1
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Darwish A, Papolla C, Rieu R, Kadem L. An Anatomically Shaped Mitral Valve for Hemodynamic Testing. Cardiovasc Eng Technol 2024; 15:374-381. [PMID: 38228812 DOI: 10.1007/s13239-024-00714-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 01/02/2024] [Indexed: 01/18/2024]
Abstract
In vitro modeling of the left heart relies on accurately replicating the physiological conditions of the native heart. The targeted physiological conditions include the complex fluid dynamics coming along with the opening and closing of the aortic and mitral valves. As the mitral valve possess a highly sophisticated apparatus, thence, accurately modeling it remained a missing piece in the perfect heart duplicator puzzle. In this study, we explore using a hydrogel-based mitral valve that offers a full representation of the mitral valve apparatus. The valve is tested using a custom-made mock circulatory loop to replicate the left heart. The flow analysis includes performing particle image velocimetry measurements in both left atrium and ventricle. The results showed the ability of the new mitral valve to replicate the real interventricular and atrial flow patterns during the whole cardiac cycle. Moreover, the investigated valve has a ventricular vortex formation time of 5.2, while the peak e- and a-wave ventricular velocities was 0.9 m/s and 0.4 m/s respectively.
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Affiliation(s)
- Ahmed Darwish
- Laboratory of Cardiovascular Fluid Dynamics, Concordia University, Montreal, QC, H3G 1M8, Canada.
- Mechanical Power Engineering Department, Assiut University, Assiut, 71515, Egypt.
| | - Chloé Papolla
- Laboratory of Cardiovascular Fluid Dynamics, Concordia University, Montreal, QC, H3G 1M8, Canada
- Aix-Marseille University, LBA UMR T24, Marseille, France
| | - Régis Rieu
- Aix-Marseille University, LBA UMR T24, Marseille, France
| | - Lyes Kadem
- Laboratory of Cardiovascular Fluid Dynamics, Concordia University, Montreal, QC, H3G 1M8, Canada
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2
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Yang K, Wu S, Samuel OW, Zhang H, Ghista DN, Yang D, Wong KKL. A Hybrid Approach for Cardiac Blood Flow Vortex Ring Identification Based on Optical Flow and Lagrangian Averaged Vorticity Deviation. Front Physiol 2021; 12:698405. [PMID: 34539430 PMCID: PMC8440940 DOI: 10.3389/fphys.2021.698405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 08/05/2021] [Indexed: 11/13/2022] Open
Abstract
Objective: The measurement of cardiac blood flow vortex characteristics can help to facilitate the analysis of blood flow dynamics that regulates heart function. However, the complexity of cardiac flow along with other physical limitations makes it difficult to adequately identify the dominant vortices in a heart chamber, which play a significant role in regulating the heart function. Although the existing vortex quantification methods can achieve this goal, there are still some shortcomings: such as low precision, and ignoring the center of the vortex without the description of vortex deformation processes. To address these problems, an optical flow Lagrangian averaged vorticity deviation (Optical flow-LAVD) method is proposed. Methodology: We examined the flow within the right atrium (RA) of the participants’ hearts, by using a single set of scans pertaining to a slice at two-chamber short-axis orientation. Toward adequate extraction of the vortex ring characteristics, a novel approach driven by the Lagrangian averaged vorticity deviation (LAVD) was implemented and applied to characterize the trajectory integral associated with vorticity deviation and the spatial mean of rings, by using phase-contrast magnetic resonance imaging (PC-MRI) datasets as a case study. To interpolate the time frames between every larger discrete frame and minimize the error caused by constructing a continuous velocity field for the integral process of LAVD, we implemented the optical flow as an interpolator and introduced the backward warping as an intermediate frame synthesis basis, which is then used to generate higher quality continuous velocity fields. Results: Our analytical study results showed that the proposed Optical flow-LAVD method can accurately identify vortex ring and continuous velocity fields, based on optical flow information, for yielding high reconstruction outcomes. Compared with the linear interpolation and phased-based frame interpolation methods, our proposed algorithm can generate more accurate synthesized PC-MRI. Conclusion: This study has developed a novel Optical flow-LAVD model to accurately identify cardiac vortex rings, and minimize the associated errors caused by the construction of a continuous velocity field. Our paper presents a superior vortex characteristics detection method that may potentially aid the understanding of medical experts on the dynamics of blood flow within the heart.
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Affiliation(s)
- Ke Yang
- Key Laboratory of Metallurgical Equipment and Control Technology, Ministry of Education, Wuhan University of Science and Technology, Wuhan, China.,Hubei Key Laboratory of Mechanical Transmission and Manufacturing Engineering, Wuhan University of Science and Technology, Wuhan, China
| | - Shiqian Wu
- School of Information Science and Engineering, Wuhan University of Science and Technology, Wuhan, China
| | - Oluwarotimi W Samuel
- Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Hui Zhang
- Ultrasound Department, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Dhanjoo N Ghista
- University 2020 Foundation, Inc., California City, CA, United States
| | - Di Yang
- Key Laboratory of Metallurgical Equipment and Control Technology, Ministry of Education, Wuhan University of Science and Technology, Wuhan, China.,Hubei Key Laboratory of Mechanical Transmission and Manufacturing Engineering, Wuhan University of Science and Technology, Wuhan, China
| | - Kelvin K L Wong
- Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
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3
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Katsushika S, Kodera S, Nakamoto M, Ninomiya K, Kakuda N, Shinohara H, Matsuoka R, Ieki H, Uehara M, Higashikuni Y, Nakanishi K, Nakao T, Takeda N, Fujiu K, Daimon M, Ando J, Akazawa H, Morita H, Komuro I. Deep Learning Algorithm to Detect Cardiac Sarcoidosis From Echocardiographic Movies. Circ J 2021; 86:87-95. [PMID: 34176867 DOI: 10.1253/circj.cj-21-0265] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Because the early diagnosis of subclinical cardiac sarcoidosis (CS) remains difficult, we developed a deep learning algorithm to distinguish CS patients from healthy subjects using echocardiographic movies.Methods and Results:Among the patients who underwent echocardiography from January 2015 to December 2019, we chose 151 echocardiographic movies from 50 CS patients and 151 from 149 healthy subjects. We trained two 3D convolutional neural networks (3D-CNN) to identify CS patients using a dataset of 212 echocardiographic movies with and without a transfer learning method (Pretrained algorithm and Non-pretrained algorithm). On an independent set of 41 echocardiographic movies, the area under the receiver-operating characteristic curve (AUC) of the Pretrained algorithm was greater than that of Non-pretrained algorithm (0.842, 95% confidence interval (CI): 0.722-0.962 vs. 0.724, 95% CI: 0.566-0.882, P=0.253). The AUC from the interpretation of the same set of 41 echocardiographic movies by 5 cardiologists was not significantly different from that of the Pretrained algorithm (0.855, 95% CI: 0.735-0.975 vs. 0.842, 95% CI: 0.722-0.962, P=0.885). A sensitivity map demonstrated that the Pretrained algorithm focused on the area of the mitral valve. CONCLUSIONS A 3D-CNN with a transfer learning method may be a promising tool for detecting CS using an echocardiographic movie.
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Affiliation(s)
- Susumu Katsushika
- Department of Cardiovascular Medicine, The University of Tokyo Hospital
| | - Satoshi Kodera
- Department of Cardiovascular Medicine, The University of Tokyo Hospital
| | | | - Kota Ninomiya
- Department of Cardiovascular Medicine, The University of Tokyo Hospital
| | - Nobutaka Kakuda
- Department of Cardiovascular Medicine, The University of Tokyo Hospital
| | - Hiroki Shinohara
- Department of Cardiovascular Medicine, The University of Tokyo Hospital
| | - Ryo Matsuoka
- Department of Cardiovascular Medicine, The University of Tokyo Hospital
| | - Hirotaka Ieki
- Department of Cardiovascular Medicine, The University of Tokyo Hospital
| | - Masae Uehara
- Department of Cardiovascular Medicine, The University of Tokyo Hospital
| | | | - Koki Nakanishi
- Department of Cardiovascular Medicine, The University of Tokyo Hospital
| | - Tomoko Nakao
- Department of Cardiovascular Medicine, The University of Tokyo Hospital.,Department of Clinical Laboratory, The University of Tokyo Hospital
| | - Norifumi Takeda
- Department of Cardiovascular Medicine, The University of Tokyo Hospital
| | - Katsuhito Fujiu
- Department of Cardiovascular Medicine, The University of Tokyo Hospital.,Department of Advanced Cardiology, The University of Tokyo
| | - Masao Daimon
- Department of Cardiovascular Medicine, The University of Tokyo Hospital.,Department of Clinical Laboratory, The University of Tokyo Hospital
| | - Jiro Ando
- Department of Cardiovascular Medicine, The University of Tokyo Hospital
| | - Hiroshi Akazawa
- Department of Cardiovascular Medicine, The University of Tokyo Hospital
| | - Hiroyuki Morita
- Department of Cardiovascular Medicine, The University of Tokyo Hospital
| | - Issei Komuro
- Department of Cardiovascular Medicine, The University of Tokyo Hospital
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4
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Xu F, Kenjereš S. Numerical simulations of flow patterns in the human left ventricle model with a novel dynamic mesh morphing approach based on radial basis function. Comput Biol Med 2021; 130:104184. [PMID: 33444850 DOI: 10.1016/j.compbiomed.2020.104184] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 12/15/2020] [Accepted: 12/15/2020] [Indexed: 10/22/2022]
Abstract
We present a new numerical simulation framework for prediction of flow patterns in the human left ventricle model. In this study, a radial basis function (RBF) mesh morphing method is developed and applied within the finite-volume computational fluid dynamics (CFD) approach. The numerical simulations are designed to closely mimic details of recent tomographic particle image velocimetry (TomoPIV) experiments. The numerically simulated dynamic motions of the left ventricle and tri-leaflet biological mitral valve are emulated through the RBF morphing method. The arbitrary Lagrangian-Eulerian (ALE) based CFD is performed with the RBF-defined deforming wall boundaries. The results obtained show a good agreement with experiments, confirming the reliability and accuracy of the developed simulation framework.
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Affiliation(s)
- Fei Xu
- Department of Chemical Engineering, Faculty of Applied Sciences, Delft University of Technology and J. M. Burgerscentrum Research School for Fluid Mechanics, Van der Maasweg 9, 2629 HZ, Delft, the Netherlands
| | - Saša Kenjereš
- Department of Chemical Engineering, Faculty of Applied Sciences, Delft University of Technology and J. M. Burgerscentrum Research School for Fluid Mechanics, Van der Maasweg 9, 2629 HZ, Delft, the Netherlands.
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5
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Diagnostic and prognostic significance of cardiovascular vortex formation. J Cardiol 2019; 74:403-411. [DOI: 10.1016/j.jjcc.2019.05.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Accepted: 05/07/2019] [Indexed: 12/16/2022]
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6
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Kulkarni A, Morisawa D, Gonzalez D, Kheradvar A. Age‐related changes in diastolic function in children: Echocardiographic association with vortex formation time. Echocardiography 2019; 36:1869-1875. [DOI: 10.1111/echo.14479] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Revised: 08/09/2019] [Accepted: 08/21/2019] [Indexed: 11/29/2022] Open
Affiliation(s)
- Aparna Kulkarni
- Department of Pediatric Cardiology Cohen Children’s Medical Center Zucker School of Medicine at Hofstra/Northwell New York NY USA
| | - Daisuke Morisawa
- Department of Biomedical Engineering University of California Irvine CA USA
- The Edwards Lifesciences Center for Advanced Cardiovascular Technology University of California Irvine CA USA
| | - Daisy Gonzalez
- Division of Pediatric Cardiology Children’s Hospital at Montefiore New York NY USA
| | - Arash Kheradvar
- Department of Biomedical Engineering University of California Irvine CA USA
- The Edwards Lifesciences Center for Advanced Cardiovascular Technology University of California Irvine CA USA
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7
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Ambrogio S, Walker A, Narracott A, Ferrari S, Verma P, Fenner J. A complex flow phantom for medical imaging: ring vortex phantom design and technical specification. J Med Eng Technol 2019; 43:190-201. [DOI: 10.1080/03091902.2019.1640309] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Simone Ambrogio
- Department of Infection, Immunity and Cardiovascular Disease, Medical Physics, Mathematical Modelling in Medicine Group, University of Sheffield, Sheffield, UK
- Insigneo Institute for In Silico Medicine, University of Sheffield, Sheffield, UK
- Leeds Test Objects Ltd, Boroughbridge, UK
| | | | - Andrew Narracott
- Department of Infection, Immunity and Cardiovascular Disease, Medical Physics, Mathematical Modelling in Medicine Group, University of Sheffield, Sheffield, UK
- Insigneo Institute for In Silico Medicine, University of Sheffield, Sheffield, UK
| | - Simone Ferrari
- Department of Infection, Immunity and Cardiovascular Disease, Medical Physics, Mathematical Modelling in Medicine Group, University of Sheffield, Sheffield, UK
- Insigneo Institute for In Silico Medicine, University of Sheffield, Sheffield, UK
| | - Prashant Verma
- Medical Imaging and Medical Physics, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK
| | - John Fenner
- Department of Infection, Immunity and Cardiovascular Disease, Medical Physics, Mathematical Modelling in Medicine Group, University of Sheffield, Sheffield, UK
- Insigneo Institute for In Silico Medicine, University of Sheffield, Sheffield, UK
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8
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Rasooli R, Pekkan K. Heart valve inspired and multi‐stream aortic cannula: Novel designs for cardiopulmonary bypass improvement in neonates. Artif Organs 2019; 43:E233-E248. [DOI: 10.1111/aor.13462] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 03/14/2019] [Accepted: 03/21/2019] [Indexed: 12/14/2022]
Affiliation(s)
- Reza Rasooli
- Department of Mechanical Engineering Koç University Sarıyer, Istanbul Turkey
| | - Kerem Pekkan
- Department of Mechanical Engineering Koç University Sarıyer, Istanbul Turkey
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9
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Morisawa D, Falahatpisheh A, Avenatti E, Little SH, Kheradvar A. Intraventricular Vortex Interaction between Transmitral Flow and Paravalvular Leak. Sci Rep 2018; 8:15657. [PMID: 30353062 PMCID: PMC6199255 DOI: 10.1038/s41598-018-33648-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 09/21/2018] [Indexed: 01/19/2023] Open
Abstract
Paravalvular leak (PVL) is a complication of transcatheter aortic valve replacement. Despite its marked clinical impact, no previous study has reported how PVL affects the intraventricular fluid dynamics. This study aims to delineate vortex interaction between PVL and transmitral flow and the influence of PVL orifice location on intraventricular fluid dynamics using Echocardiographic Particle Image Velocimetry. Three different conditions of no PVL, anterior PVL and posterior PVL were experimentally studied and clinically compared. Circulation, impulse, kinetic energy (KE) and change in KE (ΔKE) were calculated. As well, vortex formation analyses and streamline description were performed to study vortex interactions. The anterior PVL jet streamed into the LV and interfered with the transmitral flow. Posterior PVL jet formed a large clockwise vortex and collided with transmitral flow, which resulted in flow disturbance. Compared to no PVL condition, average circulation, impulse, KE and ΔKE increased in presence of PVL. In conclusion, we found that PVL jets lead to abnormal vortex formation that interfere with natural advancement of transmitral flow, and negatively affect the LV fluid dynamics parameters. PVL orifice location strongly affects the intraventricular vortex formation, and posterior PVL may have more negative effects compared to anterior PVL.
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Affiliation(s)
- Daisuke Morisawa
- The Edwards Lifesciences Center for Advanced Cardiovascular Technology, University of California, Irvine, CA, USA
| | - Ahmad Falahatpisheh
- The Edwards Lifesciences Center for Advanced Cardiovascular Technology, University of California, Irvine, CA, USA
| | - Eleonora Avenatti
- The Houston Methodist DeBakey Heart and Vascular Center, Houston, TX, USA
| | - Stephen H Little
- The Houston Methodist DeBakey Heart and Vascular Center, Houston, TX, USA
| | - Arash Kheradvar
- The Edwards Lifesciences Center for Advanced Cardiovascular Technology, University of California, Irvine, CA, USA.
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10
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Govindarajan V, Mousel J, Udaykumar HS, Vigmostad SC, McPherson DD, Kim H, Chandran KB. Synergy between Diastolic Mitral Valve Function and Left Ventricular Flow Aids in Valve Closure and Blood Transport during Systole. Sci Rep 2018; 8:6187. [PMID: 29670148 PMCID: PMC5906696 DOI: 10.1038/s41598-018-24469-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 03/27/2018] [Indexed: 11/30/2022] Open
Abstract
Highly resolved three-dimensional (3D) fluid structure interaction (FSI) simulation using patient-specific echocardiographic data can be a powerful tool for accurately and thoroughly elucidating the biomechanics of mitral valve (MV) function and left ventricular (LV) fluid dynamics. We developed and validated a strongly coupled FSI algorithm to fully characterize the LV flow field during diastolic MV opening under physiologic conditions. Our model revealed that distinct MV deformation and LV flow patterns developed during different diastolic stages. A vortex ring that strongly depended on MV deformation formed during early diastole. At peak E wave, the MV fully opened, with a local Reynolds number of ~5500, indicating that the flow was in the laminar-turbulent transitional regime. Our results showed that during diastasis, the vortex structures caused the MV leaflets to converge, thus increasing mitral jet’s velocity. The vortex ring became asymmetrical, with the vortex structures on the anterior side being larger than on the posterior side. During the late diastolic stages, the flow structures advected toward the LV outflow tract, enhancing fluid transport to the aorta. This 3D-FSI study demonstrated the importance of leaflet dynamics, their effect on the vortex ring, and their influence on MV function and fluid transport within the LV during diastole.
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Affiliation(s)
- Vijay Govindarajan
- Department of Biomedical Engineering, The University of Iowa, Iowa City, IA, USA.,Division of Cardiovascular Medicine, Department of Internal Medicine, The University of Texas McGovern Medical School, Houston, TX, USA
| | - John Mousel
- Department of Biomedical Engineering, The University of Iowa, Iowa City, IA, USA
| | - H S Udaykumar
- Department of Biomedical Engineering, The University of Iowa, Iowa City, IA, USA
| | - Sarah C Vigmostad
- Department of Biomedical Engineering, The University of Iowa, Iowa City, IA, USA
| | - David D McPherson
- Division of Cardiovascular Medicine, Department of Internal Medicine, The University of Texas McGovern Medical School, Houston, TX, USA
| | - Hyunggun Kim
- Division of Cardiovascular Medicine, Department of Internal Medicine, The University of Texas McGovern Medical School, Houston, TX, USA. .,Department of Biomechatronic Engineering, Sungkyunkwan University, Suwon, Gyeonggi, Korea.
| | - Krishnan B Chandran
- Department of Biomedical Engineering, The University of Iowa, Iowa City, IA, USA.
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11
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Pagel PS, Dye L, Boettcher BT, Freed JK. Advanced Age Attenuates Left Ventricular Filling Efficiency Quantified Using Vortex Formation Time: A Study of Octogenarians With Normal Left Ventricular Systolic Function Undergoing Coronary Artery Surgery. J Cardiothorac Vasc Anesth 2018. [PMID: 29525195 DOI: 10.1053/j.jvca.2018.02.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Blood flow across the mitral valve during early left ventricular (LV) filling produces a 3-dimensional rotational fluid body, known as a vortex ring, that enhances LV filling efficiency. Diastolic dysfunction is common in elderly patients, but the influence of advanced age on vortex formation is unknown. The authors tested the hypothesis that advanced age is associated with a reduction in LV filling efficiency quantified using vortex formation time (VFT) in octogenarians undergoing coronary artery bypass graft (CABG) surgery. DESIGN Observational study. SETTING Veterans Affairs medical center. PARTICIPANTS After institutional review board approval, octogenarians (n = 7; 82 ± 2 year [mean ± standard deviation]; ejection fraction 56% ± 7%) without valve disease or atrial arrhythmias undergoing CABG were compared with a younger cohort (n = 7; 55 ± 6 year; ejection fraction 57% ± 7%) who were undergoing coronary revascularization. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS All patients were monitored using radial and pulmonary arterial catheters and transesophageal echocardiography. Peak early LV filling (E) and atrial systole (A) blood flow velocities and their corresponding velocity-time integrals were obtained using pulse-wave Doppler echocardiography to determine E/A, atrial filling fraction (β), and E wave deceleration time. Pulse-wave Doppler also was used to measure pulmonary venous blood flow during systole and diastole. Mitral valve diameter (D) was calculated as the average of major and minor axis lengths obtained in the midesophageal LV bicommissural and long-axis transesophageal echocardiography imaging planes, respectively. VFT was calculated as 4 × (1 - β) × SV/(πD3), where SV is the stroke volume measured using thermodilution. Systemic and pulmonary hemodynamics, LV diastolic function, and VFT were determined during steady-state conditions 30 minutes before cardiopulmonary bypass. A delayed relaxation pattern of LV filling (E/A 0.81 ± 0.16 v 1.29 ± 0.19, p = 0.00015; β 0.44 ± 0.05 v 0.35 ± 0.03, p = 0.0008; E wave deceleration time 294 ± 58 v 166 ± 28 ms, p < 0.0001; ratio of peak pulmonary venous systolic and diastolic blood flow velocity 1.42 ± 0.23 v 1.14 ± 0.20, p = 0.0255) was observed in octogenarians compared with younger patients. Mitral valve diameter was similar between groups (2.7 ± 0.2 and 2.6 ± 0.2 cm, respectively, in octogenarians v younger patients, p = 0.299). VFT was reduced in octogenarians compared with younger patients (3.0 ± 0.9 v 4.5 ± 1.2; p = 0.0171). An inverse correlation between age and VFT was shown using linear regression analysis (VFT = -0.0627 × age + 8.24; r2 = 0.408; p = 0.0139). CONCLUSION The results indicate that LV filling efficiency quantified using VFT is reduced in octogenarians compared with younger patients undergoing coronary artery bypass grafting.
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Affiliation(s)
- Paul S Pagel
- Anesthesia Service, Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, WI.
| | - Lonnie Dye
- Anesthesia Service, Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, WI
| | - Brent T Boettcher
- Anesthesia Service, Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, WI
| | - Julie K Freed
- Anesthesia Service, Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, WI
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12
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13
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Goya S, Wada T, Shimada K, Hirao D, Tanaka R. The relationship between systolic vector flow mapping parameters and left ventricular cardiac function in healthy dogs. Heart Vessels 2017; 33:549-560. [PMID: 29230570 DOI: 10.1007/s00380-017-1093-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 12/01/2017] [Indexed: 11/24/2022]
Abstract
Vector flow mapping (VFM) is a novel echocardiographic technology that shows blood flow vectors and vortexes, enabled the hydrokinetic evaluation of hemodynamics within the left ventricle. VFM provides several unique parameters: circulation, vorticity, vortex area, and energy loss. The present study aims to reveal a relationship between VFM parameters and cardiac function. Five healthy Beagle dogs were anesthetized and administered with dobutamine (0, 2, 4, 8, 12 µg/kg/min). Pressure-volume diagrams were acquired to assess cardiac function using pressure-volume conductance catheter. Systolic maximum circulation, vorticity, vortex area, and energy loss were measured using VFM. The systolic maximum circulation, systolic vorticity, systolic vortex area, and systolic energy loss were increased by dobutamine administration. There was a strongly significant correlation between the systolic maximum circulation and ejection fraction (r = 0.76), maximal positive left ventricular (LV) pressure derivatives (dP/dt max) (r = 0.80), and end-systolic LV elastance (r = 0.73). Systolic vorticity and systolic vortex area were strongly correlated with ejection fraction (r = 0.76, 0.68) and dP/dt max (r = 0.76, 0.69), and end-systolic LV elastance (r = 0.62, 0.74), respectively. Systolic energy loss was strongly correlated with dP/dt max (r = 0.78), systolic maximum circulation (r = 0.81), and systolic vorticity (r = 0.82). The present study revealed that systolic VFM parameters are associated with the LV contractility. Furthermore, systolic energy loss was susceptible to the systolic vortex parameters such as systolic vorticity and systolic maximum circulation. Systolic VFM parameters are new hydrokinetic indices reflecting LV contractility.
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Affiliation(s)
- Seijirow Goya
- Department of Veterinary Surgery, Faculty of Veterinary Medicine, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo, 183-8509, Japan.
| | - Tomoki Wada
- Department of Veterinary Surgery, Faculty of Veterinary Medicine, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo, 183-8509, Japan
| | - Kazumi Shimada
- Department of Veterinary Surgery, Faculty of Veterinary Medicine, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo, 183-8509, Japan
| | - Daiki Hirao
- Department of Veterinary Surgery, Faculty of Veterinary Medicine, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo, 183-8509, Japan
| | - Ryou Tanaka
- Department of Veterinary Surgery, Faculty of Veterinary Medicine, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo, 183-8509, Japan
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14
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Tang C, Zhu Y, Zhang J, Niu C, Liu D, Liao Y, Zhu L, Peng Q. Analysis of left ventricular fluid dynamics in dilated cardiomyopathy by echocardiographic particle image velocimetry. Echocardiography 2017; 35:56-63. [PMID: 29082600 DOI: 10.1111/echo.13732] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Affiliation(s)
- Chouchou Tang
- Imaging and Nuclear Medicine; Ultrasound Department; the Second Xiangya Hospital of Central South University; Changsha Hunan Province China
- Imaging and Nuclear Medicine, Ultrasound Room; Infection Department; the Second Xiangya Hospital of Central South University; Changsha Hunan Province China
| | - Yizhong Zhu
- Internal Medicine; First Affiliated Hospital of Sun Yat-sen University; Guangzhou Guangdong Province China
| | - Jing Zhang
- Imaging and Nuclear Medicine; Ultrasound Department; the Second Xiangya Hospital of Central South University; Changsha Hunan Province China
| | - Chengcheng Niu
- Imaging and Nuclear Medicine; Ultrasound Department; the Second Xiangya Hospital of Central South University; Changsha Hunan Province China
| | - Dan Liu
- Imaging and Nuclear Medicine; Ultrasound Department; the Second Xiangya Hospital of Central South University; Changsha Hunan Province China
| | - Yacong Liao
- Imaging and Nuclear Medicine; Ultrasound Department; the Second Xiangya Hospital of Central South University; Changsha Hunan Province China
| | - Lijun Zhu
- Imaging and Nuclear Medicine; the First Affiliated Hospital of Southern Medical University; Guangzhou Guangdong Province China
| | - Qinghai Peng
- Imaging and Nuclear Medicine; Ultrasound Department; the Second Xiangya Hospital of Central South University; Changsha Hunan Province China
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15
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Kheradvar A. On the accuracy of intracardiac flow velocimetry methods. J Echocardiogr 2017; 15:67-69. [DOI: 10.1007/s12574-017-0332-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 01/09/2017] [Indexed: 12/11/2022]
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Falahatpisheh A, Morisawa D, Toosky TT, Kheradvar A. A calcified polymeric valve for valve-in-valve applications. J Biomech 2017; 50:77-82. [PMID: 27887725 DOI: 10.1016/j.jbiomech.2016.11.027] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 11/05/2016] [Indexed: 11/16/2022]
Abstract
The prevalence of aortic valve stenosis (AS) is increasing in the aging society. More recently, novel treatments and devices for AS, especially transcatheter aortic valve replacement (TAVR) have significantly changed the therapeutic approach to this disease. Research and development related to TAVR require testing these devices in the calcified heart valves that closely mimic a native calcific valve. However, no animal model of AS has yet been available. Alternatively, animals with normal aortic valve that are currently used for TAVR experiments do not closely replicate the aortic valve pathology required for proper testing of these devices. To solve this limitation, for the first time, we developed a novel polymeric valve whose leaflets possess calcium hydroxyapatite inclusions immersed in them. This study reports the characteristics and feasibility of these valves. Two types of the polymeric valve, i.e., moderate and severe calcified AS models were developed and tested by deploying a transcatheter valve in those and measuring the related hemodynamics. The valves were tested in a heart flow simulator, and were studied using echocardiography. Our results showed high echogenicity of the polymeric valve, that was correlated to the severity of the calcification. Aortic valve area of the polymeric valves was measured, and the severity of stenosis was defined according to the clinical guidelines. Accordingly, we showed that these novel polymeric valves closely mimic AS, and can be a desired cost-saving solution for testing the performance of the transcatheter aortic valve systems in vitro.
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Affiliation(s)
- Ahmad Falahatpisheh
- The Edwards Lifesciences Center for Advanced Cardiovascular Technology, University of California Irvine, Irvine, CA 92697, USA
| | - Daisuke Morisawa
- The Edwards Lifesciences Center for Advanced Cardiovascular Technology, University of California Irvine, Irvine, CA 92697, USA
| | - Taraz T Toosky
- Toosky Engineering Models Inc., 2650 Walnut Ave # N, Tustin, CA 92780, USA
| | - Arash Kheradvar
- The Edwards Lifesciences Center for Advanced Cardiovascular Technology, University of California Irvine, Irvine, CA 92697, USA.
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Okafor IU, Santhanakrishnan A, Raghav VS, Yoganathan AP. Role of Mitral Annulus Diastolic Geometry on Intraventricular Filling Dynamics. J Biomech Eng 2016; 137:121007. [PMID: 26502376 DOI: 10.1115/1.4031838] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Indexed: 11/08/2022]
Abstract
The mitral valve (MV) is a bileaflet valve positioned between the left atrium and ventricle of the heart. The annulus of the MV has been observed to undergo geometric changes during the cardiac cycle, transforming from a saddle D-shape during systole to a flat (and less eccentric) D-shape during diastole. Prosthetic MV devices, including heart valves and annuloplasty rings, are designed based on these two configurations, with the circular design of some prosthetic heart valves (PHVs) being an approximation of the less eccentric, flat D-shape. Characterizing the effects of these geometrical variations on the filling efficiency of the left ventricle (LV) is required to understand why the flat D-shaped annulus is observed in the native MV during diastole in addition to optimizing the design of prosthetic devices. We hypothesize that the D-shaped annulus reduces energy loss during ventricular filling. An experimental left heart simulator (LHS) consisting of a flexible-walled LV physical model was used to characterize the filling efficiency of the two mitral annular geometries. The strength of the dominant vortical structure formed and the energy dissipation rate (EDR) of the measured fields, during the diastolic period of the cardiac cycle, were used as metrics to quantify the filling efficiency. Our results indicated that the O-shaped annulus generates a stronger (25% relative to the D-shaped annulus) vortical structure than that of the D-shaped annulus. It was also found that the O-shaped annulus resulted in higher EDR values throughout the diastolic period of the cardiac cycle. The results support the hypothesis that a D-shaped mitral annulus reduces dissipative energy losses in ventricular filling during diastole and in turn suggests that a symmetric stent design does not provide lower filling efficiency than an equivalent asymmetric design.
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Pagel PS, Boettcher BT, De Vry DJ, Freed JK, Iqbal Z. Moderate Aortic Valvular Insufficiency Invalidates Vortex Formation Time as an Index of Left Ventricular Filling Efficiency in Patients With Severe Degenerative Calcific Aortic Stenosis Undergoing Aortic Valve Replacement. J Cardiothorac Vasc Anesth 2016; 30:1260-5. [PMID: 27474333 DOI: 10.1053/j.jvca.2016.03.144] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Transmitral blood flow produces a vortex ring (quantified using vortex formation time [VFT]) that enhances the efficiency of left ventricular (LV) filling. VFT is attenuated in LV hypertrophy resulting from aortic valve stenosis (AS) versus normal LV geometry. Many patients with AS also have aortic insufficiency (AI). The authors tested the hypothesis that moderate AI falsely elevates VFT by partially inhibiting mitral leaflet opening in patients with AS. DESIGN Observational study. SETTING Veterans Affairs medical center. PARTICIPANTS Patients with AS in the presence or absence of moderate AI (n = 8 per group) undergoing aortic valve replacement (AVR) were studied after institutional review board approval. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Under general anesthesia, peak early LV filling (E) and atrial systole (A) blood flow velocities and their corresponding velocity-time integrals were obtained using pulse-wave Doppler transesophageal echocardiography (TEE) to determine E/A and atrial filling fraction (beta). Mitral valve diameter (D) was calculated as the average of major and minor axis lengths obtained in the midesophageal bicommissural (transcommissural anterior-lateral-posterior medial) and LV long-axis (anterior-posterior) TEE imaging planes, respectively. VFT was calculated as 4·(1-beta)·SV/πD(3), where SV = stroke volume measured using thermodilution. Hemodynamics, diastolic function, and VFT were determined during steady-state conditions before cardiopulmonary bypass. The severity of AS (mean and peak pressure gradients, peak transvalvular jet velocity, aortic valve area) and diastolic function (E/A, beta) were similar between groups. Moderate centrally directed AI was present in 8 patients with AS (ratio of regurgitant jet width to LV outflow tract diameter of 36±6%). Pulse pressure and mean pulmonary artery pressure were elevated in patients with versus without AI, but no other differences in hemodynamics were observed. Mitral valve minor and major axis lengths, diameter, and area were reduced in the presence versus the absence of AI. VFT was increased significantly (5.7±1.7 v 3.2±0.6; p = 0.00108) in patients with AS and AI compared with AS alone. CONCLUSION Moderate AI falsely elevates VFT in patients with severe AS undergoing AVR by partially inhibiting mitral valve opening. VFT may be an unreliable index of LV filling efficiency with competitive diastolic flow into the LV.
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Affiliation(s)
- Paul S Pagel
- Anesthesia Service, Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, WI.
| | - Brent T Boettcher
- Anesthesia Service, Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, WI
| | - Derek J De Vry
- Anesthesia Service, Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, WI
| | - Julie K Freed
- Anesthesia Service, Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, WI
| | - Zafar Iqbal
- Anesthesia Service, Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, WI
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In Vitro 2D PIV Measurements and Related Aperture Areas of Tricuspid Bioprosthetic Mitral Valves at the beginning of Diastole. Int J Artif Organs 2016; 39:253-7. [DOI: 10.5301/ijao.5000494] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/11/2016] [Indexed: 11/20/2022]
Abstract
Purpose Besides ventricular parameters, the design and angular orientation of a prosthetic heart valve induce a specific flow field. The aim of this study was to know the inflow characteristics of a left ventricular model (LVM), investigating the behavior of tricuspid bioprosthetic mitral valves in terms of velocity profiles and related valve aperture areas at the beginning of diastole, under different conditions. Methods 3 heart rates (HRs) were established in the LVM and each mitral bioprosthesis (27 and 31 mm diameter) was installed in 2 orientations, rotated by 180°. For each experimental setup, 2-dimensional particle image velocimetry (2D PIV) measurements and simultaneous mitral valve (MV) area detection were obtained from 50 samples. Results The results from the velocity profiles immediately downstream of mitral bioprostheses showed the influence of valve orientation for moderate HRs, although for a similar magnitude of mean velocity vectors. The geometries of MV open areas for each HR were similar regardless of valve orientation, except for the 27-mm valve at 90 beats per minute (bpm), and for the 31-mm valve at 60 bpm. Moreover, for each HR, similar percentages of valve open area were obtained regardless of MV nominal diameters. Conclusions In conclusion, the experimental setup for the 2D PIV measurements synchronized with the MV area detection was a useful tool for knowing the inflow characteristics of the LVM.
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Chnafa C, Mendez S, Nicoud F. Image-Based Simulations Show Important Flow Fluctuations in a Normal Left Ventricle: What Could be the Implications? Ann Biomed Eng 2016; 44:3346-3358. [DOI: 10.1007/s10439-016-1614-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 04/06/2016] [Indexed: 10/22/2022]
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21
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Irizarry Pagán EE, Vargas PE, López-Candales A. The clinical dilemma of heart failure with preserved ejection fraction: an update on pathophysiology and management for physicians. Postgrad Med J 2016; 92:346-55. [DOI: 10.1136/postgradmedj-2015-133859] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 02/11/2016] [Indexed: 12/20/2022]
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Vector Flow Mapping in Mitral Valve Disease: a Novel Method for the Assessment of Flow Mechanics and Their Potential Implications for Mitral Valve Repair. CURRENT CARDIOVASCULAR IMAGING REPORTS 2015. [DOI: 10.1007/s12410-015-9358-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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23
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Okafor IU, Santhanakrishnan A, Chaffins BD, Mirabella L, Oshinski JN, Yoganathan AP. Cardiovascular magnetic resonance compatible physical model of the left ventricle for multi-modality characterization of wall motion and hemodynamics. J Cardiovasc Magn Reson 2015; 17:51. [PMID: 26112155 PMCID: PMC4482204 DOI: 10.1186/s12968-015-0154-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Accepted: 06/10/2015] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND The development of clinically applicable fluid-structure interaction (FSI) models of the left heart is inherently challenging when using in vivo cardiovascular magnetic resonance (CMR) data for validation, due to the lack of a well-controlled system where detailed measurements of the ventricular wall motion and flow field are available a priori. The purpose of this study was to (a) develop a clinically relevant, CMR-compatible left heart physical model; and (b) compare the left ventricular (LV) volume reconstructions and hemodynamic data obtained using CMR to laboratory-based experimental modalities. METHODS The LV was constructed from optically clear flexible silicone rubber. The geometry was based off a healthy patient's LV geometry during peak systole. The LV phantom was attached to a left heart simulator consisting of an aorta, atrium, and systemic resistance and compliance elements. Experiments were conducted for heart rate of 70 bpm. Wall motion measurements were obtained using high speed stereo-photogrammetry (SP) and cine-CMR, while flow field measurements were obtained using digital particle image velocimetry (DPIV) and phase-contrast magnetic resonance (PC-CMR). RESULTS The model reproduced physiologically accurate hemodynamics (aortic pressure = 120/80 mmHg; cardiac output = 3.5 L/min). DPIV and PC-CMR results of the center plane flow within the ventricle matched, both qualitatively and quantitatively, with flow from the atrium into the LV having a velocity of about 1.15 m/s for both modalities. The normalized LV volume through the cardiac cycle computed from CMR data matched closely to that from SP. The mean difference between CMR and SP was 5.5 ± 3.7%. CONCLUSIONS The model presented here can thus be used for the purposes of: (a) acquiring CMR data for validation of FSI simulations, (b) determining accuracy of cine-CMR reconstruction methods, and
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Affiliation(s)
- Ikechukwu U Okafor
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA.
| | - Arvind Santhanakrishnan
- School of Mechanical & Aerospace Engineering, Oklahoma State University, Stillwater, OK, USA.
| | - Brandon D Chaffins
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA.
| | - Lucia Mirabella
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA.
| | - John N Oshinski
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA.
- Department of Radiology and Imaging Sciences, School of Medicine, Emory University, Atlanta, GA, USA.
| | - Ajit P Yoganathan
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA.
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA.
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A Reconstruction Method of Blood Flow Velocity in Left Ventricle Using Color Flow Ultrasound. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2015; 2015:108274. [PMID: 26078773 PMCID: PMC4452383 DOI: 10.1155/2015/108274] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 12/25/2014] [Indexed: 11/17/2022]
Abstract
Vortex flow imaging is a relatively new medical imaging method for the dynamic visualization of intracardiac blood flow, a potentially useful index of cardiac dysfunction. A reconstruction method is proposed here to quantify the distribution of blood flow velocity fields inside the left ventricle from color flow images compiled from ultrasound measurements. In this paper, a 2D incompressible Navier-Stokes equation with a mass source term is proposed to utilize the measurable color flow ultrasound data in a plane along with the moving boundary condition. The proposed model reflects out-of-plane blood flows on the imaging plane through the mass source term. The boundary conditions to solve the system of equations are derived from the dimensions of the ventricle extracted from 2D echocardiography data. The performance of the proposed method is evaluated numerically using synthetic flow data acquired from simulating left ventricle flows. The numerical simulations show the feasibility and potential usefulness of the proposed method of reconstructing the intracardiac flow fields. Of particular note is the finding that the mass source term in the proposed model improves the reconstruction performance.
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25
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Su B, Kabinejadian F, Phang HQ, Kumar GP, Cui F, Kim S, Tan RS, Hon JKF, Allen JC, Leo HL, Zhong L. Numerical Modeling of Intraventricular Flow during Diastole after Implantation of BMHV. PLoS One 2015; 10:e0126315. [PMID: 25961285 PMCID: PMC4427484 DOI: 10.1371/journal.pone.0126315] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 03/31/2015] [Indexed: 12/20/2022] Open
Abstract
This work presents a numerical simulation of intraventricular flow after the implantation of a bileaflet mechanical heart valve at the mitral position. The left ventricle was simplified conceptually as a truncated prolate spheroid and its motion was prescribed based on that of a healthy subject. The rigid leaflet rotation was driven by the transmitral flow and hence the leaflet dynamics were solved using fluid-structure interaction approach. The simulation results showed that the bileaflet mechanical heart valve at the mitral position behaved similarly to that at the aortic position. Sudden area expansion near the aortic root initiated a clockwise anterior vortex, and the continuous injection of flow through the orifice resulted in further growth of the anterior vortex during diastole, which dominated the intraventricular flow. This flow feature is beneficial to preserving the flow momentum and redirecting the blood flow towards the aortic valve. To the best of our knowledge, this is the first attempt to numerically model intraventricular flow with the mechanical heart valve incorporated at the mitral position using a fluid-structure interaction approach. This study facilitates future patient-specific studies.
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Affiliation(s)
- Boyang Su
- National Heart Research Institute of Singapore, National Heart Centre Singapore, Singapore, Singapore
| | - Foad Kabinejadian
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore
| | - Hui Qun Phang
- Department of Surgery, National University of Singapore, Singapore, Singapore
| | | | - Fangsen Cui
- Institute of High Performance Computing, ASTAR, Singapore, Singapore
| | - Sangho Kim
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore
| | - Ru San Tan
- National Heart Research Institute of Singapore, National Heart Centre Singapore, Singapore, Singapore
| | - Jimmy Kim Fatt Hon
- Department of Surgery, National University of Singapore, Singapore, Singapore
| | | | - Hwa Liang Leo
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore
| | - Liang Zhong
- National Heart Research Institute of Singapore, National Heart Centre Singapore, Singapore, Singapore
- Duke-NUS Graduate Medical School, Singapore, Singapore
- * E-mail:
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26
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Effect of the Mitral Valve’s Anterior Leaflet on Axisymmetry of Transmitral Vortex Ring. Ann Biomed Eng 2015; 43:2349-60. [DOI: 10.1007/s10439-015-1302-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 03/13/2015] [Indexed: 10/23/2022]
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27
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Gao H, Bijnens N, Coisne D, Lugiez M, Rutten M, D'hooge J. 2-D left ventricular flow estimation by combining speckle tracking with Navier-Stokes-based regularization: an in silico, in vitro and in vivo study. ULTRASOUND IN MEDICINE & BIOLOGY 2015; 41:99-113. [PMID: 25438850 DOI: 10.1016/j.ultrasmedbio.2014.08.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 08/19/2014] [Accepted: 08/24/2014] [Indexed: 06/04/2023]
Abstract
Despite the availability of multiple ultrasound approaches to left ventricular (LV) flow characterization in two dimensions, this technique remains in its childhood and further developments seem warranted. This article describes a new methodology for tracking the 2-D LV flow field based on ultrasound data. Hereto, a standard speckle tracking algorithm was modified by using a dynamic kernel embedding Navier-Stokes-based regularization in an iterative manner. The performance of the proposed approach was first quantified in synthetic ultrasound data based on a computational fluid dynamics model of LV flow. Next, an experimental flow phantom setup mimicking the normal human heart was used for experimental validation by employing simultaneous optical particle image velocimetry as a standard reference technique. Finally, the applicability of the approach was tested in a clinical setting. On the basis of the simulated data, pointwise evaluation of the estimated velocity vectors correlated well (mean r = 0.84) with the computational fluid dynamics measurement. During the filling period of the left ventricle, the properties of the main vortex obtained from the proposed method were also measured, and their correlations with the reference measurement were also calculated (radius, r = 0.96; circulation, r = 0.85; weighted center, r = 0.81). In vitro results at 60 bpm during one cardiac cycle confirmed that the algorithm properly measures typical characteristics of the vortex (radius, r = 0.60; circulation, r = 0.81; weighted center, r = 0.92). Preliminary qualitative results on clinical data revealed physiologic flow fields.
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Affiliation(s)
- Hang Gao
- Lab on Cardiovascular Imaging and Dynamics, KU Leuven, Leuven, Belgium.
| | - Nathalie Bijnens
- Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Damien Coisne
- University Hospital of Poitiers-Hospital of La Miletrie, Poitiers, France
| | | | - Marcel Rutten
- Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Jan D'hooge
- Lab on Cardiovascular Imaging and Dynamics, KU Leuven, Leuven, Belgium
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Pedrizzetti G, Domenichini F. Left Ventricular Fluid Mechanics: The Long Way from Theoretical Models to Clinical Applications. Ann Biomed Eng 2014; 43:26-40. [PMID: 25186434 DOI: 10.1007/s10439-014-1101-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 08/25/2014] [Indexed: 12/25/2022]
Affiliation(s)
- Gianni Pedrizzetti
- Dipartimento di Ingegneria e Architettura, University of Trieste, P.le Europa 1, 34127, Trieste, Italy,
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de Vecchi A, Gomez A, Pushparajah K, Schaeffter T, Nordsletten DA, Simpson JM, Penney GP, Smith NP. Towards a fast and efficient approach for modelling the patient-specific ventricular haemodynamics. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2014; 116:3-10. [PMID: 25157924 DOI: 10.1016/j.pbiomolbio.2014.08.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 08/12/2014] [Indexed: 11/17/2022]
Abstract
Computer modelling of the heart has emerged over the past decade as a powerful technique to explore the cardiovascular pathophysiology and inform clinical diagnosis. The current state-of-the-art in biophysical modelling requires a wealth of, potentially invasive, clinical data for the parametrisation and validation of the models, a process that is still too long and complex to be compatible with the clinical decision-making time. Therefore, there remains a need for models that can be quickly customised to reconstruct physical processes difficult to measure directly in patients. In this paper, we propose a less resource-intensive approach to modelling, whereby computational fluid-dynamics (CFD) models are constrained exclusively by boundary motion derived from imaging data through a validated wall tracking algorithm. These models are generated and parametrised based solely on ultrasound data, whose acquisition is fast, inexpensive and routine in all patients. To maximise the time and computational efficiency, a semi-automated pipeline is embedded in an image processing workflow to personalise the models. Applying this approach to two patient cases, we demonstrate this tool can be directly used in the clinic to interpret and complement the available clinical data by providing a quantitative indication of clinical markers that cannot be easily derived from imaging, such as pressure gradients and the flow energy.
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Affiliation(s)
- A de Vecchi
- Division of Imaging Sciences and Biomedical Engineering, King's College London, St. Thomas' Hospital, London SE1 7EH, UK
| | - A Gomez
- Division of Imaging Sciences and Biomedical Engineering, King's College London, St. Thomas' Hospital, London SE1 7EH, UK
| | - K Pushparajah
- Evelina London Children's Hospital, London SE1 7EH, UK
| | - T Schaeffter
- Division of Imaging Sciences and Biomedical Engineering, King's College London, St. Thomas' Hospital, London SE1 7EH, UK
| | - D A Nordsletten
- Division of Imaging Sciences and Biomedical Engineering, King's College London, St. Thomas' Hospital, London SE1 7EH, UK
| | - J M Simpson
- Evelina London Children's Hospital, London SE1 7EH, UK
| | - G P Penney
- Division of Imaging Sciences and Biomedical Engineering, King's College London, St. Thomas' Hospital, London SE1 7EH, UK
| | - N P Smith
- Division of Imaging Sciences and Biomedical Engineering, King's College London, St. Thomas' Hospital, London SE1 7EH, UK.
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Prolonged vortex formation during the ejection period in the left ventricle with low ejection fraction: a study by vector flow mapping. J Med Ultrason (2001) 2014; 41:301-10. [DOI: 10.1007/s10396-014-0530-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 01/15/2014] [Indexed: 10/25/2022]
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Hong GR, Kim M, Pedrizzetti G, Vannan MA. Current clinical application of intracardiac flow analysis using echocardiography. J Cardiovasc Ultrasound 2013; 21:155-62. [PMID: 24459561 PMCID: PMC3894365 DOI: 10.4250/jcu.2013.21.4.155] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 12/23/2013] [Accepted: 12/23/2013] [Indexed: 11/22/2022] Open
Abstract
In evaluating the cardiac function, it is important to have a comprehensive assessment of structural factors, such as the myocardial or valvular function and intracardiac flow dynamics that pass the heart. Vortex flow that form during left ventricular filling have specific geometry and anatomical location that are critical determinants of directed blood flow during ejection. The formation of abnormal vortices relates to the abnormal cardiac function. Therefore, vortex flow may offer a novel index of cardiac dysfunction. Intracardiac flow visualization using ultrasound technique has definite advantages with a higher temporal resolution and availability in real time clinical setting. Vector flow mapping based on color-Doppler and contrast echocardiography using particle image velocimetry is currently being used for visualizing the intracardiac flow. The purpose of this review is to provide readers with an update on the current method for analyzing intracardiac flow using echocardiography and its clinical applications.
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Affiliation(s)
- Geu-Ru Hong
- Division of Cardiology, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Minji Kim
- School of Medicine, University of Queensland, Herston, QLD, Australia
| | | | - Mani A Vannan
- Department of Cardiovascular Medicine, Piedmont Heart Institute, Atlanta, GA, USA
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Ghosh E, Kovács SJ. The vortex formation time to diastolic function relation: assessment of pseudonormalized versus normal filling. Physiol Rep 2013; 1:e00170. [PMID: 24400169 PMCID: PMC3871482 DOI: 10.1002/phy2.170] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 10/30/2013] [Accepted: 11/01/2013] [Indexed: 01/18/2023] Open
Abstract
In early diastole, the suction pump feature of the left ventricle opens the mitral valve and aspirates atrial blood. The ventricle fills via a blunt profiled cylindrical jet of blood that forms an asymmetric toroidal vortex ring inside the ventricle whose growth has been quantified by the standard (dimensionless) expression for vortex formation time, VFTstandard = {transmitral velocity time integral}/{mitral orifice diameter}. It can differentiate between hearts having distinguishable early transmitral (Doppler E-wave) filling patterns. An alternative validated expression, VFTkinematic reexpresses VFTstandard by incorporating left heart, near “constant-volume pump” physiology thereby revealing VFTkinematic's explicit dependence on maximum rate of longitudinal chamber expansion (E′). In this work, we show that VFTkinematic can differentiate between hearts having indistinguishable E-wave patterns, such as pseudonormal (PN; 0.75 < E/A < 1.5 and E/E′ > 8) versus normal. Thirteen age-matched normal and 12 PN data sets (738 total cardiac cycles), all having normal LVEF, were selected from our Cardiovascular Biophysics Laboratory database. Doppler E-, lateral annular E′-waves, and M-mode data (mitral leaflet separation, chamber dimension) was used to compute VFTstandard and VFTkinematic. VFTstandard did not differentiate between groups (normal [3.58 ± 1.06] vs. PN [4.18 ± 0.79], P = 0.13). In comparison, VFTkinematic for normal (3.15 ± 1.28) versus PN (4.75 ± 1.35) yielded P = 0.006. Hence, the applicability of VFTkinematic for diastolic function quantitation has been broadened to include analysis of PN filling patterns in age-matched groups.
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Affiliation(s)
- Erina Ghosh
- Department of Biomedical Engineering, School of Engineering and Applied Science, Washington University in St Louis St. Louis, Missouri
| | - Sándor J Kovács
- Department of Biomedical Engineering, School of Engineering and Applied Science, Washington University in St Louis St. Louis, Missouri ; Cardiovascular Biophysics Laboratory, Cardiovascular Division, Department of Internal Medicine, School of Medicine, Washington University in St Louis St. Louis, Missouri
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Rodriguez Muñoz D, Markl M, Moya Mur JL, Barker A, Fernández-Golfín C, Lancellotti P, Zamorano Gómez JL. Intracardiac flow visualization: current status and future directions. Eur Heart J Cardiovasc Imaging 2013; 14:1029-38. [PMID: 23907342 DOI: 10.1093/ehjci/jet086] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Non-invasive cardiovascular imaging initially focused on heart structures, allowing the visualization of their motion and inferring its functional status from it. Colour-Doppler and cardiac magnetic resonance (CMR) have allowed a visual approach to intracardiac flow behaviour, as well as measuring its velocity at single selected spots. Recently, the application of new technologies to medical use and, particularly, to cardiology has allowed, through different algorithms in CMR and applications of ultrasound-related techniques, the description and analysis of flow behaviour in all points and directions of the selected region, creating the opportunity to incorporate new data reflecting cardiac performance to cardiovascular imaging. The following review provides an overview of the currently available imaging techniques that enable flow visualization, as well as its present and future applications based on the available literature and on-going works.
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Affiliation(s)
- Daniel Rodriguez Muñoz
- Department of Cardiology, Ramón y Cajal University Hospital, Ctra. de Colmenar, Km 9, 100, PO 28031 Madrid, Spain
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Le TB, Sotiropoulos F. Fluid-structure interaction of an aortic heart valve prosthesis driven by an animated anatomic left ventricle. JOURNAL OF COMPUTATIONAL PHYSICS 2013; 244:41-62. [PMID: 23729841 PMCID: PMC3667163 DOI: 10.1016/j.jcp.2012.08.036] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
We develop a novel large-scale kinematic model for animating the left ventricle (LV) wall and use this model to drive the fluid-structure interaction (FSI) between the ensuing blood flow and a mechanical heart valve prosthesis implanted in the aortic position of an anatomic LV/aorta configuration. The kinematic model is of lumped type and employs a cell-based, FitzHugh-Nagumo framework to simulate the motion of the LV wall in response to an excitation wavefront propagating along the heart wall. The emerging large-scale LV wall motion exhibits complex contractile mechanisms that include contraction (twist) and expansion (untwist). The kinematic model is shown to yield global LV motion parameters that are well within the physiologic range throughout the cardiac cycle. The FSI between the leaflets of the mechanical heart valve and the blood flow driven by the dynamic LV wall motion and mitral inflow is simulated using the curvilinear immersed boundary (CURVIB) method [1, 2] implemented in conjunction with a domain decomposition approach. The computed results show that the simulated flow patterns are in good qualitative agreement with in vivo observations. The simulations also reveal complex kinematics of the valve leaflets, thus, underscoring the need for patient-specific simulations of heart valve prosthesis and other cardiac devices.
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Affiliation(s)
- Trung Bao Le
- Saint Anthony Falls Laboratory, Department of Civil Engineering, University of Minnesota, 2 Third Ave SE, Minneapolis, MN 55414
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Pagel PS, Hudetz JA. Chronic pressure-overload hypertrophy attenuates vortex formation time in patients with severe aortic stenosis and preserved left ventricular systolic function undergoing aortic valve replacement. J Cardiothorac Vasc Anesth 2013; 27:660-4. [PMID: 23727466 DOI: 10.1053/j.jvca.2013.01.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Indexed: 01/19/2023]
Abstract
OBJECTIVE Transmitral blood flow produces a vortex ring that enhances the hydraulic efficiency of early left ventricular (LV) filling. The effect of pressure-overload hypertrophy on the duration of LV vortex ring formation (vortex formation time [VFT]) is unknown. The current investigation tested the hypothesis that chronic LV pressure-overload hypertrophy produced by severe aortic stenosis (AS) reduces VFT in patients with preserved LV systolic function undergoing aortic valve replacement. DESIGN Observational study. SETTING Veterans Affairs Medical Center. PARTICIPANTS After the Institutional Review Board's approval, 8 patients (7 men and 1 woman; age, 62±5 y; and ejection fraction, 59%±5%) with AS (peak pressure gradient, 81±22 mmHg; aortic valve area, 0.78±0.25 cm(2)) scheduled for aortic valve replacement were compared with 8 patients (all men; age, 63±3 y; and ejection fraction, 60%±7%) without AS undergoing coronary artery bypass graft surgery. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Under general anesthesia, peak early LV filling (E) and atrial systole (A) blood flow velocities and their corresponding velocity-time integrals were obtained using pulse-wave Doppler echocardiography to determine E/A and atrial filling fraction (β). Mitral valve diameter (D) was calculated as the average of minor and major axis lengths obtained in the midesophageal bicommissural and long-axis transesophageal echocardiography imaging planes, respectively. Posterior wall thickness (PWT) was measured at end-diastole using M-mode echocardiography. VFT was calculated as 4×(1-β)×SV/πD(3), where SV = stroke volume measured using thermodilution. Systemic and pulmonary hemodynamics, LV diastolic function, PWT, and VFT were determined during steady-state conditions 30 minutes before cardiopulmonary bypass. Early LV filling was attenuated in patients with AS (eg, E/A, 0.77±0.11 compared with 1.23±0.13; β, 0.43±0.09 compared with 0.35±0.02; p<0.05 for each). LV hypertrophy was observed (PWT, 1.4±0.1 cm compared with 1.1±0.2 cm; p<0.05) and VFT was lower (3.0±0.9 v 4.3±0.5; p<0.05) in patients with versus without AS. Linear regression analysis showed a significant correlation between VFT and PWT (VFT = -2.57 ×PWT + 6.81; r(2) = 0.345; p = 0.017). CONCLUSION The results indicated that pressure-overload hypertrophy produced by AS reduced VFT in patients with normal LV systolic function undergoing aortic valve replacement.
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Affiliation(s)
- Paul S Pagel
- Anesthesia Service, Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, WI 53295, USA.
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36
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Van Der Smissen B, Claessens T, Verdonck P, Van Ransbeeck P, Segers P. Modelling the left ventricle using rapid prototyping techniques. Ing Rech Biomed 2013. [DOI: 10.1016/j.irbm.2013.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abe H, Caracciolo G, Kheradvar A, Pedrizzetti G, Khandheria BK, Narula J, Sengupta PP. Contrast echocardiography for assessing left ventricular vortex strength in heart failure: a prospective cohort study. ACTA ACUST UNITED AC 2013; 14:1049-60. [DOI: 10.1093/ehjci/jet049] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Amaki M, Abe H, Sengupta PP. Visualization of blood flow with echocardiography: the future for heart failure diagnosis. Interv Cardiol 2012. [DOI: 10.2217/ica.12.54] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Zhang H, Liu L, Chen L, Ma N, Zhou L, Liu Y, Li Z, Liu C, Hou R, Zhu S. The evolution of intraventricular vortex during ejection studied by using vector flow mapping. Echocardiography 2012; 30:27-36. [PMID: 22985123 DOI: 10.1111/j.1540-8175.2012.01806.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
AIMS The purpose of this study was to assess the evolution of intraventricular vortex during left ventricular (LV) ejection. METHODS Vector flow mapping was performed in 51 patients with coronary artery disease and LV ejection fraction (EF) >50%, 70 patients with EF <50% (13 with coronary artery disease and 57 with dilated cardiomyopathy), and 62 healthy volunteers. RESULTS In normals and patients with EF >50%, the intraventricular vortex dissipated quickly during early ejection. In patients with EF <50%, the vortex stayed mainly at apex and persisted for a significantly longer time. The evolution of vortex during ejection was significantly correlated with QRS width, EF, fractional shortening, LV outflow velocity time integral, wall motion score index (WMSI), LV dimensions, left atrial diameter, and diastolic mitral annular velocities. LV end-diastolic short diameter and WMSI were the independent determinants of the duration of vortex (R(2) = 0.482, P < 0.001). End-systolic short diameter and apical WMSI were the independent determinants of duration of vortex corrected for ejection time (R(2) = 0.565, P < 0.001). End-systolic short diameter was the independent determinant of percentage change in vortex area during early ejection (R(2) = 0.355, P < 0.001). End-systolic short diameter and ejection time were the independent determinants of percentage change in vortex flow volume (R(2) = 0.415, P < 0.001). CONCLUSIONS In patients with LV systolic dysfunction, the vortex persists during ejection and stays mainly at apex. The vortex evolution during ejection is closely associated with LV dimensions and functions.
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Affiliation(s)
- Haibin Zhang
- Department of Ultrasound, PLA 210th Hospital, Dalian, China
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Töger J, Kanski M, Carlsson M, Kovács SJ, Söderlind G, Arheden H, Heiberg E. Vortex ring formation in the left ventricle of the heart: analysis by 4D flow MRI and Lagrangian coherent structures. Ann Biomed Eng 2012; 40:2652-62. [PMID: 22805980 DOI: 10.1007/s10439-012-0615-3] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Accepted: 06/28/2012] [Indexed: 10/28/2022]
Abstract
Recent studies suggest that vortex ring formation during left ventricular (LV) rapid filling is an optimized mechanism for blood transport, and that the volume of the vortex ring is an important measure. However, due to lack of quantitative methods, the volume of the vortex ring has not previously been studied. Lagrangian Coherent Structures (LCS) is a new flow analysis method, which enables in vivo quantification of vortex ring volume. Therefore, we aimed to investigate if vortex ring volume in the human LV can be reliably quantified using LCS and magnetic resonance velocity mapping (4D PC-MR). Flow velocities were measured using 4D PC-MR in 9 healthy volunteers and 4 patients with dilated ischemic cardiomyopathy. LV LCS were computed from flow velocities and manually delineated in all subjects. Vortex volume in the healthy volunteers was 51 ± 6% of the LV volume, and 21 ± 5% in the patients. Interobserver variability was -1 ± 13% and interstudy variability was -2 ± 12%. Compared to idealized flow experiments, the vortex rings showed additional complexity and asymmetry, related to endocardial trabeculation and papillary muscles. In conclusion, LCS and 4D PC-MR enables measurement of vortex ring volume during rapid filling of the LV.
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Affiliation(s)
- Johannes Töger
- Department of Clinical Physiology, Skåne University Hospital Lund, Lund University, 221 85, Lund, Sweden
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41
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Chen R, Zhao BW, Wang B, Tang HL, Li P, Pan M, Xu LL. Assessment of left ventricular hemodynamics and function of patients with uremia by vortex formation using vector flow mapping. Echocardiography 2012; 29:1081-90. [PMID: 22694735 DOI: 10.1111/j.1540-8175.2012.01737.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
A novel echocardiographic method, vector flow mapping (VFM), acquires velocity vector from color Doppler velocity data. The purpose of this study was to evaluate whether VFM could provide useful information on intracardiac flow and helpful to evaluate left ventricular (LV) function. Thirty-eight patients with uremia undergoing hemodialysis and 30 healthy volunteers were enrolled. The maximum vector velocity, maximum diameter and duration of the intracardiac vortex were measured using VFM software during systole and diastole. The maximum vector velocity of the vortex and the peak velocities at the basal septum and lateral mitral annulus measured by tissue Doppler imaging (TDI) were correlated. The maximum diameter and duration of vortex formation were significantly higher in uremic patients compared with the control group during the ejection phase (40.6 ± 7.9 cm/sec vs. 28.1 ± 3.9 cm/sec; 297.1 ± 22.1 msec vs. 145.4 ± 19.3 msec, all P < 0.001). The maximal diameters of the vortex were higher in uremic patients compared with the control group during diastole (25.6 ± 3.4 mm vs. 16.4 ± 2.1 mm; 34.3 ± 3.1 mm vs. 26.8 ± 3.9 mm; 37.5 ± 2.4 mm vs. 20.9 ± 2.1 mm; all P < 0.001). The maximum vector velocities were lower in mid-diastole and late diastole (23.6 ± 2.3 cm/sec vs. 45.2 ± 3.7 cm/sec; 31.9 ± 2.9 cm/sec vs. 54.7 ± 3.2 cm/sec, all P < 0.001). There was a correlation between the maximum vector velocity of the vortex in mid-diastole and E'/A' at the septum and lateral mitral annulus (r = 0.70, r = 0.76, P < 0.001). Vortex can be utilized to provide intracardiac dynamic information using VFM and it may be a good supplement for evaluating LV function.
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Affiliation(s)
- Ran Chen
- Department of Diagnostic Ultrasound and Echocardiography, Sir Run Run Shaw Hospital, Zhejiang University College of Medicine and Sir Run Run Shaw Institute of Clinical Medicine of Zhejiang University, Hangzhou, China
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Pagel PS, Gandhi SD, Iqbal Z, Hudetz JA. Cardiopulmonary Bypass Transiently Inhibits Intraventricular Vortex Ring Formation in Patients Undergoing Coronary Artery Bypass Graft Surgery. J Cardiothorac Vasc Anesth 2012; 26:376-80. [DOI: 10.1053/j.jvca.2011.10.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Indexed: 11/11/2022]
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Rausch MK, Bothe W, Kvitting JPE, Swanson JC, Miller DC, Kuhl E. Mitral valve annuloplasty: a quantitative clinical and mechanical comparison of different annuloplasty devices. Ann Biomed Eng 2012; 40:750-61. [PMID: 22037916 PMCID: PMC3288426 DOI: 10.1007/s10439-011-0442-y] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Accepted: 10/08/2011] [Indexed: 10/16/2022]
Abstract
Mitral valve annuloplasty is a common surgical technique used in the repair of a leaking valve by implanting an annuloplasty device. To enhance repair durability, these devices are designed to increase leaflet coaptation, while preserving the native annular shape and motion; however, the precise impact of device implantation on annular deformation, strain, and curvature is unknown. In this article, we quantify how three frequently used devices significantly impair native annular dynamics. In controlled in vivo experiments, we surgically implanted 11 flexible-incomplete, 11 semi-rigid-complete, and 12 rigid-complete devices around the mitral annuli of 34 sheep, each tagged with 16 equally spaced tantalum markers. We recorded four-dimensional marker coordinates using biplane videofluoroscopy, first with device and then without, which were used to create mathematical models using piecewise cubic splines. Clinical metrics (characteristic anatomical distances) revealed significant global reduction in annular dynamics upon device implantation. Mechanical metrics (strain and curvature fields) explained this reduction via a local loss of anterior dilation and posterior contraction. Overall, all three devices unfavorably caused reduction in annular dynamics. The flexible-incomplete device, however, preserved native annular dynamics to a larger extent than the complete devices. Heterogeneous strain and curvature profiles suggest the need for heterogeneous support, which may spawn more rational design of annuloplasty devices using design concepts of functionally graded materials.
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Affiliation(s)
- Manuel K Rausch
- Department of Mechanical Engineering, Stanford University, 496 Lomita Mall, Stanford, CA 94305, USA
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Sengupta PP, Pedrizzetti G, Kilner PJ, Kheradvar A, Ebbers T, Tonti G, Fraser AG, Narula J. Emerging Trends in CV Flow Visualization. JACC Cardiovasc Imaging 2012; 5:305-16. [PMID: 22421178 DOI: 10.1016/j.jcmg.2012.01.003] [Citation(s) in RCA: 169] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 01/06/2012] [Accepted: 01/09/2012] [Indexed: 11/18/2022]
Affiliation(s)
- Partho P Sengupta
- Zena and Michael A. Wiener Cardiovascular Institute, Mount Sinai School of Medicine, New York, NY 10029, USA.
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Zhang H, Zhang J, Zhu X, Chen L, Liu L, Duan Y, Yu M, Zhou X, Zhu T, Zhu M, Li H. The left ventricular intracavitary vortex during the isovolumic contraction period as detected by vector flow mapping. Echocardiography 2012; 29:579-87. [PMID: 22324480 DOI: 10.1111/j.1540-8175.2011.01649.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
AIMS The purpose of this study was to characterize left ventricular (LV) intracavitary flow during the isovolumic contraction (IVC) period in humans using vector flow mapping. METHODS Color flow Doppler imaging was performed from the apical long-axis view in 61 patients with heart failure and 58 healthy volunteers. Doppler flow data obtained during IVC were analyzed offline with vector flow mapping. RESULTS A large vortex was formed from the LV inflow toward the outflow during IVC. In normal subjects, the area of the vortex was sustained, but the flow volume decreased significantly during IVC (P < 0.001). A significant apex-to-base flow velocity gradient was shown along the outflow axis on aortic valve opening. However, both the area and flow volume of the vortex decreased more severely during IVC in the patients (P < 0.001). The apex-to-base flow velocity gradient along the outflow axis disappeared and a reversed velocity gradient was observed at the basal-mid level on aortic valve opening. In multivariate models, a decreased LV ejection fraction was the only independent predictor of the percentage decrease in area of the vortex during the IVC (P < 0.001), and a larger QRS width (P = 0.028) and LV end-systolic long diameter (P = 0.002) were independent predictors of the percentage decrease in flow volume of the vortex. CONCLUSIONS The vortex across the LV inflow-outflow region during IVC facilitates the ejection of blood during early systole, and an unsustained vortex may be associated with impaired cardiac function.
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Affiliation(s)
- Haibin Zhang
- Department of Ultrasound, PLA 210th Hospital, Dalian, China
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46
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Assessment of Transmitral Vortex Formation in Patients with Diastolic Dysfunction. J Am Soc Echocardiogr 2012; 25:220-7. [DOI: 10.1016/j.echo.2011.10.003] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Indexed: 11/19/2022]
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47
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Cave AL, Skubas NJ. Mitral regurgitation in acute aortic insufficiency. J Cardiothorac Vasc Anesth 2012; 26:1153-5. [PMID: 22226418 DOI: 10.1053/j.jvca.2011.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Indexed: 11/11/2022]
Affiliation(s)
- Anita L Cave
- Department of Anesthesiology, New York-Presbyterian Hospital, New York, NY, USA.
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Characterization of Mitral Valve Annular Dynamics in the Beating Heart. Ann Biomed Eng 2011; 39:1690-702. [DOI: 10.1007/s10439-011-0272-y] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Accepted: 02/04/2011] [Indexed: 11/25/2022]
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Sengupta SP, Sengupta PP, Narula J. Echocardiographic Investigations of Myocardial Function in Mitral Stenosis: Making Sense of the Echolalia. Cardiology 2011; 119:142-4. [DOI: 10.1159/000331404] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/29/2011] [Indexed: 11/19/2022]
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Ghosh E, Shmuylovich L, Kovács SJ. Vortex formation time-to-left ventricular early rapid filling relation: model-based prediction with echocardiographic validation. J Appl Physiol (1985) 2010; 109:1812-9. [DOI: 10.1152/japplphysiol.00645.2010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
During early rapid filling, blood aspirated by the left ventricle (LV) generates an asymmetric toroidal vortex whose development has been quantified using vortex formation time (VFT), a dimensionless index defined by the length-to-diameter ratio of the aspirated (equivalent cylindrical) fluid column. Since LV wall motion generates the atrioventricular pressure gradient resulting in the early transmitral flow (Doppler E-wave) and associated vortex formation, we hypothesized that the causal relation between VFT and diastolic function (DF), parametrized by stiffness, relaxation, and load, can be elucidated via kinematic modeling. Gharib et al. (Gharib M, Rambod E, Kheradvar A, Sahn DJ, Dabiri JO. Proc Natl Acad Sci USA 103: 6305–6308, 2006) approximated E-wave shape as a triangle and calculated VFTGharib as triangle (E-wave) area (cm) divided by peak (Doppler M-mode derived) mitral orifice diameter (cm). We used a validated kinematic model of filling for the E-wave as a function of time, parametrized by stiffness, viscoelasticity, and load. To calculate VFTkinematic, we computed the curvilinear E-wave area (using the kinematic model) and divided it by peak effective orifice diameter. The derived VFT-to-LV early rapid filling relation predicts VFT to be a function of peak E-wave-to-peak mitral annular tissue velocity (Doppler E′-wave) ratio as (E/E′)3/2. Validation utilized 262 cardiac cycles of simultaneous echocardiographic high-fidelity hemodynamic data from 12 subjects. VFTGharib and VFTkinematic were calculated for each subject and were well-correlated ( R2 = 0.66). In accordance with prediction, VFTkinematic to (E/E′)3/2 relationship was validated ( R 2 = 0.63). We conclude that VFTkinematic is a DF index computable in terms of global kinematic filling parameters of stiffness, viscoelasticity, and load. Validation of the fluid mechanics-to-chamber kinematics relation unites previously unassociated DF assessment methods and elucidates the mechanistic basis of the strong correlation between VFT and (E/E′)3/2.
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Affiliation(s)
- Erina Ghosh
- Department of Biomedical Engineering, School of Engineering and Applied Science, and
| | - Leonid Shmuylovich
- Department of Physics, College of Arts and Sciences, Washington University, St. Louis, Missouri
| | - Sándor J. Kovács
- Cardiovascular Biophysics Laboratory, Cardiovascular Division, Department of Internal Medicine, School of Medicine,
- Department of Biomedical Engineering, School of Engineering and Applied Science, and
- Department of Physics, College of Arts and Sciences, Washington University, St. Louis, Missouri
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