1
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McLennan D, Schäfer M, Barker AJ, Mitchell MB, Ing RJ, Browne LP, Ivy DD, Morgan GJ. Abnormal flow conduction through pulmonary arteries is associated with right ventricular volume and function in patients with repaired tetralogy of Fallot: does flow quality affect afterload? Eur Radiol 2022; 33:302-311. [DOI: 10.1007/s00330-022-09017-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 05/27/2022] [Accepted: 07/04/2022] [Indexed: 11/04/2022]
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2
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Pillalamarri NR, Piskin S, Patnaik SS, Murali S, Finol EA. Patient-Specific Computational Analysis of Hemodynamics in Adult Pulmonary Hypertension. Ann Biomed Eng 2021; 49:3465-3480. [PMID: 34799807 DOI: 10.1007/s10439-021-02884-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 10/29/2021] [Indexed: 11/25/2022]
Abstract
Pulmonary hypertension (PH) is a progressive disease characterized by elevated pressure and vascular resistance in the pulmonary arteries. Nearly 250,000 hospitalizations occur annually in the US with PH as the primary or secondary condition. A definitive diagnosis of PH requires right heart catheterization (RHC) in addition to a chest computed tomography, a walking test, and others. While RHC is the gold standard for diagnosing PH, it is invasive and posseses inherent risks and contraindications. In this work, we characterized the patient-specific pulmonary hemodynamics in silico for diverse PH WHO groups. We grouped patients on the basis of mean pulmonary arterial pressure (mPAP) into three disease severity groups: at-risk ([Formula: see text], denoted with A), mild ([Formula: see text], denoted with M), and severe ([Formula: see text], denoted with S). The pulsatile flow hemodynamics was simulated by evaluating the three-dimensional Navier-Stokes system of equations using a flow solver developed by customizing OpenFOAM libraries (v5.0, The OpenFOAM Foundation). Quasi patient-specific boundary conditions were implemented using a Womersley inlet velocity profile and transient resistance outflow conditions. Hemodynamic indices such as spatially averaged wall shear stress ([Formula: see text]), wall shear stress gradient ([Formula: see text]), time-averaged wall shear stress ([Formula: see text]), oscillatory shear index ([Formula: see text]), and relative residence time ([Formula: see text]), were evaluated along with the clinical metrics pulmonary vascular resistance ([Formula: see text]), stroke volume ([Formula: see text]) and compliance ([Formula: see text]), to assess possible spatiotemporal correlations. We observed statistically significant decreases in [Formula: see text], [Formula: see text], and [Formula: see text], and increases in [Formula: see text] and [Formula: see text] with disease severity. [Formula: see text] was moderately correlated with [Formula: see text] and [Formula: see text] at the mid-notch stage of the cardiac cycle when these indices were computed using the global pulmonary arterial geometry. These results are promising in the context of a long-term goal of identifying computational biomarkers that can serve as surrogates for invasive diagnostic protocols of PH.
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Affiliation(s)
- Narasimha R Pillalamarri
- Department of Mechanical Engineering, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, USA
| | - Senol Piskin
- Department of Mechanical Engineering, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, USA
- Department of Mechanical Engineering, Istinye University, Istanbul, Turkey
| | - Sourav S Patnaik
- Department of Mechanical Engineering, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, USA
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, USA
| | - Srinivas Murali
- Division of Cardiovascular Medicine, Allegheny Health Network, Pittsburgh, PA, USA
| | - Ender A Finol
- Department of Mechanical Engineering, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, USA.
- UTSA/UTHSA Joint Graduate Program in Biomedical Engineering, University of Texas at San Antonio, San Antonio, TX, USA.
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3
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Dong ML, Lan IS, Yang W, Rabinovitch M, Feinstein JA, Marsden AL. Computational simulation-derived hemodynamic and biomechanical properties of the pulmonary arterial tree early in the course of ventricular septal defects. Biomech Model Mechanobiol 2021; 20:2471-2489. [PMID: 34585299 DOI: 10.1007/s10237-021-01519-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 09/12/2021] [Indexed: 01/15/2023]
Abstract
Untreated ventricular septal defects (VSDs) can lead to pulmonary arterial hypertension (PAH) characterized by elevated pulmonary artery (PA) pressure and vascular remodeling, known as PAH associated with congenital heart disease (PAH-CHD). Though previous studies have investigated hemodynamic effects on vascular mechanobiology in late-stage PAH, hemodynamics leading to PAH-CHD initiation have not been fully quantified. We hypothesize that abnormal hemodynamics from left-to-right shunting in early stage VSDs affects PA biomechanical properties leading to PAH initiation. To model PA hemodynamics in healthy, small, moderate, and large VSD conditions prior to the onset of vascular remodeling, computational fluid dynamics simulations were performed using a 3D finite element model of a healthy 1-year-old's proximal PAs and a body-surface-area-scaled 0D distal PA tree. VSD conditions were modeled with increased pulmonary blood flow to represent degrees of left-to-right shunting. In the proximal PAs, pressure, flow, strain, and wall shear stress (WSS) increased with increasing VSD size; oscillatory shear index decreased with increasing VSD size in the larger PA vessels. WSS was higher in smaller diameter vessels and increased with VSD size, with the large VSD condition exhibiting WSS >100 dyn/cm[Formula: see text], well above values typically used to study dysfunctional mechanotransduction pathways in PAH. This study is the first to estimate hemodynamic and biomechanical metrics in the entire pediatric PA tree with VSD severity at the stage leading to PAH initiation and has implications for future studies assessing effects of abnormal mechanical stimuli on endothelial cells and vascular wall mechanics that occur during PAH-CHD initiation and progression.
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Affiliation(s)
- Melody L Dong
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Ingrid S Lan
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Weiguang Yang
- Department of Pediatrics, Stanford University, Stanford, CA, USA
| | | | - Jeffrey A Feinstein
- Department of Pediatrics and Bioengineering, Stanford University, Stanford, CA, USA
| | - Alison L Marsden
- Department of Pediatrics and Bioengineering, Stanford University, Stanford, CA, USA.
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4
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Latus H, Meierhofer C. Role of cardiovascular magnetic resonance in pediatric pulmonary hypertension-novel concepts and imaging biomarkers. Cardiovasc Diagn Ther 2021; 11:1057-1069. [PMID: 34527532 DOI: 10.21037/cdt-20-270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Accepted: 04/15/2020] [Indexed: 11/06/2022]
Abstract
Pulmonary hypertension (PH) in children is a heterogenous disease of the small pulmonary arteries characterized by a progressive increase in pulmonary vascular resistance. Despite adequate medical therapy, long-term pressure overload is frequently associated with a progressive course leading to right ventricular failure and ultimately death. Invasive hemodynamic assessment by cardiac catheterization is crucial for initial diagnosis, risk stratification and therapeutic strategy. Although echocardiography remains the most important imaging modality for the assessment of right ventricular function and pulmonary hemodynamics, cardiovascular magnetic resonance (CMR) has emerged as a valuable non-invasive imaging technique that enables comprehensive evaluation of biventricular performance, blood flow, morphology and the myocardial tissue. In this review, we summarize the principles and applications of CMR in the evaluation of pediatric PH patients and present an update about novel CMR based concepts and imaging biomarkers that may provide further diagnostic, therapeutic and prognostic information.
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Affiliation(s)
- Heiner Latus
- Clinic for Congenital Heart Disease and Pediatric Cardiology, German Heart Center Munich, Munich, Germany
| | - Christian Meierhofer
- Clinic for Congenital Heart Disease and Pediatric Cardiology, German Heart Center Munich, Munich, Germany
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5
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Truong U, Meinel K, Haddad F, Koestenberger M, Carlsen J, Ivy D, Jone PN. Update on noninvasive imaging of right ventricle dysfunction in pulmonary hypertension. Cardiovasc Diagn Ther 2020; 10:1604-1624. [PMID: 33224776 DOI: 10.21037/cdt-20-272] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Pulmonary hypertension (PH) is a progressive disease affecting patients across the life span. The pathophysiology primarily involves the pulmonary vasculature and right ventricle (RV), but eventually affects the left ventricular (LV) function as well. Safe, accurate imaging modalities are critical for diagnosis, serial monitoring, and tailored therapy. While cardiac catheterization remains the conventional modality for establishing diagnosis and serial monitoring, noninvasive imaging has gained considerable momentum in providing accurate assessment of the entire RV-pulmonary axis. In this state-of-the-art review, we will discuss the most recent developments in echocardiography, magnetic resonance imaging, and computed tomography in PH evaluation from pediatric to adult population.
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Affiliation(s)
- Uyen Truong
- Division of Pediatric Cardiology, Children's Hospital of Richmond, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Katharina Meinel
- Division of Pediatric Cardiology, Medical University of Graz, Graz, Austria
| | - Francois Haddad
- Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California, USA
| | | | - Jørn Carlsen
- Department of Cardiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Dunbar Ivy
- Division of Pediatric Cardiology, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Pei-Ni Jone
- Division of Pediatric Cardiology, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, Colorado, USA
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6
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Wang L, Liu J, Zhong Y, Zhang M, Xiong J, Shen J, Tong Z, Xu Z. Medical Image-Based Hemodynamic Analyses in a Study of the Pulmonary Artery in Children With Pulmonary Hypertension Related to Congenital Heart Disease. Front Pediatr 2020; 8:521936. [PMID: 33344379 PMCID: PMC7738347 DOI: 10.3389/fped.2020.521936] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 10/13/2020] [Indexed: 12/21/2022] Open
Abstract
Objective: Pulmonary hypertension related to congenital heart disease (PH-CHD) is a devastating disease caused by hemodynamic disorders. Previous hemodynamic research in PH-CHD mainly focused on wall shear stress (WSS). However, energy loss (EL) is a vital parameter in evaluation of hemodynamic status. We investigated if EL of the pulmonary artery (PA) is a potential biomechanical marker for comprehensive assessment of PH-CHD. Materials and Methods: Ten PH-CHD patients and 10 age-matched controls were enrolled. Subject-specific 3-D PA models were reconstructed based on computed tomography. Transient flow, WSS, and EL in the PA were calculated using non-invasive computational fluid dynamics. The relationship between body surface area (BSA)-normalized EL ( E . ) and PA morphology and PA flow were analyzed. Results: Morphologic analysis indicated that the BSA-normalized main PA (MPA) diameter (DMPAnorm), MPA/aorta diameter ratio (DMPA/DAO), and MPA/(left PA + right PA) [DMPA/D(LPA+RPA)] diameter ratio were significantly larger in PH-CHD patients. Hemodynamic results showed that the velocity of the PA branches was higher in PH-CHD patients, in whom PA flow rate usually increased. WSS in the MPA was lower and E . was higher in PH-CHD patients. E . was positively correlated with DMPAnorm, DMPA/DAO, and DMPA/D(LPA+RPA) ratios and the flow rate in the PA. E . was a sensitive index for the diagnosis of PH-CHD. Conclusion: E . is a potential biomechanical marker for PH-CHD assessment. This hemodynamic parameter may lead to new directions for revealing the potential pathophysiologic mechanism of PH-CHD.
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Affiliation(s)
- Liping Wang
- Department of Thoracic and Cardiovascular Surgery, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jinlong Liu
- Department of Thoracic and Cardiovascular Surgery, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Pediatric Translational Medicine Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Engineering Research Center of Virtual Reality of Structural Heart Disease, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yumin Zhong
- Department of Radiology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Mingjie Zhang
- Department of Thoracic and Cardiovascular Surgery, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jiwen Xiong
- Department of Thoracic and Cardiovascular Surgery, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Juanya Shen
- Department of Thoracic and Cardiovascular Surgery, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Pediatric Translational Medicine Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Engineering Research Center of Virtual Reality of Structural Heart Disease, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhirong Tong
- Department of Thoracic and Cardiovascular Surgery, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Pediatric Translational Medicine Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Engineering Research Center of Virtual Reality of Structural Heart Disease, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhuoming Xu
- Department of Thoracic and Cardiovascular Surgery, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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7
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Friesen RM, Schäfer M, Ivy DD, Abman SH, Stenmark K, Browne LP, Barker AJ, Hunter KS, Truong U. Proximal pulmonary vascular stiffness as a prognostic factor in children with pulmonary arterial hypertension. Eur Heart J Cardiovasc Imaging 2019; 20:209-217. [PMID: 29788051 DOI: 10.1093/ehjci/jey069] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 04/23/2018] [Indexed: 11/12/2022] Open
Abstract
Aims Main pulmonary artery (MPA) stiffness and abnormal flow haemodynamics in pulmonary arterial hypertension (PAH) are strongly associated with elevated right ventricular (RV) afterload and associated with disease severity and poor clinical outcomes in adults with PAH. However, the long-term effects of MPA stiffness on RV function in children with PAH remain poorly understood. This study is the first comprehensive evaluation of MPA stiffness in children with PAH, delineating the mechanistic relationship between flow haemodynamics and MPA stiffness as well as the prognostic ability of these measures regarding clinical outcomes. Methods and results Fifty-six children diagnosed with PAH underwent baseline cardiac magnetic resonance (CMR) acquisition and were compared with 23 control subjects. MPA stiffness and wall shear stress (WSS) were evaluated using phase contrast CMR and were evaluated for prognostic potential along with standard RV volumetric and functional indices. Pulse wave velocity (PWV) was significantly increased (2.8 m/s vs. 1.4 m/s, P < 0.0001) and relative area change (RAC) was decreased (25% vs. 37%, P < 0.0001) in the PAH group, correlating with metrics of RV performance. Decreased WSS was associated with a decrease in RAC over time (r = 0.679, P < 0.001). For each unit increase in PWV, there was approximately a 3.2-fold increase in having a moderate clinical event. Conclusion MPA stiffness assessed by non-invasive CMR was increased in children with PAH and correlated with RV performance, suggesting that MPA stiffness is a major contribution to RV dysfunction. PWV is predictive of moderate clinical outcomes, and may be a useful prognostic marker of disease activity in children with PAH.
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Affiliation(s)
- Richard M Friesen
- Division of Cardiology, Heart Institute, Children's Hospital Colorado, University of Colorado Denver, Anschutz Medical Campus, 13123 E 16th Avenue, Aurora, CO, USA.,Department of Critical Care, Seattle Children's Hospital, University of Washington, 4800 Sand Point Way NE, Seattle, WA, USA
| | - Michal Schäfer
- Division of Cardiology, Heart Institute, Children's Hospital Colorado, University of Colorado Denver, Anschutz Medical Campus, 13123 E 16th Avenue, Aurora, CO, USA.,Department of Bioengineering, College of Engineering and Applied Sciences, University of Colorado Denver, Anschutz Medical Campus, 12705 E. Montview Ave, Aurora, CO, USA
| | - D Dunbar Ivy
- Division of Cardiology, Heart Institute, Children's Hospital Colorado, University of Colorado Denver, Anschutz Medical Campus, 13123 E 16th Avenue, Aurora, CO, USA
| | - Steven H Abman
- Division of Pulmonology, Breathing Institute, Children's Hospital Colorado, University of Colorado Denver, Anschutz Medical Campus, 13123 E 16th Avenue, Aurora, CO, USA
| | - Kurt Stenmark
- Developmental Lung Biology and Cardiovascular Pulmonary Research Laboratories, University of Colorado Denver, Anschutz Medical Campus, 12700 E 19th Ave, Box B131. Aurora, CO, USA
| | - Lorna P Browne
- Department of Radiology, Children's Hospital Colorado, University of Colorado Denver, Anschutz Medical Campus, 13123 E 16th Avenue, Aurora, CO, USA
| | - Alex J Barker
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N Michigan Ave, Suite 1600, Chicago, IL, USA
| | - Kendall S Hunter
- Division of Cardiology, Heart Institute, Children's Hospital Colorado, University of Colorado Denver, Anschutz Medical Campus, 13123 E 16th Avenue, Aurora, CO, USA.,Department of Bioengineering, College of Engineering and Applied Sciences, University of Colorado Denver, Anschutz Medical Campus, 12705 E. Montview Ave, Aurora, CO, USA
| | - Uyen Truong
- Division of Cardiology, Heart Institute, Children's Hospital Colorado, University of Colorado Denver, Anschutz Medical Campus, 13123 E 16th Avenue, Aurora, CO, USA
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8
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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] [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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9
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Evolution of hemodynamic forces in the pulmonary tree with progressively worsening pulmonary arterial hypertension in pediatric patients. Biomech Model Mechanobiol 2019; 18:779-796. [DOI: 10.1007/s10237-018-01114-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 12/24/2018] [Indexed: 01/26/2023]
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10
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Schäfer M, Wilson N, Ivy DD, Ing R, Abman S, Browne LP, Morgan G, Ross M, McLennan D, Barker AJ, Fonseca B, Di Maria M, Hunter KS, Truong U. Noninvasive wave intensity analysis predicts functional worsening in children with pulmonary arterial hypertension. Am J Physiol Heart Circ Physiol 2018; 315:H968-H977. [PMID: 30004811 DOI: 10.1152/ajpheart.00227.2018] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The purpose of the present study was to characterize pulmonary vascular stiffness using wave intensity analysis (WIA) in children with pulmonary arterial hypertension (PAH), compare the WIA indexes with catheterization- and MRI-derived hemodynamics, and assess the prognostic ability of WIA-derived biomarkers to predict the functional worsening. WIA was performed in children with PAH ( n = 40) and healthy control subjects ( n = 15) from phase-contrast MRI-derived flow and area waveforms in the main pulmonary artery (MPA). From comprehensive WIA spectra, we collected and compared with healthy control subjects forward compression waves (FCW), backward compression waves (BCW), forward decompression waves (FDW), and wave propagation speed ( c-MPA). There was no difference in the magnitude of FCW between PAH and control groups (88 vs. 108 mm5·s-1·ml-1, P = 0.239). The magnitude of BCW was increased in patients with PAH (32 vs. 5 mm5·s-1·ml-1, P < 0.001). There was no difference in magnitude of indexed FDW (32 vs. 28 mm5·s-1·ml-1, P = 0.856). c-MPA was increased in patients with PAH (3.2 vs. 1.6 m/s, P < 0.001). BCW and FCW correlated with mean pulmonary arterial pressure, right ventricular volumes, and ejection fraction. Elevated indexed BCW [heart rate (HR) = 2.91, confidence interval (CI): 1.18-7.55, P = 0.019], reduced indexed FDW (HR = 0.34, CI: 0.11-0.90, P = 0.030), and increased c-MPA (HR = 3.67, CI: 1.47-10.20, P = 0.004) were strongly associated with functional worsening of disease severity. Our results suggest that noninvasively derived biomarkers of pulmonary vascular resistance and stiffness may be helpful for determining prognosis and monitoring disease progression in children with PAH. NEW & NOTEWORTHY Wave intensity analysis (WIA) studies are lacking in children with pulmonary arterial hypertension (PAH) partially because WIA, which is necessary to assess vascular stiffness, requires an invasive pressure-derived waveform along with simultaneous flow measurements. We analyzed vascular stiffness using WIA in children with PAH who underwent phase-contrast MRI and observed significant differences in WIA indexes between patients with PAH and control subjects. Furthermore, WIA indexes were predictive of functional worsening and were associated with standard catheterization measures.
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Affiliation(s)
- Michal Schäfer
- Division of Cardiology, Heart Institute, Children's Hospital Colorado, University of Colorado Anschutz Medical Campus , Aurora, Colorado
| | - Neil Wilson
- Division of Cardiology, Heart Institute, Children's Hospital Colorado, University of Colorado Anschutz Medical Campus , Aurora, Colorado
| | - D Dunbar Ivy
- Division of Cardiology, Heart Institute, Children's Hospital Colorado, University of Colorado Anschutz Medical Campus , Aurora, Colorado
| | - Richard Ing
- Division of Pediatric Cardiac Anesthesiology, Children's Hospital Colorado, University of Colorado Anschutz Medical Campus , Aurora, Colorado
| | - Steven Abman
- Division of Pulmonology, Breathing Institute, University of Colorado Anschutz Medical Campus , Aurora, Colorado
| | - Lorna P Browne
- Department of Radiology, Children's Hospital Colorado, University of Colorado Anschutz Medical Campus , Aurora, Colorado
| | - Gareth Morgan
- Division of Cardiology, Heart Institute, Children's Hospital Colorado, University of Colorado Anschutz Medical Campus , Aurora, Colorado
| | - Michael Ross
- Division of Cardiology, Heart Institute, Children's Hospital Colorado, University of Colorado Anschutz Medical Campus , Aurora, Colorado
| | - Daniel McLennan
- Division of Cardiology, Heart Institute, Children's Hospital Colorado, University of Colorado Anschutz Medical Campus , Aurora, Colorado
| | - Alex J Barker
- Department of Radiology, Feinberg School of Medicine, Northwestern University , Chicago, Illinois
| | - Brian Fonseca
- Division of Cardiology, Heart Institute, Children's Hospital Colorado, University of Colorado Anschutz Medical Campus , Aurora, Colorado
| | - Michael Di Maria
- Division of Cardiology, Heart Institute, Children's Hospital Colorado, University of Colorado Anschutz Medical Campus , Aurora, Colorado
| | - Kendall S Hunter
- Division of Cardiology, Heart Institute, Children's Hospital Colorado, University of Colorado Anschutz Medical Campus , Aurora, Colorado
| | - Uyen Truong
- Division of Cardiology, Heart Institute, Children's Hospital Colorado, University of Colorado Anschutz Medical Campus , Aurora, Colorado
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11
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Measuring Flow Hemodynamic Indices and Oxygen Consumption in Children with Pulmonary Hypertension: A Comparison of Catheterization and Phase-Contrast MRI. Pediatr Cardiol 2018; 39:268-274. [PMID: 29043395 DOI: 10.1007/s00246-017-1751-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 10/07/2017] [Indexed: 12/31/2022]
Abstract
We sought to compare pulmonary flow hemodynamic indices obtained by Fick and thermodilution catheterization techniques with phase-contrast MRI (PC-MRI) in children with diverse etiologies of pulmonary arterial hypertension (PAH). Calculation of pulmonary flow ([Formula: see text]) using the Fick principle in most catheter laboratories relies on an estimate of oxygen consumption which may limit its reliability. Flow hemodynamic indices acquired from thirty patients with PAH who underwent successful same-day PC-MRI and catheterization were evaluated for absolute and percent bias. Comparison of [Formula: see text] between PC-MRI and Fick revealed poor agreement with an absolute bias of 0.96 ± 0.53 L/min/m2 and percent bias of 27.7 ± 19.6%. Same analysis between PC-MRI and thermodilution revealed better agreement as demonstrated by absolute bias 0.64 ± 0.47 L/min/m2 and percent bias 16.8 ± 12.3%. Retrospectively calculated [Formula: see text] from PC-MRI and LaFarge equations revealed poor agreement, with an absolute bias of 33.4 ± 21.6 mL/min/m2 and percent bias of 25.8 ± 12.6%. We found that Fick-derived flow hemodynamics dramatically differs from PC-MRI computed metrics in children with PAH. The non-invasive nature of PC-MRI and short acquisition time is ideal for pediatric flow evaluation and may offer a novel route of absolute flow and resistance assessment when combined with cardiac catheterization.
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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] [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] [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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Idiopathic Pulmonary Arterial Hypertension in Children: A Review. Pulm Ther 2017. [DOI: 10.1007/s41030-017-0035-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Ploegstra MJ, Brokelman JGM, Roos-Hesselink JW, Douwes JM, van Osch-Gevers LM, Hoendermis ES, van den Bosch AE, Witsenburg M, Bartelds B, Hillege HL, Berger RMF. Pulmonary arterial stiffness indices assessed by intravascular ultrasound in children with early pulmonary vascular disease: prediction of advanced disease and mortality during 20-year follow-up. Eur Heart J Cardiovasc Imaging 2017; 19:216-224. [DOI: 10.1093/ehjci/jex015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 01/27/2017] [Indexed: 01/26/2023] Open
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Schäfer M, Ivy DD, Abman SH, Barker AJ, Browne LP, Fonseca B, Kheyfets V, Hunter KS, Truong U. Apparent Aortic Stiffness in Children With Pulmonary Arterial Hypertension: Existence of Vascular Interdependency? Circ Cardiovasc Imaging 2017; 10:e005817. [PMID: 28193613 PMCID: PMC5314208 DOI: 10.1161/circimaging.116.005817] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 12/15/2016] [Indexed: 01/08/2023]
Abstract
BACKGROUND Left ventricular dysfunction, mediated by ventricular interdependence, has been associated with negative outcomes in children with pulmonary arterial hypertension (PAH). Considering the dilation of the pulmonary arteries as a paramount sign of PAH, we hypothesized that the ascending aorta will present signs of apparent stiffness in children with PAH and that this effect may be because of mechanical interaction with the dilated main pulmonary artery (MPA). METHODS AND RESULTS Forty-two children with PAH and 26 age- and size-matched controls underwent comprehensive cardiac magnetic resonance evaluation. Assessment of aortic stiffness was evaluated by measuring pulse wave velocity, aortic strain, and distensibility. Children with PAH had significantly increased pulse wave velocity in the ascending aorta (3.4 versus 2.3 m/s for PAH and controls, respectively; P=0.001) and reduced aortic strain (23% versus 29%; P<0.0001) and distensibility (0.47 versus 0.64%/mm Hg; P=0.02). Indexed MPA diameter correlated with pulse wave velocity (P=0.04) and with aortic strain (P=0.02). The ratio of MPA to aortic size correlated with pulse wave velocity (P=0.0098), strain (P=0.0099), and distensibility (P=0.015). Furthermore, aortic relative area change was associated with left ventricular ejection fraction (P=0.045) and ventricular-vascular coupling ratio (P=0.042). CONCLUSIONS Pediatric PAH patients have increased apparent ascending aortic stiffness, which was strongly associated with the degree of MPA distension. We speculate that distension of the MPA may play a major role in limiting full aortic expansion during systole, which modulates left ventricular performance and impacts systemic hemodynamics in pediatric PAH.
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Affiliation(s)
- Michal Schäfer
- From the Division of Cardiology, Heart Institute, Children's Hospital Colorado (M.S., D.D.I., B.F., K.S.H., U.T.), Department of Bioengineering, College of Engineering and Applied Sciences (M.S., D.D.I., V.K., K.S.H., U.T.), Division of Pulmonology, Breathing Institute, Children's Hospital Colorado (S.H.A.), and Department of Radiology, Children's Hospital Colorado (L.P.B.), University of Colorado Denver/Anschutz Medical Campus; and Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL (A.J.B.).
| | - D Dunbar Ivy
- From the Division of Cardiology, Heart Institute, Children's Hospital Colorado (M.S., D.D.I., B.F., K.S.H., U.T.), Department of Bioengineering, College of Engineering and Applied Sciences (M.S., D.D.I., V.K., K.S.H., U.T.), Division of Pulmonology, Breathing Institute, Children's Hospital Colorado (S.H.A.), and Department of Radiology, Children's Hospital Colorado (L.P.B.), University of Colorado Denver/Anschutz Medical Campus; and Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL (A.J.B.)
| | - Steven H Abman
- From the Division of Cardiology, Heart Institute, Children's Hospital Colorado (M.S., D.D.I., B.F., K.S.H., U.T.), Department of Bioengineering, College of Engineering and Applied Sciences (M.S., D.D.I., V.K., K.S.H., U.T.), Division of Pulmonology, Breathing Institute, Children's Hospital Colorado (S.H.A.), and Department of Radiology, Children's Hospital Colorado (L.P.B.), University of Colorado Denver/Anschutz Medical Campus; and Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL (A.J.B.)
| | - Alex J Barker
- From the Division of Cardiology, Heart Institute, Children's Hospital Colorado (M.S., D.D.I., B.F., K.S.H., U.T.), Department of Bioengineering, College of Engineering and Applied Sciences (M.S., D.D.I., V.K., K.S.H., U.T.), Division of Pulmonology, Breathing Institute, Children's Hospital Colorado (S.H.A.), and Department of Radiology, Children's Hospital Colorado (L.P.B.), University of Colorado Denver/Anschutz Medical Campus; and Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL (A.J.B.)
| | - Lorna P Browne
- From the Division of Cardiology, Heart Institute, Children's Hospital Colorado (M.S., D.D.I., B.F., K.S.H., U.T.), Department of Bioengineering, College of Engineering and Applied Sciences (M.S., D.D.I., V.K., K.S.H., U.T.), Division of Pulmonology, Breathing Institute, Children's Hospital Colorado (S.H.A.), and Department of Radiology, Children's Hospital Colorado (L.P.B.), University of Colorado Denver/Anschutz Medical Campus; and Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL (A.J.B.)
| | - Brian Fonseca
- From the Division of Cardiology, Heart Institute, Children's Hospital Colorado (M.S., D.D.I., B.F., K.S.H., U.T.), Department of Bioengineering, College of Engineering and Applied Sciences (M.S., D.D.I., V.K., K.S.H., U.T.), Division of Pulmonology, Breathing Institute, Children's Hospital Colorado (S.H.A.), and Department of Radiology, Children's Hospital Colorado (L.P.B.), University of Colorado Denver/Anschutz Medical Campus; and Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL (A.J.B.)
| | - Vitaly Kheyfets
- From the Division of Cardiology, Heart Institute, Children's Hospital Colorado (M.S., D.D.I., B.F., K.S.H., U.T.), Department of Bioengineering, College of Engineering and Applied Sciences (M.S., D.D.I., V.K., K.S.H., U.T.), Division of Pulmonology, Breathing Institute, Children's Hospital Colorado (S.H.A.), and Department of Radiology, Children's Hospital Colorado (L.P.B.), University of Colorado Denver/Anschutz Medical Campus; and Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL (A.J.B.)
| | - Kendall S Hunter
- From the Division of Cardiology, Heart Institute, Children's Hospital Colorado (M.S., D.D.I., B.F., K.S.H., U.T.), Department of Bioengineering, College of Engineering and Applied Sciences (M.S., D.D.I., V.K., K.S.H., U.T.), Division of Pulmonology, Breathing Institute, Children's Hospital Colorado (S.H.A.), and Department of Radiology, Children's Hospital Colorado (L.P.B.), University of Colorado Denver/Anschutz Medical Campus; and Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL (A.J.B.)
| | - Uyen Truong
- From the Division of Cardiology, Heart Institute, Children's Hospital Colorado (M.S., D.D.I., B.F., K.S.H., U.T.), Department of Bioengineering, College of Engineering and Applied Sciences (M.S., D.D.I., V.K., K.S.H., U.T.), Division of Pulmonology, Breathing Institute, Children's Hospital Colorado (S.H.A.), and Department of Radiology, Children's Hospital Colorado (L.P.B.), University of Colorado Denver/Anschutz Medical Campus; and Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL (A.J.B.)
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