-Flow MRI can distinguish among different PH subtypes using intracardiac diastolic vorticity. Comparative studies with standard echocardiography and catheterization are necessary to assess the sensitivity of 4D-Flow MRI to detect diastolic dysfunction.

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