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Nardone M, Foster M, O'Brien MW, Coovadia Y, Xie S, Usselman CW, Kimmerly DS, Taylor CE, Millar PJ. Sympathetic determinants of resting blood pressure in males and females. Am J Physiol Heart Circ Physiol 2024; 326:H612-H622. [PMID: 38214907 DOI: 10.1152/ajpheart.00497.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 01/08/2024] [Accepted: 01/08/2024] [Indexed: 01/13/2024]
Abstract
Discharge of postganglionic muscle sympathetic nerve activity (MSNA) is related poorly to blood pressure (BP) in adults. Whether neural measurements beyond the prevailing level of MSNA can account for interindividual differences in BP remains unclear. The current study sought to evaluate the relative contributions of sympathetic-BP transduction and sympathetic baroreflex gain on resting BP in young adults. Data were analyzed from 191 (77 females) young adults (18-39 years) who underwent continuous measurement of beat-to-beat BP (finger photoplethysmography), heart rate (electrocardiography), and fibular nerve MSNA (microneurography). Linear regression analyses were computed to determine associations between sympathetic-BP transduction (signal-averaging) or sympathetic baroreflex gain (threshold technique) and resting BP, before and after controlling for age, body mass index, and MSNA burst frequency. K-mean clustering was used to explore sympathetic phenotypes of BP control and consequential influence on resting BP. Sympathetic-BP transduction was unrelated to BP in males or females (both R2 < 0.01; P > 0.67). Sympathetic baroreflex gain was positively associated with BP in males (R2 = 0.09, P < 0.01), but not in females (R2 < 0.01; P = 0.80), before and after controlling for age, body mass index, and MSNA burst frequency. K-means clustering identified a subset of participants with average resting MSNA, yet lower sympathetic-BP transduction and lower sympathetic baroreflex gain. This distinct subgroup presented with elevated BP in males (P < 0.02), but not in females (P = 0.10). Sympathetic-BP transduction is unrelated to resting BP, while the association between sympathetic baroreflex gain and resting BP in males reveals important sex differences in the sympathetic determination of resting BP.NEW & NOTEWORTHY In a sample of 191 normotensive young adults, we confirm that resting muscle sympathetic nerve activity is a poor predictor of resting blood pressure and now demonstrate that sympathetic baroreflex gain is associated with resting blood pressure in males but not females. In contrast, signal-averaged measures of sympathetic-blood pressure transduction are unrelated to resting blood pressure. These findings highlight sex differences in the neural regulation of blood pressure.
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Affiliation(s)
- Massimo Nardone
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Monique Foster
- School of Health Sciences, Western Sydney University, Sydney, New South Wales, Australia
| | - Myles W O'Brien
- Division of Kinesiology, School of Health and Human Performance, Faculty of Health, Dalhousie University, Halifax, Nova Scotia, Canada
- School of Physiotherapy (Faculty of Health) and Division of Geriatric Medicine (Faculty of Medicine), Dalhousie University, Halifax, Nova Scotia, Canada
| | - Yasmine Coovadia
- Cardiovascular Health and Autonomic Regulation Laboratory, Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada
| | - Shengkun Xie
- Global Management Studies, Ted Rogers School of Management, Toronto Metropolitan University, Toronto, Ontario, Canada
| | - Charlotte W Usselman
- Cardiovascular Health and Autonomic Regulation Laboratory, Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada
| | - Derek S Kimmerly
- Division of Kinesiology, School of Health and Human Performance, Faculty of Health, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Chloe E Taylor
- School of Health Sciences, Western Sydney University, Sydney, New South Wales, Australia
| | - Philip J Millar
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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Ferrario CM, Saha A, VonCannon JL, Meredith WJ, Ahmad S. Does the Naked Emperor Parable Apply to Current Perceptions of the Contribution of Renin Angiotensin System Inhibition in Hypertension? Curr Hypertens Rep 2022; 24:709-721. [PMID: 36272015 DOI: 10.1007/s11906-022-01229-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/17/2022] [Indexed: 01/31/2023]
Abstract
PURPOSE OF REVIEW To address contemporary hypertension challenges, a critical reexamination of therapeutic accomplishments using angiotensin converting enzyme inhibitors and angiotensin II receptor blockers, and a greater appreciation of evidence-based shortcomings from randomized clinical trials are fundamental in accelerating future progress. RECENT FINDINGS Medications targeting angiotensin II mechanism of action are essential for managing primary hypertension, type 2 diabetes, heart failure, and chronic kidney disease. While the ability of angiotensin converting enzyme inhibitors and angiotensin II receptor blockers to control blood pressure is undisputed, practitioners, hypertension specialists, and researchers hold low awareness of these drugs' limitations in preventing or reducing the risk of cardiovascular events. Biases in interpreting gained knowledge from data obtained in randomized clinical trials include a pervasive emphasis on using relative risk reduction over absolute risk reduction. Furthermore, recommendations for clinical practice in international hypertension guidelines fail to address the significance of a residual risk several orders of magnitude greater than the benefits. We analyze the limitations of the clinical trials that have led to current recommended treatment guidelines. We define and quantify the magnitude of the residual risk in published hypertension trials and explore how activation of alternate compensatory bioprocessing components within the renin angiotensin system bypass the ability of angiotensin converting enzyme inhibitors and angiotensin II receptor blockers to achieve a significant reduction in total and cardiovascular deaths. We complete this presentation by outlining the current incipient but promising potential of immunotherapy to block angiotensin II pathology alone or possibly in combination with other antihypertensive drugs. A full appreciation of the magnitude of the residual risk associated with current renin angiotensin system-based therapies constitutes a vital underpinning for seeking new molecular approaches to halt or even reverse the cardiovascular complications of primary hypertension and encourage investigating a new generation of ACE inhibitors and ARBs with increased capacity to reach the intracellular compartments at which Ang II can be generated.
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Affiliation(s)
- Carlos M Ferrario
- Laboratory of Translational Hypertension and Vascular Research, Department of General Surgery, Wake Forest School of Medicine, Medical Center Blvd, Atrium Health Wake Forest Baptist, Winston Salem, NC, 27157, USA.
| | - Amit Saha
- Department of Anesthesiology, Wake Forest School of Medicine, Medical Center Blvd, Atrium Health Wake Forest Baptist, Winston Salem, NC, 27157, USA
| | - Jessica L VonCannon
- Laboratory of Translational Hypertension and Vascular Research, Department of General Surgery, Wake Forest School of Medicine, Medical Center Blvd, Atrium Health Wake Forest Baptist, Winston Salem, NC, 27157, USA
| | - Wayne J Meredith
- Laboratory of Translational Hypertension and Vascular Research, Department of General Surgery, Wake Forest School of Medicine, Medical Center Blvd, Atrium Health Wake Forest Baptist, Winston Salem, NC, 27157, USA
| | - Sarfaraz Ahmad
- Laboratory of Translational Hypertension and Vascular Research, Department of General Surgery, Wake Forest School of Medicine, Medical Center Blvd, Atrium Health Wake Forest Baptist, Winston Salem, NC, 27157, USA
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Kobetic MD, Burchell AE, Ratcliffe LEK, Neumann S, Adams ZH, Nolan R, Nightingale AK, Paton JFR, Hart EC. Sympathetic-transduction in untreated hypertension. J Hum Hypertens 2022; 36:24-31. [PMID: 34453103 PMCID: PMC8766277 DOI: 10.1038/s41371-021-00578-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 04/28/2021] [Accepted: 07/07/2021] [Indexed: 01/31/2023]
Abstract
Transduction of muscle sympathetic nerve activity (MSNA) into vascular tone varies with age and sex. Older normotensive men have reduced sympathetic transduction so that a given level of MSNA causes less arteriole vasoconstriction. Whether sympathetic transduction is altered in hypertension (HTN) is not known. We investigated whether sympathetic transduction is impaired in untreated hypertensive men compared to normotensive controls. Eight untreated hypertensive men and 10 normotensive men (age 50 ± 15 years vs. 45 ± 12 years (mean ± SD); p = 0.19, body mass index (BMI) 24.7 ± 2.7 kg/m2 vs. 26.0 ± 4.2 kg/m2; p = 0.21) were recruited. MSNA was recorded from the peroneal nerve using microneurography; beat-to-beat blood pressure (BP; Finapres) and heart rate (ECG) were recorded simultaneously at rest for 10 min. Sympathetic-transduction was quantified using a previously described method. The relationship between MSNA burst area and subsequent diastolic BP was measured for each participant with the slope of the regression indicating sympathetic transduction. MSNA was higher in the hypertensive group compared to normotensives (73 ± 17 bursts/100 heartbeats vs. 49 ± 19 bursts/100 heart bursts; p = 0.007). Sympathetic-transduction was lower in the hypertensive versus normotensive group (0.04%/mmHg/s vs. 0.11%/mmHg/s, respectively; R = 0.622; p = 0.006). In summary, hypertensive men had lower sympathetic transduction compared to normotensive individuals suggesting that higher levels of MSNA are needed to cause the same level of vasoconstrictor tone.
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Affiliation(s)
- Matthew D. Kobetic
- grid.5337.20000 0004 1936 7603School of Physiology, Pharmacology, and Neuroscience, Clinical Research and Imaging Centre, University of Bristol, Bristol, UK
| | - Amy E. Burchell
- grid.5337.20000 0004 1936 7603Cardionomics Research Group, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, University of Bristol, Bristol, UK
| | - Laura E. K. Ratcliffe
- grid.415953.f0000 0004 0400 1537Department of Nephrology, Lister Hospital, East and North Hertfordshire NHS Trust, Hertfordshire, UK
| | - Sandra Neumann
- grid.5337.20000 0004 1936 7603School of Physiology, Pharmacology, and Neuroscience, Clinical Research and Imaging Centre, University of Bristol, Bristol, UK ,grid.5337.20000 0004 1936 7603Cardionomics Research Group, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, University of Bristol, Bristol, UK
| | - Zoe H. Adams
- grid.5337.20000 0004 1936 7603School of Physiology, Pharmacology, and Neuroscience, Clinical Research and Imaging Centre, University of Bristol, Bristol, UK ,grid.5337.20000 0004 1936 7603Cardionomics Research Group, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, University of Bristol, Bristol, UK
| | - Regina Nolan
- grid.5337.20000 0004 1936 7603Cardionomics Research Group, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, University of Bristol, Bristol, UK
| | - Angus K. Nightingale
- grid.5337.20000 0004 1936 7603School of Physiology, Pharmacology, and Neuroscience, Clinical Research and Imaging Centre, University of Bristol, Bristol, UK ,grid.5337.20000 0004 1936 7603Cardionomics Research Group, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, University of Bristol, Bristol, UK
| | - Julian F. R. Paton
- grid.5337.20000 0004 1936 7603School of Physiology, Pharmacology, and Neuroscience, Clinical Research and Imaging Centre, University of Bristol, Bristol, UK ,grid.5337.20000 0004 1936 7603Cardionomics Research Group, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, University of Bristol, Bristol, UK
| | - Emma C. Hart
- grid.5337.20000 0004 1936 7603School of Physiology, Pharmacology, and Neuroscience, Clinical Research and Imaging Centre, University of Bristol, Bristol, UK ,grid.5337.20000 0004 1936 7603Cardionomics Research Group, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, University of Bristol, Bristol, UK
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Osborn JW, Tyshynsky R, Vulchanova L. Function of Renal Nerves in Kidney Physiology and Pathophysiology. Annu Rev Physiol 2021; 83:429-450. [PMID: 33566672 DOI: 10.1146/annurev-physiol-031620-091656] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Renal sympathetic (efferent) nerves play an important role in the regulation of renal function, including glomerular filtration, sodium reabsorption, and renin release. The kidney is also innervated by sensory (afferent) nerves that relay information to the brain to modulate sympathetic outflow. Hypertension and other cardiometabolic diseases are linked to overactivity of renal sympathetic and sensory nerves, but our mechanistic understanding of these relationships is limited. Clinical trials of catheter-based renal nerve ablation to treat hypertension have yielded promising results. Therefore, a greater understanding of how renal nerves control the kidney under physiological and pathophysiological conditions is needed. In this review, we provide an overview of the current knowledge of the anatomy of efferent and afferent renal nerves and their functions in normal and pathophysiological conditions. We also suggest further avenues of research for development of novel therapies targeting the renal nerves.
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Affiliation(s)
- John W Osborn
- Department of Surgery, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA;
| | - Roman Tyshynsky
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Lucy Vulchanova
- Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455, USA
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Guyenet PG, Stornetta RL, Souza GMPR, Abbott SBG, Brooks VL. Neuronal Networks in Hypertension: Recent Advances. Hypertension 2020; 76:300-311. [PMID: 32594802 DOI: 10.1161/hypertensionaha.120.14521] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Neurogenic hypertension is associated with excessive sympathetic nerve activity to the kidneys and portions of the cardiovascular system. Here we examine the brain regions that cause heightened sympathetic nerve activity in animal models of neurogenic hypertension, and we discuss the triggers responsible for the changes in neuronal activity within these regions. We highlight the limitations of the evidence and, whenever possible, we briefly address the pertinence of the findings to human hypertension. The arterial baroreflex reduces arterial blood pressure variability and contributes to the arterial blood pressure set point. This set point can also be elevated by a newly described cerebral blood flow-dependent and astrocyte-mediated sympathetic reflex. Both reflexes converge on the presympathetic neurons of the rostral medulla oblongata, and both are plausible causes of neurogenic hypertension. Sensory afferent dysfunction (reduced baroreceptor activity, increased renal, or carotid body afferent) contributes to many forms of neurogenic hypertension. Neurogenic hypertension can also result from activation of brain nuclei or sensory afferents by excess circulating hormones (leptin, insulin, Ang II [angiotensin II]) or sodium. Leptin raises blood vessel sympathetic nerve activity by activating the carotid bodies and subsets of arcuate neurons. Ang II works in the lamina terminalis and probably throughout the brain stem and hypothalamus. Sodium is sensed primarily in the lamina terminalis. Regardless of its cause, the excess sympathetic nerve activity is mediated to some extent by activation of presympathetic neurons located in the rostral ventrolateral medulla or the paraventricular nucleus of the hypothalamus. Increased activity of the orexinergic neurons also contributes to hypertension in selected models.
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Affiliation(s)
- Patrice G Guyenet
- From the Department of Pharmacology, University of Virginia, Charlottesville (P.G.G., R.L.S., G.M.P.R.S., S.B.G.A.)
| | - Ruth L Stornetta
- From the Department of Pharmacology, University of Virginia, Charlottesville (P.G.G., R.L.S., G.M.P.R.S., S.B.G.A.)
| | - George M P R Souza
- From the Department of Pharmacology, University of Virginia, Charlottesville (P.G.G., R.L.S., G.M.P.R.S., S.B.G.A.)
| | - Stephen B G Abbott
- From the Department of Pharmacology, University of Virginia, Charlottesville (P.G.G., R.L.S., G.M.P.R.S., S.B.G.A.)
| | - Virginia L Brooks
- Department of Chemical Physiology and Biochemistry, Oregon Health & Sciences University, Portland (V.L.B.)
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Alula KM, Biltz R, Xu H, Garver H, Laimon-Thomson EL, Fink GD, Galligan JJ. Effects of high-fat diet on sympathetic neurotransmission in mesenteric arteries from Dahl salt-sensitive rat. Auton Neurosci 2019; 222:102599. [PMID: 31731103 DOI: 10.1016/j.autneu.2019.102599] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 10/18/2019] [Accepted: 10/29/2019] [Indexed: 12/19/2022]
Abstract
Obesity hypertension is driven by sympathetic neurotransmission to the heart and blood vessels. We tested the hypothesis that high-fat diet (HFD)-induced hypertension is driven by sympathetic neurotransmission to mesenteric arteries (MA) in male but not female Dahl salt-sensitive (Dahl ss) rat. Rats were fed a control diet (CD; 10 kcal% from fat) or HFD (60 kcal% from fat) beginning at 3 weeks (wk) of age; measurements were made at 10-, 17- and 24-wk. Body weight increased with HFD, age and sex. Mean arterial pressure (MAP) was higher in HFD versus CD rats from both sexes at 17- and 24-wk. MA constriction measured using pressure myography, and electrical field stimulation (EFS, 0.2-30 Hz) was greater in HFD versus CD in males at 17-wk; this was not due to changes in α2 autoreceptor or norepinephrine transporter (NET) function. Prazosin (α1-AR antagonist) and suramin (P2 receptor antagonist) inhibited neurogenic MA constriction equally in all groups. Arterial reactivity to exogenous norepinephrine (NE; 10-8 - 10-5 M) was lower in HFD versus CD at 10-wk in males. Female MA reactivity to exogenous ATP was lower at 24-weeks compared to earlier time points. HFD did not affect tyrosine hydroxylase (TH) or the vesicular nucleotide transporter (VNUT) nerve density in MA from both sexes. NE content was lower in MA but higher in plasma at 24-wk compared to 10- and 17-wk in both sexes. In conclusion, HFD-induced hypertension is not driven by increased sympathetic neurotransmission to MA in male and female Dahl ss rats.
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Affiliation(s)
- Kibrom M Alula
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824, USA
| | - Rebecca Biltz
- The Neuroscience Program, Michigan State University, East Lansing, MI 48824, USA
| | - Hui Xu
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824, USA; The Neuroscience Program, Michigan State University, East Lansing, MI 48824, USA
| | - Hannah Garver
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824, USA
| | - Erinn L Laimon-Thomson
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824, USA
| | - Gregory D Fink
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824, USA; The Neuroscience Program, Michigan State University, East Lansing, MI 48824, USA
| | - James J Galligan
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824, USA; The Neuroscience Program, Michigan State University, East Lansing, MI 48824, USA.
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Xie L, Di X, Zhao F, Yao J, Liu Z, Li C, Liu B, Wang X, Zhang J. Increased Respiratory Modulation of Blood Pressure in Hypertensive Patients. Front Physiol 2019; 10:1111. [PMID: 31507459 PMCID: PMC6718561 DOI: 10.3389/fphys.2019.01111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 08/12/2019] [Indexed: 11/20/2022] Open
Abstract
Objective Although the important role of respiratory modulation of the cardiovascular system in the development of hypertension has been demonstrated in animal studies, little research has assessed this modulation in essential hypertensive patients. We aimed to explore whether respiratory-related variations in cardiovascular variables are changed in hypertensive patients and their potential relationships with the respiratory pattern. Methods Respiration, ECG, and beat-to-beat blood pressure (BP) were simultaneously measured in 46 participants (24 hypertensive patients and 22 normotensive participants) during rest and a mental arithmetic task (MAT). Respiratory-triggered averaging and orthogonal subspace projection methods were used to assess the respiratory modulations of BP and heart rate (HR). Respiratory parameters including inspiratory time, expiratory time, respiratory rate and their variabilities were also characterized. Results The inspiratory time, expiratory time, respiratory rate and their variabilities were not different between hypertensive and normotensives. Additionally, the modulation of HR by respiration was also similar between the two groups. Hypertensive patients exhibited an amplified respiratory modulation of systolic BP (SBP), as assessed from the amplitude of respiratory-related changes and the percentage of the power of respiratory-related variation, and also reflected from the temporal pattern of respiratory modulation of SBP. The exaggerated respiratory-related variation of SBP in hypertensive patients accounted for ≈23% of the total power of SBP, producing an absolute change of ≈4.5 mmHg in SBP. MAT was characterized by decreased inspiratory time and increased variabilities of expiratory time and respiratory rate with no changes in the amplitude of respiratory modulations. Conclusion Hypertensive patients had excessive respiratory modulation of SBP, despite having similar respiratory pattern with normotensives. These findings highlight the importance of respiratory influence in BP variation and suggest that respiratory modulation of SBP may have prognostic information for cardiovascular events in hypertensive patients.
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Affiliation(s)
- Lin Xie
- Key Laboratory of Biomedical Information Engineering of Education Ministry, Xi'an Jiaotong University, Xi'an, China
| | - Xiaohui Di
- Key Laboratory of Biomedical Information Engineering of Education Ministry, Xi'an Jiaotong University, Xi'an, China
| | - Fadong Zhao
- Key Laboratory of Biomedical Information Engineering of Education Ministry, Xi'an Jiaotong University, Xi'an, China
| | - Jie Yao
- Key Laboratory of Biomedical Information Engineering of Education Ministry, Xi'an Jiaotong University, Xi'an, China
| | - Zhiheng Liu
- Department of Cardiology, No. 451 Hospital of Chinese People's Liberation Army, Xi'an, China
| | - Chaomin Li
- Department of Cardiology, No. 451 Hospital of Chinese People's Liberation Army, Xi'an, China
| | - Binbin Liu
- Key Laboratory of Biomedical Information Engineering of Education Ministry, Xi'an Jiaotong University, Xi'an, China
| | - Xiaoni Wang
- Key Laboratory of Biomedical Information Engineering of Education Ministry, Xi'an Jiaotong University, Xi'an, China
| | - Jianbao Zhang
- Key Laboratory of Biomedical Information Engineering of Education Ministry, Xi'an Jiaotong University, Xi'an, China
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