1
|
Chen X, Qiu F, Wang W, Qi Z, Lyu D, Xue K, Sun L, Song D. Vector flow mapping analysis of left ventricular vortex performance in type 2 diabetic patients with early chronic kidney disease. BMC Cardiovasc Disord 2023; 23:434. [PMID: 37658336 PMCID: PMC10474629 DOI: 10.1186/s12872-023-03474-7] [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: 03/20/2023] [Accepted: 08/25/2023] [Indexed: 09/03/2023] Open
Abstract
BACKGROUND Diabetes is the leading cause of chronic kidney disease (CKD) and contributes to an elevated incidence of diastolic dysfunction in the early stages of CKD. Intracardiac vortex is a novel hemodynamic index for perceiving cardiac status. Here, we visualized left ventricular (LV) vortex characteristics using vector flow mapping (VFM) in type 2 diabetic patients with early CKD. METHODS This cross-sectional study included 67 controls and 89 type 2 diabetic patients with stages 2-3a CKD. All subjects underwent transthoracic echocardiographic examination. LV anterior vortex during early diastole (E-vortex), atrial contraction (A-vortex) and systole (S-vortex) were assessed using VFM in the apical long-axis view. Its relation to glycemia or LV filling echocardiographic parameters were further analyzed using correlation analysis. RESULTS Type 2 diabetic patients with early CKD had a small area (439.94 ± 132.37 mm2 vs. 381.66 ± 136.85 mm2, P = 0.008) and weak circulation (0.0226 ± 0.0079 m2/s vs. 0.0195 ± 0.0070 m2/s, P = 0.013) of E-vortex, but a large area (281.52 ± 137.27 mm2 vs. 514.83 ± 160.33 mm2, P ˂ 0.001) and intense circulation (0.0149 ± 0.0069 m2/s vs. 0.0250 ± 0.0067 m2/s, P < 0.001) of A-vortex compared to controls. CKD patients with poorly controlled hyperglycemia had stronger A-vortex (area: 479.06 ± 146.78 mm2 vs. 559.96 ± 159.27 mm2, P = 0.015; circulation: 0.0221 ± 0.0058 m2/s vs. 0.0275 ± 0.0064 m2/s, P < 0.001) and S-vortex (area: 524.21 ± 165.52 mm2 vs. 607.87 ± 185.33 mm2, P = 0.029; circulation: 0.0174 ± 0.0072 m2/s vs. 0.0213 ± 0.0074 m2/s, P = 0.015), and a longer relative duration of S-vortex (0.7436 ± 0.0772 vs. 0.7845 ± 0.0752, P = 0.013) than those who had well-controlled hyperglycemia. Glycemia, and E/A (a LV filling parameter) were respectively found to had close correlation to the features of A-vortex and S-vortex (all P < 0.05). CONCLUSIONS Abnormal LV vortices were detected in type 2 diabetic patients with early CKD using VFM, especially in those who neglected hyperglycemic control. LV vortex might be a promising parameter to slow or halt the hyperglycemia-induced diastolic dysfunction in early CKD.
Collapse
Affiliation(s)
- Xiaoxue Chen
- Department of Ultrasound, First Hospital of Qinhuangdao, Hebei Medical University, No.258, Wenhua Road, Qinhuangdao, 066000, Hebei, China
- Hebei Key Laboratory of Vascular Homeostasis and Hebei Collaborative Innovation Center for Cardio- cerebrovascular Disease, No. 215, Hepingxi Road, Shijiazhuang, 050000, Hebei, China
| | - Fang Qiu
- Department of cardiology, First Hospital of Qinhuangdao, Hebei Medical University, No.258, Wenhua Road, Qinhuangdao, 066000, Hebei, China
| | - Wei Wang
- Department of Cardiac Ultrasound, Second Hospital of Hebei Medical University, 215 Hepingxi Road, Shijiazhuang, 050000, Hebei, China
| | - Zhengqin Qi
- Department of Ultrasound, First Hospital of Qinhuangdao, Hebei Medical University, No.258, Wenhua Road, Qinhuangdao, 066000, Hebei, China
| | - Damin Lyu
- Department of Ultrasound, First Hospital of Qinhuangdao, Hebei Medical University, No.258, Wenhua Road, Qinhuangdao, 066000, Hebei, China
| | - Kun Xue
- Department of Ultrasound, First Hospital of Qinhuangdao, Hebei Medical University, No.258, Wenhua Road, Qinhuangdao, 066000, Hebei, China
| | - Lijuan Sun
- Department of Ultrasound, First Hospital of Qinhuangdao, Hebei Medical University, No.258, Wenhua Road, Qinhuangdao, 066000, Hebei, China
| | - Degang Song
- Hebei Key Laboratory of Vascular Homeostasis and Hebei Collaborative Innovation Center for Cardio- cerebrovascular Disease, No. 215, Hepingxi Road, Shijiazhuang, 050000, Hebei, China.
- Department of neurology, First Hospital of Qinhuangdao, Hebei Medical University, No.258, Wenhua Road, Qinhuangdao, 066000, Hebei, China.
| |
Collapse
|
2
|
Chan JSK, Lau DHH, Fan Y, Lee APW. Fragmented Vortex in Heart Failure With Reduced Ejection Fraction: A Prospective Vector Flow Mapping Study. ULTRASOUND IN MEDICINE & BIOLOGY 2023; 49:982-988. [PMID: 36581516 DOI: 10.1016/j.ultrasmedbio.2022.12.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 11/29/2022] [Accepted: 12/03/2022] [Indexed: 06/17/2023]
Abstract
OBJECTIVE Heart failure with reduced ejection fraction (HFrEF) is associated with structural and functional left ventricular changes. We compared intracardiac vortices between patients with HFrEF and normal participants using echocardiographic vector flow mapping, a novel intracardiac vortex analysis technology. METHODS Transthoracic echocardiography was performed on 20 patients with HFrEF (age: 61 ± 15 y, 15 men) and 20 normal participants (age: 59 ± 12 y, 12 men) age- and sex-balanced at the cohort level. Systolic and diastolic energy loss, area (indexed by left ventricular end-diastolic diameter), circulation (reflects vortex strength) and relative positions of the largest vortex during systole (S-vortex), early (E-vortex) and late (A-vortex) diastole and maximal number of vortices in a single frame (MNV) were assessed. DISCUSSION Patients with HFrEF had disproportionately sized vortices with smaller indexed vortex areas (p < 0.0001), and more fragmented vortices with higher MNV during both systole (p = 0.030) and diastole (p < 0.0001). These accompanied higher diastolic energy loss (p = 0.001). Additionally, the E-vortex (p = 0.002) and A-vortex (p < 0.0001) were more apically positioned, and the S-vortex was weaker (p = 0.033) in patients with HFrEF. More severe fragmentation (higher MNV) correlated with worse energy efficiency (higher energy loss). CONCLUSION Patients with HFrEF had more fragmented intracardiac vortices and lower energy efficiency predominantly during diastole.
Collapse
Affiliation(s)
- Jeffrey Shi Kai Chan
- Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, China; Laboratory of Cardiac Imaging and 3D Printing, Li Ka Shing Institute of Health Sciences, Hong Kong, China
| | - Dawnie Ho Hei Lau
- Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, China; Laboratory of Cardiac Imaging and 3D Printing, Li Ka Shing Institute of Health Sciences, Hong Kong, China
| | - Yiting Fan
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Xu Hui District, Shanghai, China
| | - Alex Pui-Wai Lee
- Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, China; Laboratory of Cardiac Imaging and 3D Printing, Li Ka Shing Institute of Health Sciences, Hong Kong, China.
| |
Collapse
|
3
|
Li C, Li K, Wang F, Rao L. Amount of dissipative energy loss when assessing left ventricular dysfunction in female patients with systemic lupus erythematosus. Heart Vessels 2022; 37:1175-1183. [PMID: 34982203 DOI: 10.1007/s00380-021-02017-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 12/24/2021] [Indexed: 02/08/2023]
Abstract
Systemic lupus erythematosus (SLE) is associated with an increased risk of cardiovascular disease. The purpose of the current study was to explore the amount of energy loss (EL) using vector flow mapping (VFM) in the detection of early stage left ventricular (LV) dysfunction among patients with SLE. Eighty-nine patients with SLE and fifty-six healthy controls were enrolled. SLE patients were further divided into inactive (SLEDAI ≤ 4, n = 43) and active (SLEDAI ≥ 5, n = 46) subgroups. A prosound F75 echocardiography machine was used for echocardiographic examination. Intra-cardiac flow images were analysed by a VFM workstation. Compared with the healthy group, the inactive SLE group had increased diastolic EL values (38.05 mW/m vs. 33.02 mW/m, p = 0.010). However, the systolic EL values were comparable between the inactive SLE group and the control group (26.07mW/m vs 23.15 mW/m, p = 0.105). The active SLE group exhibited significantly higher diastolic (104.13 mW/m vs 33.02 mW/m, p < 0.001) and systolic (48.83 mW/m vs 23.15 mW/m, p < 0.001) EL values than the control group. The most notable correlation was observed between the values of the diastolic EL and SLEDAI in the inactive SLE group (r = 0.633, p < 0.001) and in the active SLE group (r = 0.824, p < 0.001). LV-dissipative EL assessed by using VFM is useful and feasible for estimating lesions of LV systolic and diastolic function in active SLE patients with preserved left ventricular ejection fraction. Increased disease activity may lead to increased risk of LV dysfunction.
Collapse
Affiliation(s)
- Chunmei Li
- Department of Cardiology, West China Hospital of Sichuan University, 37 Guo Xue Xiang, Chengdu, 610041, China
| | - Kun Li
- Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, 610041, China
| | - Fang Wang
- Department of Cardiology, West China Hospital of Sichuan University, 37 Guo Xue Xiang, Chengdu, 610041, China
| | - Li Rao
- Department of Cardiology, West China Hospital of Sichuan University, 37 Guo Xue Xiang, Chengdu, 610041, China.
| |
Collapse
|
4
|
Age-Related Changes in Left Ventricular Vortex Formation and Flow Energetics. J Clin Med 2021; 10:jcm10163619. [PMID: 34441914 PMCID: PMC8397127 DOI: 10.3390/jcm10163619] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 07/29/2021] [Accepted: 08/03/2021] [Indexed: 11/26/2022] Open
Abstract
Analysis of the cardiac vortex has been used for a deeper understanding of the pathophysiology in heart diseases. However, physiological changes of the cardiac vortex with normal aging are incompletely defined. Vector flow mapping (VFM) is a novel echocardiographic technique based on Doppler and speckle tracking for analysis of the cardiac vortex. Transthoracic echocardiography and VFM analysis were performed in 100 healthy adults (33 men; age = 18–67 years). The intracardiac flow was assessed throughout the cardiac cycle. The size (cross-sectional area) and circulation (equivalent to the integral of normal component of vorticity) of the largest vortices in systole (S-vortex), early diastole (E-vortex), and late diastole (A-vortex) were measured. Peak energy loss (EL) was calculated from information of the velocity vector of intracardiac flow in systole and diastole. With normal aging, the circulation (p = 0.049) of the E-vortex decreased, while that of the A-vortex increased (both p < 0.001). E-vortex circulation correlated directly to e’ (p = 0.003), A-vortex circulation correlated directly to A and a’ (both p < 0.001), and S-vortex circulation correlated directly to s’ (p = 0.032). Despite changes in vortex patterns, energy loss was not significantly different in older individuals. Normal aging is associated with altered intracardiac vortex patterns throughout the cardiac cycle, with the late-diastolic A-vortex becoming physiologically more dominant. Maintained energy efficiency accompanies changes in vortex patterns in aging hearts.
Collapse
|
5
|
Avesani M, Degrelle B, Di Salvo G, Thambo JB, Iriart X. Vector flow mapping: A review from theory to practice. Echocardiography 2021; 38:1405-1413. [PMID: 34259359 DOI: 10.1111/echo.15154] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 06/19/2021] [Accepted: 07/01/2021] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND The interest in intra-cardiac blood flow analysis is rapidly growing, and it has encouraged the development of different non-invasive imaging techniques. Among these, Vector Flow Mapping (VFM), combing Color-Doppler imaging and speckle tracking data, seems to be a promising approach, feasible in adult and children population. AIM OF THE REVIEW The aim of this review is to give a historical perspective on the development of VFM method and a summary of the current algorithms and parameters potentially evaluable. Then, we will present the current state-of-the-art of VFM with an overview of clinical studies and applications of this technique.
Collapse
Affiliation(s)
- Martina Avesani
- Department of Pediatric and Adult Congenital Cardiology, Bordeaux University Hospital (CHU), Pessac, France.,Department of Women's and Children's Health, University of Padua, Padua, Italy
| | - Bastien Degrelle
- Department of Pediatric and Adult Congenital Cardiology, Bordeaux University Hospital (CHU), Pessac, France
| | - Giovanni Di Salvo
- Department of Women's and Children's Health, University of Padua, Padua, Italy
| | - Jean-Benoit Thambo
- Department of Pediatric and Adult Congenital Cardiology, Bordeaux University Hospital (CHU), Pessac, France.,Electrophysiology and Heart Modeling Institute, IHU Liryc, Fondation Bordeaux Université, Bordeaux, France.,Centre de recherche Cardio-Thoracique de Bordeaux, INSERM, Bordeaux, France
| | - Xavier Iriart
- Department of Pediatric and Adult Congenital Cardiology, Bordeaux University Hospital (CHU), Pessac, France.,Electrophysiology and Heart Modeling Institute, IHU Liryc, Fondation Bordeaux Université, Bordeaux, France.,Centre de recherche Cardio-Thoracique de Bordeaux, INSERM, Bordeaux, France
| |
Collapse
|
6
|
Futami S, Ishikawa J, Maeda T, Kawano M, Sakurayama C, Harada K. Factors contributing to energy loss in left ventricle during diastolic and systolic phases in elderly patients. Echocardiography 2020; 38:72-80. [PMID: 33220089 DOI: 10.1111/echo.14930] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 10/21/2020] [Accepted: 10/27/2020] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND The change of left ventricular function deteriorated with age because of gradual increases of blood pressure may result in increased energy loss (EL) in left ventricle (LV). The present study investigated EL in LV among hypertensive elderly patients and examined factors contributing to EL. METHODS A single-center retrospective study was performed on elderly hypertensive outpatients (≥65 years) who underwent echocardiography (N = 105). EL in the LV was measured using a vector flow mapping system, and factors affecting peak EL during the early-diastolic phase (ED-EL), late-diastolic phase (LD-EL), and systolic phase (Sys-EL) were evaluated. RESULT Mean age was 79.9 ± 6.4 years (male 43%). Mean ED-EL, LD-EL, and Sys-EL were 42.1 ± 46.7, 75.6 ± 60.2, and 40.4 ± 40.2 mJ/N/s. In a stepwise regression analysis, the E/e'(lateral) (unstandardized B = 0.005, 95%CI -0.03 to 0.007, standardized β = 0.434, P < .001) was identified as factors affecting ED-EL. The factors affecting LD-EL were E/A ratio (B = -0.122, 95%CI -0.176 to -0.068, β = -0.470, P < .001) and time velocity integral (TVI) in LVOT (unstandardized B = 0.002, 95%CI 0.000 to 0.004, β = 0.247, P = .021). The factors influencing Sys-EL were TVI in LVOT (B = 0.002, 95%CI 0.001 to 0.004, β = 0.390, P < .001), E/A ratio (B = -0.054, 95%CI -0.093 to -0.015, β = -0.258, P = .008), left ventricular outflow tract (LVOT) diameter (B = -0.006, 95%CI -0.010 to -0.002, β = -0.307, P = .006), and left ventricular mass index (B = 0.000, 95%CI 0.000 to 0.001, β = 0.208, P = .039). CONCLUSION Peak EL in the LV was higher during diastolic phase than systolic phase among elderly hypertensive patients. Peak EL both during late-diastolic phase and systolic phase was affected by systolic blood flow in LVOT and LV transmitral flow pattern.
Collapse
Affiliation(s)
- Shutaro Futami
- Department of Cardiology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan.,Department of Hematology, Oncology and Cardiovascular Medicine, Kyushu University Hospital, Fukuoka, Japan
| | - Joji Ishikawa
- Department of Cardiology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan
| | - Teppei Maeda
- Department of Clinical Laboratory, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan
| | - Masuyo Kawano
- Department of Clinical Laboratory, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan
| | - Chieko Sakurayama
- Department of Clinical Laboratory, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan
| | - Kazumasa Harada
- Department of Cardiology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan
| |
Collapse
|
7
|
Chen X, Wang Y, Wang W, Yuan L, Qi Z, Song D. Assessment of left ventricular energy loss using vector flow mapping in patients with stages 1-3 chronic kidney disease. BMC Cardiovasc Disord 2020; 20:355. [PMID: 32741356 PMCID: PMC7397582 DOI: 10.1186/s12872-020-01640-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 07/23/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Patients with chronic kidney disease (CKD) experience abnormality of intracardiac blood flow status during early-stages of disease. Left ventricular energy loss (EL) derived from vector flow mapping (VFM) represents fluid energy lost as heat in left ventricle and had been used to detect intracardiac blood flow efficiency. We aimed to evaluate the left ventricular EL in stage 1-3 CKD patients, and explored whether hypertension, a main cardiovascular risk, deteriorate the abnormality of intracardiac blood flow status. METHODS Transthoracic echocardiography was performed in 41 controls and 48 patients with stages 1-3 CKD. CKD patients consisted a subgroup with no hypertension, a subgroup with well-controlled hypertension and a subgroup with poorly controlled hypertension. The EL were calculated in the left ventricle using VFM analysis from the apical 3-chamber view. Furthermore, the correlation and stepwise multiple regression analysis were used to explore the potential independent predictors of left ventricular EL. RESULTS Compared with controls, stage 1-3 CKD patients showed increased left ventricular EL during total diastole, late diastole, total systole, isovolumic contraction and ejection. CKD patients with poorly controlled hypertension had higher left ventricular EL compared to the other CKD subgroups. Additionally, the ratio of mitral early filling wave peak velocity and early mitral annular peak velocity on septal side, mitral early filling wave peak velocity, and left ventricular mass index were independent predictors of the diastolic EL; whereas systolic blood pressure and left ventricular mass index were independent predictors of the systolic EL. CONCLUSIONS Left ventricular EL was a useful echocardiographic parameter to evaluate the impaired intracardiac blood flow efficiency in patients with stages 1-3 CKD. Hypertension was a crucial contributor for intracardiac blood flow abnormality. This study might provide valuable clinical data to discern cardiac dysfunction and reduce the cardiovascular risk in early-stage CKD.
Collapse
Affiliation(s)
- Xiaoxue Chen
- Department of Cardiac Ultrasound, Second Hospital of Hebei Medical University, 215 Hepingxi Road, Shijiazhuang, 050000, Hebei, China
| | - Yueheng Wang
- Department of Cardiac Ultrasound, Second Hospital of Hebei Medical University, 215 Hepingxi Road, Shijiazhuang, 050000, Hebei, China.
| | - Wei Wang
- Department of Cardiac Ultrasound, Second Hospital of Hebei Medical University, 215 Hepingxi Road, Shijiazhuang, 050000, Hebei, China
| | - Lijun Yuan
- Department of Cardiac Ultrasound, Second Hospital of Hebei Medical University, 215 Hepingxi Road, Shijiazhuang, 050000, Hebei, China
| | - Zhengqin Qi
- First Hospital of Qinhuangdao, Qinhuangdao, 066000, Hebei, China
| | - Degang Song
- First Hospital of Qinhuangdao, Qinhuangdao, 066000, Hebei, China
| |
Collapse
|
8
|
Liu R, Cui C, Li Y, Qiu Z, Hu Y, Wang Y, Cui M, Yin S, Liu L. Analysis of left ventricular diastolic energy loss in patients with aortic stenosis with preserved ejection fraction by using vector flow mapping. Echocardiography 2019; 36:2216-2226. [PMID: 31876982 DOI: 10.1111/echo.14555] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Ruijie Liu
- Department of Ultrasound Henan Provincial People’s Hospital Heart Center Fuwai Central China Cardiovascular Hospital People’s Hospital of Zhengzhou University Zhengzhou China
| | - Cunying Cui
- Department of Ultrasound Henan Provincial People’s Hospital Heart Center Fuwai Central China Cardiovascular Hospital People’s Hospital of Zhengzhou University Zhengzhou China
| | - Yanan Li
- Department of Ultrasound Henan Provincial People’s Hospital Heart Center Fuwai Central China Cardiovascular Hospital People’s Hospital of Zhengzhou University Zhengzhou China
| | - Zhaoying Qiu
- Department of Ultrasound Henan Provincial People’s Hospital Heart Center Fuwai Central China Cardiovascular Hospital People’s Hospital of Zhengzhou University Zhengzhou China
| | - Yanbin Hu
- Department of Ultrasound Henan Provincial People’s Hospital Heart Center Fuwai Central China Cardiovascular Hospital People’s Hospital of Zhengzhou University Zhengzhou China
| | - Ying Wang
- Department of Ultrasound Henan Provincial People’s Hospital Heart Center Fuwai Central China Cardiovascular Hospital People’s Hospital of Zhengzhou University Zhengzhou China
| | - Mingxia Cui
- Department of Ultrasound Henan Provincial People’s Hospital Heart Center Fuwai Central China Cardiovascular Hospital People’s Hospital of Zhengzhou University Zhengzhou China
| | - Shanshan Yin
- Henan Academy of Medical Sciences Zhengzhou China
| | - Lin Liu
- Department of Ultrasound Henan Provincial People’s Hospital Heart Center Fuwai Central China Cardiovascular Hospital People’s Hospital of Zhengzhou University Zhengzhou China
| |
Collapse
|