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Schäfer M, Ivy DD, Abman SH, Stenmark K, Browne LP, Barker AJ, Mitchell MB, Morgan GJ, Wilson N, Shah A, Kollengode M, Naresh N, Fonseca B, DiMaria M, Buckner JK, Hunter KS, Kheyfets V, Fenster BE, Truong U. Differences in pulmonary arterial flow hemodynamics between children and adults with pulmonary arterial hypertension as assessed by 4D-flow CMR studies. Am J Physiol Heart Circ Physiol 2019; 316:H1091-H1104. [PMID: 30822118 PMCID: PMC7327229 DOI: 10.1152/ajpheart.00802.2018] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Despite different developmental and pathological processes affecting lung vascular remodeling in both patient populations, differences in 4D MRI findings between children and adults with PAH have not been studied. The purpose of this study was to compare flow hemodynamic state, including flow-mediated shear forces, between pediatric and adult patients with PAH matched by severity of pulmonary vascular resistance index (PVRi). Adults (n = 10) and children (n = 10) with PAH matched by pulmonary vascular resistance index (PVRi) and healthy adult (n = 10) and pediatric (n = 10) subjects underwent comprehensive 4D-flow MRI to assess peak systolic wall shear stress (WSSmax) measured in the main (MPA), right (RPA), and left pulmonary arteries (LPA), viscous energy loss (EL) along the MPA-RPA and MPA-LPA tract, and qualitative analysis of secondary flow hemodynamics. WSSmax was decreased in all pulmonary vessels in children with PAH when compared with the same age group (all P < 0.05). Similarly, WSSmax was decreased in all pulmonary vessels in adult PAH patients when compared with healthy adult subjects (all P < 0.01). Average EL was increased in adult patients with PAH when compared with the same age group along both MPA-RPA (P = 0.020) and MPA-LPA (P = 0.025) tracts. There were no differences in EL indices between adults and pediatric patients. Children and adult patients with PAH have decreased shear hemodynamic forces. However, pathological flow hemodynamic formations appear to be more consistent in adult patients, whereas flow hemodynamic abnormalities appear to be more variable in children with PAH for comparable severity of PVRi. NEW & NOTEWORTHY Both children and adult patients with PAH have decreased shear hemodynamic forces inside the pulmonary arteries associated with the degree of vessel dilation and stiffness. These differences also exist between healthy normotensive children and adults. However, pathological flow hemodynamic formations appear to more uniform in adult patients, whereas in children with PAH flow, hemodynamic abnormalities appear to be more variable. Pathological flow formations appear not to have a major effect on viscous energy loss associated with the flow conduction through proximal pulmonary arteries.
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Affiliation(s)
- Michal Schäfer
- Division of Pediatric Cardiology, Heart Institute, Children's Hospital Colorado, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado
| | - D Dunbar Ivy
- Division of Pediatric Cardiology, Heart Institute, Children's Hospital Colorado, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado
| | - Steven H Abman
- Division of Pulmonology, Breathing Institute, University of Colorado Denver Anschutz Medical Campus , Aurora, Colorado
| | - Kurt Stenmark
- Developmental Lung Biology and Cardiovascular Pulmonary Research Laboratories, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado
| | - Lorna P Browne
- Department of Radiology, Children's Hospital Colorado, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado
| | - Alex J Barker
- Department of Radiology, Children's Hospital Colorado, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado
| | - Max B Mitchell
- Department of Surgery, Pediatric Heart Surgery, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado
| | - Gareth J Morgan
- Division of Pediatric Cardiology, Heart Institute, Children's Hospital Colorado, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado
| | - Neil Wilson
- Division of Pediatric Cardiology, Heart Institute, Children's Hospital Colorado, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado
| | - Anar Shah
- Division of Pediatric Cardiology, Heart Institute, Children's Hospital Colorado, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado
| | - Madhukar Kollengode
- Division of Pediatric Cardiology, Heart Institute, Children's Hospital Colorado, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado
| | - Nivedita Naresh
- Department of Radiology, Children's Hospital Colorado, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado
| | - Brian Fonseca
- Division of Pediatric Cardiology, Heart Institute, Children's Hospital Colorado, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado
| | - Michael DiMaria
- Division of Pediatric Cardiology, Heart Institute, Children's Hospital Colorado, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado
| | - J Kern Buckner
- Division of Cardiology, National Jewish Health , Denver, Colorado
| | - Kendall S Hunter
- Division of Pediatric Cardiology, Heart Institute, Children's Hospital Colorado, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado
| | - Vitaly Kheyfets
- Department of Bioengineering, University of Colorado Denver , Aurora, Colorado
| | - Brett E Fenster
- Division of Cardiology, National Jewish Health , Denver, Colorado
| | - Uyen Truong
- Division of Pediatric Cardiology, Heart Institute, Children's Hospital Colorado, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado
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Schäfer M, Humphries S, Stenmark KR, Kheyfets VO, Buckner JK, Hunter KS, Fenster BE. 4D-flow cardiac magnetic resonance-derived vorticity is sensitive marker of left ventricular diastolic dysfunction in patients with mild-to-moderate chronic obstructive pulmonary disease. Eur Heart J Cardiovasc Imaging 2019; 19:415-424. [PMID: 28460004 DOI: 10.1093/ehjci/jex069] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 03/17/2017] [Indexed: 12/20/2022] Open
Abstract
Aims To investigate the possibility that vorticity assessed by four-dimensional flow cardiac magnetic resonance (4D-Flow CMR) in the left ventricle of patients with mild-to-moderate chronic obstructive pulmonary disease (COPD) is a potential marker of early LV diastolic dysfunction (LVDD) and more sensitive than standard echocardiography, and whether changes in vorticity are associated with quantitative computed tomography (CT) and clinical markers of COPD, and right ventricular (RV) echocardiographic markers indicative of ventricular interdependency. Methods and results Sixteen COPD patients with presumptive LVDD and 10 controls underwent same-day 4D-Flow CMR and Doppler echocardiography to quantify early and late diastolic vorticity as well as standard evaluation for LVDD. Furthermore, all patients underwent detailed CT analysis for COPD markers including percent emphysema and air trapping. The 4D-Flow CMR derived diastolic vorticity measures were correlated with CT measures, standard clinical and CMR markers, and echocardiographic diastolic RV metrics. Early diastolic vorticity was significantly reduced in COPD patients (P < 0.0001) with normal left ventricular (LV) mass, geometry, systolic function, and no or mild signs of Doppler LVDD when compared with controls. Vorticity significantly differentiated COPD patients without echocardiographic signs of LVDD (n = 11) from controls (P < 0.0001), and from COPD patients with stage I LVDD (n = 5) (P < 0.0180). Vorticity markers significantly correlated with CT computed measures, CMR-derived RV ejection fraction, echocardiographic RV diastolic metrics, and 6-minute walk test. Conclusion 4D-Flow CMR derived diastolic vorticity is reduced in patients with mild-to-moderate COPD and no or mild signs of LVDD, implying early perturbations in the LV flow domain preceding more obvious mechanical changes (i.e. stiffening and dilation). Furthermore, reduced LV vorticity appears to be driven by COPD induced changes in lung tissue and parallel RV dysfunction.
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Affiliation(s)
- Michal Schäfer
- Department of Cardiology, National Jewish Health, 1400 Jackson St, Denver, CO 80206, USA.,Department of Bioengineering, University of Colorado Denver, Anschutz Medical Campus, Research 2 - Building P15, 12700 E 19th Avenue, Aurora, CO 80045-2560, USA
| | - Stephen Humphries
- Department of Radiology, National Jewish Health, 1400 Jackson St, Denver, CO 80206, USA
| | - Kurt R Stenmark
- Division of Pediatrics, Department of Critical Care, University of Colorado, Anschutz Medical Campus, 212700 E. 19th Avenue, Box B131, Aurora, CO 80045, USA
| | - Vitaly O Kheyfets
- Department of Cardiology, National Jewish Health, 1400 Jackson St, Denver, CO 80206, USA.,Department of Bioengineering, University of Colorado Denver, Anschutz Medical Campus, Research 2 - Building P15, 12700 E 19th Avenue, Aurora, CO 80045-2560, USA
| | - J Kern Buckner
- Department of Cardiology, National Jewish Health, 1400 Jackson St, Denver, CO 80206, USA
| | - Kendall S Hunter
- Department of Cardiology, National Jewish Health, 1400 Jackson St, Denver, CO 80206, USA.,Department of Bioengineering, University of Colorado Denver, Anschutz Medical Campus, Research 2 - Building P15, 12700 E 19th Avenue, Aurora, CO 80045-2560, USA
| | - Brett E Fenster
- Department of Cardiology, National Jewish Health, 1400 Jackson St, Denver, CO 80206, USA
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Schäfer M, Barker AJ, Kheyfets V, Stenmark KR, Crapo J, Yeager ME, Truong U, Buckner JK, Fenster BE, Hunter KS. Helicity and Vorticity of Pulmonary Arterial Flow in Patients With Pulmonary Hypertension: Quantitative Analysis of Flow Formations. J Am Heart Assoc 2017; 6:JAHA.117.007010. [PMID: 29263034 PMCID: PMC5779020 DOI: 10.1161/jaha.117.007010] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Background Qualitative and quantitative flow hemodynamic indexes have been shown to reflect right ventricular (RV) afterload and function in pulmonary hypertension (PH). We aimed to quantify flow hemodynamic formations in pulmonary arteries using 4‐dimensional flow cardiac magnetic resonance imaging and the spatial velocity derivatives helicity and vorticity in a heterogeneous PH population. Methods and Results Patients with PH (n=35) and controls (n=10) underwent 4‐dimensional flow magnetic resonance imaging study for computation of helicity and vorticity in the main pulmonary artery (MPA), the right pulmonary artery, and the RV outflow tract. Helicity and vorticity were correlated with standard RV volumetric and functional indexes along with MPA stiffness assessed by measuring relative area change. Patients with PH had a significantly decreased helicity in the MPA (8 versus 32 m/s2; P<0.001), the right pulmonary artery (24 versus 50 m/s2; P<0.001), and the RV outflow tract–MPA unit (15 versus 42 m/s2; P<0.001). Vorticity was significantly decreased in patients with PH only in the right pulmonary artery (26 versus 45 1/s; P<0.001). Total helicity computed correlated with the cardiac magnetic resonance imaging–derived ventricular‐vascular coupling (−0.927; P<0.000), the RV ejection fraction (0.865; P<0.0001), cardiac output (0.581; P<0.0001), mean pulmonary arterial pressure (−0.581; P=0.0008), and relative area change measured at the MPA (0.789; P<0.0001). Conclusions The flow hemodynamic character in patients with PH assessed via quantitative analysis is considerably different when compared with healthy and normotensive controls. A strong association between helicity in pulmonary arteries and ventricular‐vascular coupling suggests a relationship between the mechanical and flow hemodynamic domains.
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Affiliation(s)
- Michal Schäfer
- Division of Cardiology, National Jewish Health, Denver, CO .,Division of Cardiology, Children's Hospital Colorado, Aurora, CO.,Department of Bioengineering, University of Colorado Denver
- Anschutz Medical Campus, Denver, CO
| | - Alex J Barker
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Vitaly Kheyfets
- Department of Bioengineering, University of Colorado Denver
- Anschutz Medical Campus, Denver, CO
| | - Kurt R Stenmark
- Department of Bioengineering, University of Colorado Denver
- Anschutz Medical Campus, Denver, CO.,Pediatric Division, Department of Critical Care and Pulmonary Medicine, University of Colorado Denver
- Anschutz Medical Campus, Denver, CO
| | - James Crapo
- Division of Pulmonary Medicine, National Jewish Health, Denver, CO
| | - Michael E Yeager
- Department of Bioengineering, University of Colorado Denver
- Anschutz Medical Campus, Denver, CO
| | - Uyen Truong
- Division of Cardiology, National Jewish Health, Denver, CO.,Department of Bioengineering, University of Colorado Denver
- Anschutz Medical Campus, Denver, CO
| | - J Kern Buckner
- Division of Cardiology, National Jewish Health, Denver, CO
| | | | - Kendall S Hunter
- Division of Cardiology, National Jewish Health, Denver, CO.,Department of Bioengineering, University of Colorado Denver
- Anschutz Medical Campus, Denver, CO
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Schäfer M, Kheyfets VO, Barker AJ, Stenmark K, Hunter KS, McClatchey PM, Buckner JK, Reece TB, Jazaeri O, Fenster BE. Reduced shear stress and associated aortic deformation in the thoracic aorta of patients with chronic obstructive pulmonary disease. J Vasc Surg 2017; 68:246-253. [PMID: 28986100 DOI: 10.1016/j.jvs.2017.06.110] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 06/23/2017] [Indexed: 01/16/2023]
Abstract
OBJECTIVE Central aortic stiffness and chronic obstructive pulmonary disease (COPD) are associated with increased incidence of devastating aortopathies. However, the exact mechanism leading to elevated aortic stiffness in patients with COPD is unknown. The purpose of this study was to quantify flow and shear hemodynamic indices, known markers of vascular remodeling, in the thoracic aorta of patients with mild to moderate COPD (n = 16) and to compare these results with an age-matched control group (n = 10). METHODS Four-dimensional flow magnetic resonance imaging has been applied to measure hemodynamic wall shear stress (WSS) at four specific planes along the ascending aorta, aortic arch, and proximal descending aorta for all subjects. Peak systolic WSS and time-averaged WSS, which respectively reflect magnitude and temporal shear variability, were calculated at standardized planes. Aortic deformation was measured by means of relative area change (RAC) at the midlevel of the ascending and descending aorta. RESULTS Compared with controls, patients with COPD had significantly reduced RAC in the mid ascending aorta (9% vs 18%; P < .0001) and descending aorta (15% vs 19%; P = .0206). Peak systolic WSS in COPD patients was significantly reduced in all considered planes, with the most dramatic difference occurring in the descending aorta (0.46 vs 0.86 N/m2; P < .0001). Peak systolic WSS and time-averaged WSS were both significantly correlated with aortic RAC at each evaluated plane. CONCLUSIONS Reduced flow shear metrics assessed at specific aortic regions correlated with RAC, a marker of aortic stiffness. Reduced hemodynamic WSS may then contribute to central aortic stiffening and perpetuate the risk for development of severe aortopathy.
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Affiliation(s)
- Michal Schäfer
- Department of Cardiology, National Jewish Health, Denver, Colo; Department of Bioengineering, University of Colorado Denver | Anschutz Medical Campus, Aurora, Colo.
| | - Vitaly O Kheyfets
- Department of Cardiology, National Jewish Health, Denver, Colo; Department of Bioengineering, University of Colorado Denver | Anschutz Medical Campus, Aurora, Colo
| | - Alex J Barker
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Ill
| | - Kurt Stenmark
- Cardiovascular Pulmonary Research Laboratories, Department of Medicine and Pediatrics, University of Colorado Denver | Anschutz Medical Campus, Aurora, Colo
| | - Kendall S Hunter
- Department of Cardiology, National Jewish Health, Denver, Colo; Department of Bioengineering, University of Colorado Denver | Anschutz Medical Campus, Aurora, Colo
| | - P Mason McClatchey
- Department of Bioengineering, University of Colorado Denver | Anschutz Medical Campus, Aurora, Colo
| | - J Kern Buckner
- Department of Cardiology, National Jewish Health, Denver, Colo
| | - T Brett Reece
- Division of Cardiothoracic Surgery, Department of Surgery, University of Colorado Denver | Anschutz Medical Campus, Aurora, Colo
| | - Omid Jazaeri
- Division of Vascular and Endovascular Therapy, Department of Surgery, University of Colorado Denver | Anschutz Medical Campus, Aurora, Colo
| | - Brett E Fenster
- Department of Cardiology, National Jewish Health, Denver, Colo
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Kheyfets VO, Schafer M, Podgorski CA, Schroeder JD, Browning J, Hertzberg J, Buckner JK, Hunter KS, Shandas R, Fenster BE. 4D magnetic resonance flow imaging for estimating pulmonary vascular resistance in pulmonary hypertension. J Magn Reson Imaging 2016; 44:914-22. [PMID: 27173445 DOI: 10.1002/jmri.25251] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 03/07/2016] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To develop an estimate of pulmonary vascular resistance (PVR) using blood flow measurements from 3D velocity-encoded phase contract magnetic resonance imaging (here termed 4D MRI). MATERIALS AND METHODS In all, 17 patients with pulmonary hypertension (PH) and five controls underwent right heart catheterization (RHC), 4D and 2D Cine MRI (1.5T) within 24 hours. MRI was used to compute maximum spatial peak systolic vorticity in the main pulmonary artery (MPA) and right pulmonary artery (RPA), cardiac output, and relative area change in the MPA. These parameters were combined in a four-parameter multivariate linear regression model to arrive at an estimate of PVR. Agreement between model predicted and measured PVR was also evaluated using Bland-Altman plots. Finally, model accuracy was tested by randomly withholding a patient from regression analysis and using them to validate the multivariate equation. RESULTS A decrease in vorticity in the MPA and RPA were correlated with an increase in PVR (MPA: R(2) = 0.54, P < 0.05; RPA: R(2) = 0.75, P < 0.05). Expanding on this finding, we identified a multivariate regression equation that accurately estimates PVR (R(2) = 0.94, P < 0.05) across severe PH and normotensive populations. Bland-Altman plots showed 95% of the differences between predicted and measured PVR to lie within 1.49 Wood units. Model accuracy testing revealed a prediction error of ∼20%. CONCLUSION A multivariate model that includes MPA relative area change and flow characteristics, measured using 4D and 2D Cine MRI, offers a promising technique for noninvasively estimating PVR in PH patients. J. MAGN. RESON. IMAGING 2016;44:914-922.
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Affiliation(s)
- Vitaly O Kheyfets
- University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA. .,National Jewish Health, Denver, Colorado, USA.
| | - Michal Schafer
- University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.,National Jewish Health, Denver, Colorado, USA
| | | | - Joyce D Schroeder
- University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | | | | | | | - Kendal S Hunter
- University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.,National Jewish Health, Denver, Colorado, USA
| | - Robin Shandas
- University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
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Schäfer M, Browning J, Schroeder JD, Shandas R, Kheyfets VO, Buckner JK, Hunter KS, Hertzberg JR, Fenster BE. Vorticity is a marker of diastolic ventricular interdependency in pulmonary hypertension. Pulm Circ 2016; 6:46-54. [PMID: 27162613 PMCID: PMC4860542 DOI: 10.1086/685052] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Our objective was to determine whether left ventricular (LV) vorticity (ω), the local spinning motion of a fluid element, correlated with markers of ventricular interdependency in pulmonary hypertension (PH). Maladaptive ventricular interdependency is associated with interventricular septal shift, impaired LV performance, and poor outcomes in PH patients, yet the pathophysiologic mechanisms underlying fluid-structure interactions in ventricular interdependency are incompletely understood. Because conformational changes in chamber geometry affect blood flow formations and dynamics, LV ω may be a marker of LV-RV (right ventricular) interactions in PH. Echocardiography was performed for 13 PH patients and 10 controls for assessment of interdependency markers, including eccentricity index (EI), and biventricular diastolic dysfunction, including mitral valve (MV) and tricuspid valve (TV) early and late velocities (E and A, respectively) as well as MV septal and lateral early tissue Doppler velocities (e'). Same-day 4-dimensional cardiac magnetic resonance was performed for LV E (early)-wave ω measurement. LV E-wave ω was significantly decreased in PH patients (P = 0.008) and correlated with diastolic EI (Rho = -0.53, P = 0.009) as well as with markers of LV diastolic dysfunction, including MV E(Rho = 0.53, P = 0.011), E/A (Rho = 0.56, P = 0.007), septal e' (Rho = 0.63, P = 0.001), and lateral e' (Rho = 0.57, P = 0.007). Furthermore, LV E-wave ω was associated with indices of RV diastolic dysfunction, including TV e' (Rho = 0.52, P = 0.012) and TV E/A (Rho = 0.53, P = 0.009). LV E-wave ω is decreased in PH and correlated with multiple echocardiographic markers of ventricular interdependency. LV ω may be a novel marker for fluid-tissue biomechanical interactions in LV-RV interdependency.
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Affiliation(s)
- Michal Schäfer
- Department of Cardiology, National Jewish Health, University of Colorado, Denver, Colorado, USA; Department of Bioengineering, University of Colorado, Anschutz Medical Campus, Denver, Colorado, USA
| | - James Browning
- Department of Mechanical Engineering, University of Colorado, Boulder, Colorado, USA
| | - Joyce D Schroeder
- Department of Radiology, National Jewish Health, University of Colorado, Denver, Colorado, USA
| | - Robin Shandas
- Department of Bioengineering, University of Colorado, Anschutz Medical Campus, Denver, Colorado, USA
| | - Vitaly O Kheyfets
- Department of Bioengineering, University of Colorado, Anschutz Medical Campus, Denver, Colorado, USA
| | - J Kern Buckner
- Department of Cardiology, National Jewish Health, University of Colorado, Denver, Colorado, USA
| | - Kendall S Hunter
- Department of Bioengineering, University of Colorado, Anschutz Medical Campus, Denver, Colorado, USA
| | - Jean R Hertzberg
- Department of Mechanical Engineering, University of Colorado, Boulder, Colorado, USA
| | - Brett E Fenster
- Department of Cardiology, National Jewish Health, University of Colorado, Denver, Colorado, USA
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Schäfer M, Kheyfets VO, Schroeder JD, Dunning J, Shandas R, Buckner JK, Browning J, Hertzberg J, Hunter KS, Fenster BE. Main pulmonary arterial wall shear stress correlates with invasive hemodynamics and stiffness in pulmonary hypertension. Pulm Circ 2016; 6:37-45. [PMID: 27076906 PMCID: PMC4809665 DOI: 10.1086/685024] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Pulmonary hypertension (PH) is associated with proximal pulmonary arterial remodeling characterized by increased vessel diameter, wall thickening, and stiffness. In vivo assessment of wall shear stress (WSS) may provide insights into the relationships between pulmonary hemodynamics and vascular remodeling. We investigated the relationship between main pulmonary artery (MPA) WSS and pulmonary hemodynamics as well as markers of stiffness. As part of a prospective study, 17 PH patients and 5 controls underwent same-day four-dimensional flow cardiac magnetic resonance imaging (4-D CMR) and right heart catheterization. Streamwise velocity profiles were generated in the cross-sectional MPA in 45° increments from velocity vector fields determined by 4-D CMR. WSS was calculated as the product of hematocrit-dependent viscosity and shear rate generated from the spatial gradient of the velocity profiles. In-plane average MPA WSS was significantly decreased in the PH cohort compared with that in controls (0.18 ± 0.07 vs. 0.32 ± 0.08 N/m(2); P = 0.01). In-plane MPA WSS showed strong inverse correlations with multiple hemodynamic indices, including pulmonary resistance (ρ = -0.74, P < 0.001), mean pulmonary pressure (ρ = -0.64, P = 0.006), and elastance (ρ = -0.70, P < 0.001). In addition, MPA WSS had significant associations with markers of stiffness, including capacitance (ρ = 0.67, P < 0.001), distensibility (ρ = 0.52, P = 0.013), and elastic modulus (ρ = -0.54, P = 0.01). In conclusion, MPA WSS is decreased in PH and is significantly associated with invasive hemodynamic indices and markers of stiffness. 4-D CMR-based assessment of WSS may represent a novel methodology to study blood-vessel wall interactions in PH.
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Affiliation(s)
- Michal Schäfer
- Division of Cardiology, National Jewish Health, Denver, Colorado, USA; Department of Bioengineering, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado, USA
| | - Vitaly O Kheyfets
- Division of Cardiology, National Jewish Health, Denver, Colorado, USA; Department of Bioengineering, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado, USA
| | - Joyce D Schroeder
- Division of Radiology, National Jewish Health, Denver, Colorado, USA
| | - Jamie Dunning
- Department of Bioengineering, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado, USA
| | - Robin Shandas
- Department of Bioengineering, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado, USA
| | - J Kern Buckner
- Division of Cardiology, National Jewish Health, Denver, Colorado, USA
| | - James Browning
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, Colorado, USA
| | - Jean Hertzberg
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, Colorado, USA
| | - Kendall S Hunter
- Department of Bioengineering, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado, USA; BEF and KSH are co-senior authors
| | - Brett E Fenster
- Division of Cardiology, National Jewish Health, Denver, Colorado, USA; BEF and KSH are co-senior authors
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Fenster BE, Browning J, Schroeder JD, Schafer M, Podgorski CA, Smyser J, Silveira LJ, Buckner JK, Hertzberg JR. Vorticity is a marker of right ventricular diastolic dysfunction. Am J Physiol Heart Circ Physiol 2015; 309:H1087-93. [PMID: 26254331 DOI: 10.1152/ajpheart.00278.2015] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 08/04/2015] [Indexed: 11/22/2022]
Abstract
Right ventricular diastolic dysfunction (RVDD) is an important prognostic indicator in pulmonary arterial hypertension (PAH). RV vortex rings have been observed in healthy subjects, but their significance in RVDD is unknown. Vorticity, the local spinning motion of an element of fluid, may be a sensitive measure of RV vortex dynamics. Using four-dimensional (4D) flow cardiac magnetic resonance imaging (CMR), we investigated the relationship between right heart vorticity with echocardiographic indexes of RVDD. Thirteen (13) PAH subjects and 10 controls underwent same-day 4D flow CMR and echocardiography. RV diastolic function was assessed using trans-tricuspid valve (TV) early (E) and late (A) velocities, E/A ratio, and e' and a' tissue Doppler velocities. RV and right atrial (RA) integrated mean vorticity was calculated for E and A-wave filling periods using 4D datasets. Compared with controls, A-wave vorticity was significantly increased in RVDD subjects in both the RV [2343 (1,559-3,295) vs. 492 (267-2,649) 1/s, P = 0.028] and RA [30 (27-44) vs. 9 (5-27) 1/s, P = 0.005]. RA E vorticity was significantly decreased [13 (7-22) vs. 28 (15-31) 1/s, P = 0.038] in RVDD. E-wave vorticity correlated TV e', E-,and TV E/A (P < 0.05), and A-wave vorticity associated with both TV A and E/A (P < 0.02). RVDD is associated with alterations in E- and A-wave vorticity, and vorticity correlates with multiple echocardiographic markers of RVDD. Vorticity may be a robust noninvasive research tool for the investigation of RV fluid and tissue mechanical interactions in PAH.
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Affiliation(s)
- Brett E Fenster
- Division of Cardiology, National Jewish Health, Denver, Colorado;
| | - James Browning
- Department of Mechanical Engineering, University of Colorado, Boulder, Colorado
| | - Joyce D Schroeder
- Division of Cardiology, National Jewish Health, Denver, Colorado; Department of Mechanical Engineering, University of Colorado, Boulder, Colorado; Division of Radiology, National Jewish Health, Denver, Colorado; and Division of Biostatistics and Bioinformatics, National Jewish Health, Denver, Colorado
| | - Michal Schafer
- Division of Cardiology, National Jewish Health, Denver, Colorado
| | | | - Jamie Smyser
- Division of Radiology, National Jewish Health, Denver, Colorado; and Division of Biostatistics and Bioinformatics, National Jewish Health, Denver, Colorado
| | - Lori J Silveira
- Division of Cardiology, National Jewish Health, Denver, Colorado; Department of Mechanical Engineering, University of Colorado, Boulder, Colorado; Division of Radiology, National Jewish Health, Denver, Colorado; and Division of Biostatistics and Bioinformatics, National Jewish Health, Denver, Colorado
| | - J Kern Buckner
- Division of Cardiology, National Jewish Health, Denver, Colorado
| | - Jean R Hertzberg
- Department of Mechanical Engineering, University of Colorado, Boulder, Colorado
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Schafer M, Kheyfets V, Schroeder J, Podgorski C, Dunning J, Buckner JK, Hunter K, Fenster B. PULMONARY ARTERY WALL SHEAR STRESS IS A MARKER OF PULMONARY VASCULAR HEMODYNAMICS. J Am Coll Cardiol 2015. [DOI: 10.1016/s0735-1097(15)61560-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Fenster B, Smyser J, Buckner JK, Schroeder J, Lasalvia L. GALECTIN 3: A POTENTIAL BIOMARKER FOR PULMONARY ARTERIAL HYPERTENSION. J Am Coll Cardiol 2014. [DOI: 10.1016/s0735-1097(14)61506-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Fenster BE, Lasalvia L, Schroeder JD, Smyser J, Silveira LJ, Buckner JK, Brown KK. Cystatin C: a potential biomarker for pulmonary arterial hypertension. Respirology 2014; 19:583-9. [PMID: 24628703 DOI: 10.1111/resp.12259] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 12/30/2013] [Accepted: 01/14/2014] [Indexed: 12/22/2022]
Abstract
BACKGROUND AND OBJECTIVE Cystatin C (CysC), a novel marker of renal function, predicts left heart failure and cardiovascular mortality. The hypothesis that serum CysC levels correlate with right ventricular (RV) morphology, function and pressure in pulmonary arterial hypertension (PAH) was tested. METHODS As part of a prospective study, 14 PAH subjects and 10 matched controls underwent same-day echocardiography, cardiac magnetic resonance imaging (CMR), and phlebotomy for CysC, brain natriuretic peptide (BNP), and N-terminal BNP (NT-ProBNP). RV ejection fraction (RVEF), end-diastolic volume, end-systolic volume and mass were calculated using CMR. RV systolic pressure (RVSP), strain and diastolic function (including tricuspid valve (TV) E velocity, A velocity, e' velocity, E/A ratio and E/e' ratio) were assessed using echocardiography. RESULTS RVSP was significantly elevated in PAH subjects versus controls (57 ± 17 vs. 28 ± 8 mm Hg, P < 0.0001). CysC was abnormally elevated in the PAH cohort when compared with controls (1.00 ± 0.23 vs 0.78 ± 0.05 mg/L, P = 0.001). CysC positively correlated with RVSP (rho 0.61, P = 0.002), RV end-diastolic volume (rho 0.50, P = 0.01), RV end-systolic volume (rho 0.58, P = 0.003), mass index (rho 0.66, P = 0.0004), strain (rho 0.51, P = 0.01) and strain rate (rho 0.51, P = 0.01) and negatively correlated with RVEF (rho -0.58, P = 0.003) and TV e' (rho -0.75, P < 0.0001). The same correlations with BNP and NT-ProBNP were comparable with CysC. CONCLUSIONS In a small cohort, CysC accurately correlates with RV pressure, function and morphology. CysC may represent a novel PAH biomarker.
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Affiliation(s)
- Brett E Fenster
- Division of Cardiology, National Jewish Health, Denver, Colorado, USA
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Honeyman A, Browning J, Hertzberg J, Schroeder JD, Stalder AF, Kern Buckner J, Fenster B. Vorticity for the assessment of pulmonary vascular hemodynamics in pulmonary arterial hypertension. J Cardiovasc Magn Reson 2014. [PMCID: PMC4042372 DOI: 10.1186/1532-429x-16-s1-p15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Fenster BE, Curran-Everett D, Freeman AM, Weinberger HD, Kern Buckner J, Carroll JD. Saline Contrast Echocardiography for the Detection of Patent Foramen Ovale in Hypoxia: A Validation Study Using Intracardiac Echocardiography. Echocardiography 2013; 31:420-7. [DOI: 10.1111/echo.12403] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Affiliation(s)
| | - Douglas Curran-Everett
- Division of Biostatistics and Bioinformatics; National Jewish Health; Denver Colorado
- Division of Biostatistics and Informatics; Colorado School of Public Health; Aurora Colorado
| | | | | | - J. Kern Buckner
- Division of Cardiology; National Jewish Health; Denver Colorado
| | - John D. Carroll
- Division of Cardiology; University of Colorado; Aurora Colorado
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Fenster BE, Nguyen BH, Buckner JK, Freeman AM, Carroll JD. Effectiveness of percutaneous closure of patent foramen ovale for hypoxemia. Am J Cardiol 2013; 112:1258-62. [PMID: 23871675 DOI: 10.1016/j.amjcard.2013.06.022] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Revised: 06/11/2013] [Accepted: 06/11/2013] [Indexed: 11/16/2022]
Abstract
The aim of this study was to evaluate the ability of percutaneous patent foramen ovale (PFO) closure to improve systemic hypoxemia. Although PFO-mediated right-to-left shunt (RTLS) is associated with hypoxemia, the ability of percutaneous closure to ameliorate hypoxemia is unknown. Between 2004 and 2009, 97 patients who underwent PFO closure for systemic hypoxemia and dyspnea that was disproportionate to underlying lung disease were included for evaluation. All patients exhibited PFO-mediated RTLS as determined by agitated saline echocardiography. Procedural success was defined as implantation of a device without major complications and mild or no residual shunt at 6 months. Clinical success was defined as a composite of an improvement in New York Heart Association (NYHA) functional class, reduction of dyspnea symptoms, or decreased oxygen requirement. Procedural success was achieved in 96 of 97 (99%), and clinical success was achieved in 68 of 97 (70%). The presence of any moderate or severe interatrial shunt by agitated saline study (odds ratio [OR] = 4.7; p <0.024), NYHA class at referral (OR = 2.9; p <0.0087), and 10-year increase in age (OR = 1.8; p <0.0017) increased likelihood of clinical success. In contrast, a pulmonary comorbidity (OR = 0.18; p <0.005) and male gender (OR = 0.30; p <0.017) decreased the likelihood of success. In conclusion, based on the largest single-center experience of patients referred for PFO closure for systemic hypoxemia, PFO closure was a mechanically effective procedure with an associated improvement in echocardiographic evidence of RTLS, NYHA functional class, and oxygen requirement.
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Affiliation(s)
- Brett E Fenster
- Division of Cardiology, National Jewish Health, Denver, Colorado.
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Fenster B, Smyser J, Schroeder J, Buckner JK, Lasalvia L. CYSTATIN C: A NOVEL BIOMARKER FOR PULMONARY ARTERIAL HYPERTENSION. J Am Coll Cardiol 2013. [DOI: 10.1016/s0735-1097(13)61300-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Fenster B, Browning J, Stalder AF, Glielmi C, Silveira L, Buckner JK, Kluiber A, Schroeder JD, Hertzberg J. Vorticity for the assessment of right ventricular diastolic dysfunction using 4D flow CMR. J Cardiovasc Magn Reson 2013. [PMCID: PMC3559992 DOI: 10.1186/1532-429x-15-s1-p8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Freeman AM, Fenster BE, Weinberger HD, Buckner JK, Lynch D. Hypoxia caused by persistent left superior vena cava connecting to the left atrium a rare clinical entity. Tex Heart Inst J 2012; 39:662-664. [PMID: 23109762 PMCID: PMC3461683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We relate the case of a 40-year-old man with a history of premature birth and dextroposition of the heart who presented for an evaluation of persistent hypoxia. An unrevealing pulmonary evaluation and agitated-saline echocardiogram led to cardiac magnetic resonance imaging. This revealed a very unusual finding: a persistent left superior vena cava with insertion into the left atrium and a small connecting vein between the right and left superior venae cavae. The implications, embryology, and pathogenesis of this rare condition are discussed.
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Affiliation(s)
- Andrew M Freeman
- Department of Medicine, Division of Cardiology, National Jewish Health, Denver, Colorado 80207, USA.
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Fenster BE, Freeman AM, Weinberger HD, Buckner JK. Recurrent transient mid-ventricular ballooning. Int J Cardiol 2011; 152:e35-6. [DOI: 10.1016/j.ijcard.2010.10.061] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Accepted: 10/23/2010] [Indexed: 12/18/2022]
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Affiliation(s)
- D W Krueger
- Division of Cardiology, University of Colorado Health Sciences Center, Denver 80262
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Lesnefsky EJ, Pacheco J, Adcock K, Buckner JK, Van Benthuysen KM. Thallium scintigraphic evidence of reversible myocardial ischemia caused by anomalous origin of the left main coronary artery from the anterior sinus of Valsalva. Am Heart J 1987; 114:896-7. [PMID: 3661374 DOI: 10.1016/0002-8703(87)90802-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- E J Lesnefsky
- Division of Cardiology, Denver Veterans Administration Medical Center, CO
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Abstract
Quantum and statistical mechanics have been used to determine energy profiles for the SN2 reaction of Cl- + CH3Cl in the gas phase, in aqueous solution, and in liquid DMF. The energy profile in the gas phase has the characteristic double-well form featuring unsymmetrical ion-dipole complexes as minima and a symmetrical transition state. Hydration causes the reaction surface to become almost unimodal and increases the barrier significantly. The reaction profile in DMF is intermediate between those for the gas phase and aqueous solution. The ion-dipole complexes are still free energy minima in DMF. Thus, the reaction in DMF involves initial formation of the complex before the rate-determining step. The computed results are shown to be in good accord with experimental free energies of activation. The same technique has been applied to the addition reaction of OH- + H2C = O in the gas phase and aqueous solution. Ab initio 6-31 + G* calculations indicate that the reaction proceeds essentially without activation in the gas phase. Hydration introduces a substantial energy barrier. The transition state in water has been located at a C-O separation of roughly 2 A. A key finding for both reactions is that the activation barriers induced by hydration result primarily from change in strengths rather than in numbers of solute-water hydrogen bonds along the reaction paths.
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