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Rodríguez-Aparicio S, Ferrera C, Millán-Núñez MV, García García J, Dueñas-Pamplona J. Influence of the flow split ratio on the position of the main atrial vortex: Implications for stasis on the left atrial appendage. Comput Biol Med 2024; 178:108772. [PMID: 38917532 DOI: 10.1016/j.compbiomed.2024.108772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 05/17/2024] [Accepted: 06/15/2024] [Indexed: 06/27/2024]
Abstract
BACKGROUND Despite the recent advances in computational fluid dynamics (CFD) techniques applied to blood flow within the left atrium (LA), the relationship between atrial geometry, flow patterns, and blood stasis within the left atrial appendage (LAA) remains unclear. A better understanding of this relationship would have important clinical implications, as thrombi originating in the LAA are a common cause of stroke in patients with atrial fibrillation (AF). AIM To identify the most representative atrial flow patterns on a patient-specific basis and study their influence on LAA blood stasis by varying the flow split ratio and some common atrial modeling assumptions. METHODS Three recent techniques were applied to nine patient-specific computational fluid dynamics (CFD) models of patients with AF: a kinematic atrial model to isolate the influence of wall motion because of AF, projection on a universal LAA coordinate system, and quantification of stagnant blood volume (SBV). RESULTS We identified three different atrial flow patterns based on the position of the center of the main circulatory flow. The results also illustrate how atrial flow patterns are highly affected by the flow split ratio, increasing the SBV within the LAA. As the flow split ratio is determined by the patient's lying position, the results suggest that the most frequent position adopted while sleeping may have implications for the medium- and long-term risks of stroke.
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Affiliation(s)
- Sergio Rodríguez-Aparicio
- Departamento de Ingeniería Mecánica, Energética y de los Materiales, Universidad de Extremadura, Avda. Elvas s/n, Badajoz 06006, Spain
| | - Conrado Ferrera
- Departamento de Ingeniería Mecánica, Energética y de los Materiales, Universidad de Extremadura, Avda. Elvas s/n, Badajoz 06006, Spain; Instituto de Computación Científica Avanzada (ICCAEX), Avda. Elvas s/n, Badajoz 06006, Spain
| | | | - Javier García García
- Departamento de Ingeniería Energética, Universidad Politécnica de Madrid, Avda. de Ramiro de Maeztu 7, Madrid 28040, Spain
| | - Jorge Dueñas-Pamplona
- Departamento de Ingeniería Energética, Universidad Politécnica de Madrid, Avda. de Ramiro de Maeztu 7, Madrid 28040, Spain.
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Fernández-Martínez D, González-Fernández MR, Nogales-Asensio JM, Ferrera C. Impact of minimal lumen segmentation uncertainty on patient-specific coronary simulations: A look at FFR CT. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2024; 40:e3822. [PMID: 38566253 DOI: 10.1002/cnm.3822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 02/20/2024] [Accepted: 03/24/2024] [Indexed: 04/04/2024]
Abstract
We examined the effect of minimal lumen segmentation uncertainty on Fractional Flow Reserve obtained from Coronary Computed Tomography AngiographyFFR CT . A total of 14 patient-specific coronary models with different stenosis locations and degrees of severity were enrolled in this study. The optimal segmented coronary lumens were disturbed using intra± 6 % and inter-operator± 15 % variations on the segmentation threshold.FFR CT was evaluated in each case by 3D-OD CFD simulations. The findings suggest that the sensitivity ofFFR CT to this type of uncertainty increases distally and with the stenosis severity. Cases with moderate or severe distal coronary lesions should undergo either exact and thorough segmentation operations or invasive FFR measurements, particularly if theFFR CT is close to the cutoff (0.80). Therefore, we conclude that it is crucial to consider the lesion's location and degree of severity when evaluatingFFR CT results.
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Affiliation(s)
- Daniel Fernández-Martínez
- Departamento de Ingeniería Mecánica, Energética y de los Materiales, Universidad de Extremadura, Badajoz, Spain
| | | | | | - Conrado Ferrera
- Departamento de Ingeniería Mecánica, Energética y de los Materiales, Universidad de Extremadura, Badajoz, Spain
- Instituto de Computación Científica Avanzada, Universidad de Extremadura, Badajoz, Spain
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Udupa MC, Saha S, Natarajan S. Numerical simulation of the blood flow through a pre-stenotic aneurysm in coronary artery: effects of varying heart rate. Comput Methods Biomech Biomed Engin 2024; 27:459-477. [PMID: 38146852 DOI: 10.1080/10255842.2023.2297659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 12/08/2023] [Indexed: 12/27/2023]
Abstract
The left anterior descending artery (LAD) is a significant coronary artery and a facilitator of oxygenated blood to the heart muscles. Thus, any occurrence of an aneurysm in LAD requires immediate medical attention. It is often inclined toward fatality if coupled with a blockage due to stenosis. Given the high relevance of understanding such models, invasive techniques under all parametric circumstances are hard to achieve. So, a theoretical approach with a cost-effective intervention of mathematical modeling becomes essential. In our current work, we analyze the model with the numerical technique of a modified form of SIMPLE pressure-correction based algorithm and perform parametric studies for the flow field with degree of stenosis, degree of aneurysm, heart rate, and distance separating aneurysm and stenosis as parameters. The study reveals a direct proportionality relation between the number of recirculation zones and heart rate through instantaneous streamline plots. Alongside this, the demonstration of an increase in the risk of rupture of the aneurysm with a decrease in the distance between stenosis and aneurysm, using the physical parameters associated with blood flow, is another key finding. Further, we examine the effect of the flow field on heat transfer and the consequent temperature profiles.
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Affiliation(s)
- Mahesh C Udupa
- Department of Mathematics, SAS, VIT Vellore, Tamil Nadu, India
| | - Sunanda Saha
- Centre for Clean Environment, VIT Vellore, Tamil Nadu, India
| | - Sekarapandian Natarajan
- Department of Thermal and Energy, School of Mechanical Engineering, VIT Vellore, Tamil Nadu, India
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Agujetas R, Ferrera C, González-Fernández R, Nogales-Asensio JM, Fernández-Tena A. Influence of the position of the distal pressure measurement point on the Fractional Flow Reserve using in-silico simulations. Biocybern Biomed Eng 2022. [DOI: 10.1016/j.bbe.2022.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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He W, Yu L, Qin W, Wang Y, Wang K, Guo W, Wang S. A modified method of noninvasive computed tomography derived fractional flow reserve based on the microvascular growth space. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2022; 221:106926. [PMID: 35701250 DOI: 10.1016/j.cmpb.2022.106926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 05/29/2022] [Accepted: 05/30/2022] [Indexed: 06/15/2023]
Abstract
OBJECTIVE To establish a modified method for optimizing outlet boundary conditions (BC) of computed tomography-derived fractional flow reserve (CT-FFR), considering the myocardium as a growth space for microcirculation. The feasibility and diagnostic performance of the modified method in stable coronary artery disease (CAD) were compared with invasive fractional flow reserve (FFR). METHODS Nineteen patients (19 lesions) underwent coronary computed tomography angiography (CCTA) and following invasive FFR were included. The microcirculation resistance model generated based on patient-specific anatomical structures and physiological principles was used as the outlet BC, considering the myocardium as a growth space. Brachial artery pressure (BAP) plus or minus 10 mmHg was used as the inlet pressure BC to investigate the effect of the circadian rhythm. After simulation, CT-FFR was compared with invasive FFR with a threshold of 0.80. RESULTS Compared with invasive FFR, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of CT-FFR with an optimal threshold of 0.80 were 100%, 100%, 100%, 100%, 100%, respectively. There were a good correlation and consistency between CT-FFR and invasive FFR. Little effect of the circadian fluctuation of BAP was found on the simulation. CONCLUSIONS A modified method for CT-FFR with high diagnostic accuracy compared with invasive FFR was established, considering the whole myocardial as the growth space for microcirculation. Circadian fluctuations in BAP could be ignored when it was used as the inlet BC.
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Affiliation(s)
- Wei He
- Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Long Yu
- Department of aeronautics and astronautics, Fudan University, Shanghai, China
| | - Wang Qin
- Department of aeronautics and astronautics, Fudan University, Shanghai, China
| | - Yuan Wang
- School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Keqiang Wang
- Institute of Panvascular Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Weifeng Guo
- Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai, China.
| | - Shengzhang Wang
- Department of aeronautics and astronautics, Fudan University, Shanghai, China; Institute of Biomedical Engineering Technology, Academy for Engineering and Technology, Fudan University, Shanghai, China; Yiwu Research Institute, Fudan University, Yiwu, China.
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Freitas SA, Nienow D, da Costa CA, Ramos GDO. Functional Coronary Artery Assessment: a Systematic Literature Review. Wien Klin Wochenschr 2021; 134:302-318. [PMID: 34870740 DOI: 10.1007/s00508-021-01970-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 10/11/2021] [Indexed: 11/28/2022]
Abstract
Cardiovascular diseases represent the number one cause of death in the world, including the most common disorders in the heart's health, namely coronary artery disease (CAD). CAD is mainly caused by fat accumulated in the arteries' internal walls, creating an atherosclerotic plaque that impacts the blood flow functional behavior. Anatomical plaque characteristics are essential but not sufficient for a complete functional assessment of CAD. In fact, plaque analysis and visual inspection alone have proven insufficient to determine the lesion severity and hemodynamic repercussion. Furthermore, the fractional flow reserve (FFR) exam, which is considered the gold standard for stenosis functional impair determination, is invasive and contains several limitations. Such a panorama evidences the need for new techniques applied to image exams to improve CAD functional assessment. In this article, we perform a systematic literature review on emerging methods determining CAD significance, thus delivering a unique base for comparing these methods, qualitatively and quantitatively. Our goal is to guide further studies with evidence from the most promising methods, highlighting the benefits from both areas. We summarize benchmarks, metrics for evaluation, and challenges already faced, thus shedding light on the requirements for a valid, meaningful, and accepted technique for functional assessment evaluation. We create a base of comparison based on quantitative and qualitative indicators and highlight the most relevant geometrical metrics that correlate with lesion significance. Finally, we point out future benchmarks based on recent literature.
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Affiliation(s)
- Samuel A Freitas
- Software Innovation Laboratory, Graduate Program in Applied Computing, Universidade do Vale do Rio dos Sinos, São Leopoldo, Brazil
| | - Débora Nienow
- Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Cristiano A da Costa
- Software Innovation Laboratory, Graduate Program in Applied Computing, Universidade do Vale do Rio dos Sinos, São Leopoldo, Brazil
| | - Gabriel de O Ramos
- Software Innovation Laboratory, Graduate Program in Applied Computing, Universidade do Vale do Rio dos Sinos, São Leopoldo, Brazil.
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Skopalik S, Hall Barrientos P, Matthews J, Radjenovic A, Mark P, Roditi G, Paul MC. Image-based computational fluid dynamics for estimating pressure drop and fractional flow reserve across iliac artery stenosis: A comparison with in-vivo measurements. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2021; 37:e3437. [PMID: 33449429 DOI: 10.1002/cnm.3437] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 12/07/2020] [Accepted: 01/06/2021] [Indexed: 06/12/2023]
Abstract
Computational Fluid Dynamics (CFD) and time-resolved phase-contrast magnetic resonance imaging (PC-MRI) are potential non-invasive methods for the assessment of the severity of arterial stenoses. Fractional flow reserve (FFR) is the current "gold standard" for determining stenosis severity in the coronary arteries but is an invasive method requiring insertion of a pressure wire. CFD derived FFR (vFFR) is an alternative to traditional catheter derived FFR now available commercially for coronary artery assessment, however, it can potentially be applied to a wider range of vulnerable vessels such as the iliac arteries. In this study CFD simulations are used to assess the ability of vFFR in predicting the stenosis severity in a patient with a stenosis of 77% area reduction (>50% diameter reduction) in the right iliac artery. Variations of vFFR, overall pressure drop and flow split between the vessels were observed by using different boundary conditions. Correlations between boundary condition parameters and resulting flow variables are presented. The study concludes that vFFR has good potential to characterise iliac artery stenotic disease.
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Affiliation(s)
- Simeon Skopalik
- James Watt School of Engineering, University of Glasgow, Glasgow, UK
| | - Pauline Hall Barrientos
- Department of Clinical Physics and Bioengineering, Queen Elizabeth University Hospital, Glasgow, UK
| | | | | | - Patrick Mark
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow, UK
| | - Giles Roditi
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow, UK
| | - Manosh C Paul
- James Watt School of Engineering, University of Glasgow, Glasgow, UK
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Dueñas-Pamplona J, García JG, Sierra-Pallares J, Ferrera C, Agujetas R, López-Mínguez JR. A comprehensive comparison of various patient-specific CFD models of the left atrium for atrial fibrillation patients. Comput Biol Med 2021; 133:104423. [PMID: 33957460 DOI: 10.1016/j.compbiomed.2021.104423] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 04/13/2021] [Accepted: 04/17/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND Recently, advances in medical imaging, segmentation techniques, and high-performance computing have supported the use of patient-specific computational fluid dynamics (CFD) simulations. At present, CFD-compatible atrium geometries can be easily reconstructed from atrium images, providing important insight into the atrial fibrillation (AF) phenomenon, and assistance during therapy selection and surgical procedures. However, the hypothesis assumed for such CFD models should be adequately validated. AIM This work aims to perform an extensive study of the different hypotheses that are commonly assumed when performing atrial simulations for AF patients, as well as to evaluate and compare the range of indices that are usually applied to assess thrombus formation within the left atrium appendage (LAA). METHODS The atrial geometries of two AF patients have been segmented. The resulting geometries have been registered and interpolated to construct a dynamic mesh, which has been employed to compare the rigid and flexible models. Two families of hemodynamic indices have been calculated and compared: wall shear-based and blood age distribution-based. RESULTS The findings of this study illustrate the importance of validating the rigid atrium hypothesis when utilizing an AF CFD model. In particular, the absence of the A-wave contraction does not avoid a certain degree of passive atrial contraction, making the rigid model a poor approximation in some cases. Moreover, a new thrombosis predicting index has been proposed, i.e., M4, which has been shown to predict stasis more effectively than other indicators.
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Affiliation(s)
- Jorge Dueñas-Pamplona
- Departamento de Ingeniería Energética, Escuela Técnica Superior de Ingenieros Industriales, Universidad Politécnica de Madrid, C/ José Gutiérrez Abascal 2, Madrid, Spain.
| | - Javier García García
- Departamento de Ingeniería Energética, Escuela Técnica Superior de Ingenieros Industriales, Universidad Politécnica de Madrid, C/ José Gutiérrez Abascal 2, Madrid, Spain
| | - José Sierra-Pallares
- Departamento de Ingeniería Energética y Fluidomecánica, Escuela de Ingenieros Industriales, Universidad de Valladolid, C/ Paseo Del Cauce 59, Valladolid, Spain
| | - Conrado Ferrera
- Departamento de Ingeniería Mecánica, Energética y de Los Materiales, Escuela de Ingenierías Industriales and Instituto de Computación Científica Avanzada (ICCAEX). Universidad de Extremadura, Avda.de Elvas S/n, 06006, Badajoz, Spain
| | - Rafael Agujetas
- Departamento de Ingeniería Mecánica, Energética y de Los Materiales, Escuela de Ingenierías Industriales and Instituto de Computación Científica Avanzada (ICCAEX). Universidad de Extremadura, Avda.de Elvas S/n, 06006, Badajoz, Spain
| | - José Ramón López-Mínguez
- Sección de Cardiología Intervencionista, Servicio de Cardiología, Hospital Universitario de Badajoz, Avda. de Elvas S/n, 06006, Badajoz, Spain
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Xiong Z, Yuan D, Wang J, Zheng T, Fan Y. Influence of renal artery stenosis morphology on hemodynamics. Comput Methods Biomech Biomed Engin 2021; 24:1294-1301. [PMID: 33565336 DOI: 10.1080/10255842.2021.1883592] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
OBJECTIVE Currently, the clinical classification of the severity of renal artery stenosis (RAS) solely depends on the degree of stenosis. In addition, when the stenosis degree is between 50% and 70%, the clinical strategy is decided based on whether the RAS is hemodynamically significant. In this study, the influence of RAS morphological parameters on hemodynamics was numerically analyzed to provide a theoretical basis for clinical treatment. METHODS Idealized RAS models were established to investigate the hemodynamic effects of the stenosis length, asymmetric stenosis, and direction of the opening of the renal artery. RESULTS The longer the stenosis length, the greater is the ratio of the low time-averaged wall shear stress (WSS) and high oscillatory shear index (OSI) area distal stenosis (when the stenosis area is the same). In addition, asymmetric stenosis leads to a significant increase in the ratio of the renal artery peak systolic velocity (R-PSV) and the abdominal aorta peak systolic velocity (A-PSV) when the stenosis area is 60-70%. Furthermore, the fraction flow reserve (FFR) of the RAS model with 12 mm stenosis length, upward eccentricity and upward direction of renal artery opening was approximately equal to the cumulative value of the influence of different stenosis morphologies on FFR. CONCLUSION An assessment of the severity of RAS should consider the stenosis area and other morphological parameters, including the length and asymmetry of RAS as well as the direction of the opening of renal artery, particularly when the stenosis degree of RAS is between 50% and 70%.
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Affiliation(s)
- Zhuxiang Xiong
- Department of Applied Mechanics, Sichuan University, Chengdu, China
| | - Ding Yuan
- Department of Vascular Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Jiarong Wang
- Department of Vascular Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Tinghui Zheng
- Department of Applied Mechanics, Sichuan University, Chengdu, China
| | - Yubo Fan
- Beijing Advanced Innovation Centre for Biomedical Engineering, Beihang University, Beijing
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Carvalho V, Maia I, Souza A, Ribeiro J, Costa P, Puga H, Teixeira S, Lima RA. In vitro
Biomodels in Stenotic Arteries to Perform Blood Analogues Flow Visualizations and Measurements: A Review. Open Biomed Eng J 2020. [DOI: 10.2174/1874120702014010087] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Cardiovascular diseases are one of the leading causes of death globally and the most common pathological process is atherosclerosis. Over the years, these cardiovascular complications have been extensively studied by applying in vivo, in vitro and numerical methods (in silico). In vivo studies represent more accurately the physiological conditions and provide the most realistic data. Nevertheless, these approaches are expensive, and it is complex to control several physiological variables. Hence, the continuous effort to find reliable alternative methods has been growing. In the last decades, numerical simulations have been widely used to assess the blood flow behavior in stenotic arteries and, consequently, providing insights into the cardiovascular disease condition, its progression and therapeutic optimization. However, it is necessary to ensure its accuracy and reliability by comparing the numerical simulations with clinical and experimental data. For this reason, with the progress of the in vitro flow measurement techniques and rapid prototyping, experimental investigation of hemodynamics has gained widespread attention. The present work reviews state-of-the-art in vitro macro-scale arterial stenotic biomodels for flow measurements, summarizing the different fabrication methods, blood analogues and highlighting advantages and limitations of the most used techniques.
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Liu H, Ou S, Liu P, Xu Y, Gong Y, Xia L, Leng X, Leung TWH, Shi L, Zheng D. Effect of microcirculatory resistance on coronary blood flow and instantaneous wave-free ratio: A computational study. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2020; 196:105632. [PMID: 32615491 DOI: 10.1016/j.cmpb.2020.105632] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 06/21/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND AND OBJECTIVE The instantaneous wave-free ratio (iFR) has been proposed to estimate the hemodynamic severity of atherosclerotic stenosis in coronary arteries. The atherosclerotic stenosis in a proximal coronary artery could change its distal microcirculatory resistance (MR). However, there is a lack of investigation about the effect of MR variation on the blood flow and iFR of stenotic coronary arteries. We aim to investigate the changes of blood flow and iFR caused by distal MR variation. METHODS Four three-dimensional models of coronary arteries were reconstructed from the computed tomography images of two normal cases and two cases with 74.9% and 96.4% (in area) stenoses in a large branch of left anterior descending artery (LAD). Computational fluid dynamics simulation was performed on each model under 6 MR situations: hyperemia as the reference situation, resting when MR was multiplied by 8/3 in all outlet branches, h-one-1.5 and h-one-2 when MR was multiplied by 1.5 and 2.0 in one branch (the stenotic, or the corresponding branch in normal case) of LAD, h-branches-1.5 and h-branches-2 when MR was multiplied by 1.5 and 2.0 in the stenotic/corresponding and its cognate branches. Flow rate and iFR of each outlet branch were then calculated and compared between different MR situations to investigate the effect of MR variation on flow rate and iFR. RESULTS In the 74.9% stenosed and normal cases, referring to the hyperemia situation, the increase of MR in any branch significantly decreased its flow rate and increased its iFR, with limited effect on the flow rate (<3%) and iFR (<0.01) of other branches. However, in the 96.4% stenosed case, the doubled MR in the stenosed branch (h-one-2) significantly increased the flow rate (>10%) and iFR (>0.05) of its cognate branches. CONCLUSION The increase of MR in a normal or mildly stenosed branch of coronary artery decreases its blood flow and increases its iFR, with limited effect on other branches. Whereas, the increase of MR in a severely stenotic large branch could significantly increase the flow velocity and iFR of its cognate branches.
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Affiliation(s)
- Haipeng Liu
- Research Centre for Intelligent Healthcare, Faculty of Health and Life Sciences, Coventry University, Coventry CV1 5FB, UK
| | - Shanxing Ou
- Department of Radiology, General Hospital of Southern Theater Command, PLA, Guangzhou, China
| | - Panli Liu
- Department of Radiology, Guangzhou First People's Hospital, Nansha Hospital, Guangzhou, China
| | - Yuhang Xu
- Research Centre for Intelligent Healthcare, Faculty of Health and Life Sciences, Coventry University, Coventry CV1 5FB, UK
| | - Yinglan Gong
- Department of Biomedical Engineering, Zhejiang University, Hangzhou, China
| | - Ling Xia
- Department of Biomedical Engineering, Zhejiang University, Hangzhou, China
| | - Xinyi Leng
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, China
| | - Thomas Wai Hong Leung
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, China
| | - Lin Shi
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, China.
| | - Dingchang Zheng
- Research Centre for Intelligent Healthcare, Faculty of Health and Life Sciences, Coventry University, Coventry CV1 5FB, UK.
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