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Aguilar BA, Vieira S, Veiga AC, da Silva JVMB, Paixao TV, Rodrigues KP, Tank J, Ruys LA, de Souza HCD. Physical exercise is essential for increasing ventricular contractility in hypertensive rats treated with losartan. Hypertens Res 2024; 47:1350-1361. [PMID: 38418900 DOI: 10.1038/s41440-024-01611-z] [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: 08/09/2023] [Revised: 01/07/2024] [Accepted: 01/27/2024] [Indexed: 03/02/2024]
Abstract
The treatment of hypertensive patients with losartan is very common. Despite the reduction in blood pressure, its effects on cardiac contractility and sympathetic autonomic drive are still controversial. In turn, aerobic physical training (APT) also presents an important therapeutic option, providing significant improvements in cardiovascular autonomic control, however little is known about its effects on cardiac contractility, especially when associated with losartan. Therefore, we investigated in spontaneously hypertensive rats (SHR) the effects of losartan and APT on cardiac hemodynamics and functionality, with emphasis on autonomic tonic balance and cardiac contractility. Sixty-four SHR (18 weeks old) were divided into four groups (N = 16): vehicle; vehicle submitted to APT through swimming for 12 weeks; treated with losartan (5 mg·kg-1·d-1) for 12 weeks; and treated with losartan associated with APT. The groups were submitted to cardiac morphological and functional analysis by echocardiography; double blockade of cardiac autonomic receptors with atropine and propranolol; and coronary bed reactivity and left ventricular contractility analyses by the Langendorff technique. APT improved functional parameters and autonomic balance by reducing sympathetic drive and/or increasing vagal drive. In contrast, it promoted a concentric remodeling of the left ventricle (LV). Treatment with losartan reduced sympathetic autonomic drive and cardiac morphological parameters, but there were no significant gains in cardiac functionality and contractility. When combined, the concentric remodeling of the LV to APT was abolished and gains in cardiac functionality and contractility were observed. Our findings suggest that the effects of losartan and APT are complementary and should be applied together in the treatment of hypertension. In spontaneously hypertensive rats, the combination of aerobic physical training with losartan treatment was crucial to greater blood pressure reductions and an increase in left ventricular contractility. Furthermore, losartan treatment prevented the concentric left ventricular remodeling caused by aerobic physical training.
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Affiliation(s)
- Bruno Augusto Aguilar
- Department of Health Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Suenimeire Vieira
- Department of Health Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Ana Catarine Veiga
- Department of Health Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | | | - Tallys Velasco Paixao
- Department of Health Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Karine Pereira Rodrigues
- Department of Health Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Jens Tank
- Department of Cardiovascular Aerospace Medicine, Institute of Aerospace Medicine, German Aerospace Center, 51147, Cologne, Germany
| | - Leticia Araujo Ruys
- Department of Health Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Hugo Celso Dutra de Souza
- Department of Health Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
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Wilson AJ, Sands GB, Wang VY, Pontre B, Ennis DB, Young AA, LeGrice IJ, Nash MP. Quinapril treatment curtails decline of global longitudinal strain and mechanical function in hypertensive rats. J Hypertens 2023; 41:1606-1614. [PMID: 37466436 DOI: 10.1097/hjh.0000000000003512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
BACKGROUND Left ventricular (LV) global longitudinal strain (GLS) has been proposed as an early imaging biomarker of cardiac mechanical dysfunction. OBJECTIVE To assess the impact of angiotensin-converting enzyme (ACE) inhibitor treatment of hypertensive heart disease on LV GLS and mechanical function. METHODS The spontaneously hypertensive rat (SHR) model of hypertensive heart disease ( n = 38) was studied. A subset of SHRs received quinapril (TSHR, n = 16) from 3 months (mo). Wistar Kyoto rats (WKY, n = 13) were used as controls. Tagged cardiac MRI was performed using a 4.7 T Varian preclinical scanner. RESULTS The SHRs had significantly lower LV ejection fraction (EF) than the WKYs at 3 mo (53.0 ± 1.7% vs. 69.6 ± 2.1%, P < 0.05), 14 mo (57.0 ± 2.5% vs. 74.4 ± 2.9%, P < 0.05) and 24 mo (50.1 ± 2.4% vs. 67.0 ± 2.0%, P < 0.01). At 24 mo, ACE inhibitor treatment was associated with significantly greater LV EF in TSHRs compared to untreated SHRs (64.2 ± 3.4% vs. 50.1 ± 2.4%, P < 0.01). Peak GLS magnitude was significantly lower in SHRs compared with WKYs at 14 months (7.5% ± 0.4% vs. 9.9 ± 0.8%, P < 0.05). At 24 months, Peak GLS magnitude was significantly lower in SHRs compared with both WKYs (6.5 ± 0.4% vs. 9.7 ± 1.0%, P < 0.01) and TSHRs (6.5 ± 0.4% vs. 9.6 ± 0.6%, P < 0.05). CONCLUSIONS ACE inhibitor treatment curtails the decline in global longitudinal strain in hypertensive rats, with the treatment group exhibiting significantly greater LV EF and GLS magnitude at 24 mo compared with untreated SHRs.
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Affiliation(s)
| | | | - Vicky Y Wang
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Beau Pontre
- Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand
| | - Daniel B Ennis
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Alistair A Young
- Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand
- Department of Biomedical Engineering, King's College London, London, UK
| | | | - Martyn P Nash
- Auckland Bioengineering Institute
- Department of Engineering Science, University of Auckland, Auckland, New Zealand
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Chen K, Guan Y, Wu S, Quan D, Yang D, Wu H, LV L, Zhang G. Salvianolic acid D: A potent molecule that protects against heart failure induced by hypertension via Ras signalling pathway and PI3K/Akt signalling pathway. Heliyon 2022; 9:e12337. [PMID: 36825182 PMCID: PMC9941879 DOI: 10.1016/j.heliyon.2022.e12337] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 07/17/2022] [Accepted: 12/06/2022] [Indexed: 12/14/2022] Open
Abstract
Ethnopharmacological relevance Salvianolic acid D (Sal D) is a natural substance extracted from Radix Salviae that performs a cardiovascular benefit. However, the protective mechanism of Sal-D for heart failure remains uncertain. Aim of the study In this study, we aim to evaluate the effect of Sal D on heart failure and elucidate its underlying mechanisms. Materials and methods Using the spontaneously hypertensive rats (SHR) as a cardiac remodelling model, the cardioprotective effect of Sal D was evaluated. Employing bioinformatics analysis, the related mechanisms of Sal D treatment on heart failure were identified and validated by Western blot and polymerase chain reaction. Results The results showed that Sal D significantly improved cardiac function and attenuated cardiac hypertrophy. Besides, Sal D impaired mitochondrial structure and restored the energy charge of cardiomyocytes managed by angiotensin II. Bioinformatics analysis suggested that Sal D might improve heart failure by modulating the Ras and PI3K/AKT signalling pathways verified in vitro and in vivo. Conclusion In summary, Sal D can improve the heart function of SHR by inhibiting the Ras signalling pathway and activating the PI3K/AKT signalling pathway.
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Affiliation(s)
- Kai Chen
- School of Traditional Chinese Medicine, Southern Medical University, China,Shenzhen Hospital, Southern Medical University, China
| | - Yiqing Guan
- School of Traditional Chinese Medicine, Southern Medical University, China
| | - Shaoyu Wu
- School of Pharmaceutical Sciences, Southern Medical University, China
| | - Dongling Quan
- School of Pharmaceutical Sciences, Southern Medical University, China
| | - Danni Yang
- School of Pharmaceutical Sciences, Southern Medical University, China
| | - Huanxian Wu
- School of Pharmaceutical Sciences, Southern Medical University, China
| | - Lin LV
- School of Pharmaceutical Sciences, Southern Medical University, China,Corresponding author.
| | - Guohua Zhang
- School of Traditional Chinese Medicine, Southern Medical University, China,Corresponding author.
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Oberhoffer FS, Li P, Jakob A, Dalla-Pozza R, Haas NA, Mandilaras G. Energy Drinks Decrease Left Ventricular Efficiency in Healthy Children and Teenagers: A Randomized Trial. SENSORS (BASEL, SWITZERLAND) 2022; 22:7209. [PMID: 36236307 PMCID: PMC9572576 DOI: 10.3390/s22197209] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 09/17/2022] [Accepted: 09/19/2022] [Indexed: 06/16/2023]
Abstract
Background: Minors are considered the main consumer group of energy drinks (EDs). The aim of this study was to investigate the acute effects of ED consumption on left ventricular (LV) hemodynamics and efficiency in healthy children and teenagers. Methods: This study was a randomized, single-blind, placebo-controlled, crossover clinical trial. Study participants consumed a weight-adjusted amount of an ED or a placebo on two consecutive days. LV hemodynamics and efficiency parameters were evaluated non-invasively by generating LV pressure−volume loops (PVLs) through simultaneous echocardiography and blood pressure measurement. Results: A total of 24 children and teenagers (14.90 ± 2.27 years, 13 male) were included in the present study. Conventional echocardiographic parameters of LV function did not show significant differences between both beverage groups. The non-invasive generation of LV PVLs revealed a significantly lower cardiac efficiency 240 min after the ED consumption compared to the placebo intake (140.72 (133.21−149.73) mmHg vs. 135.60 (124.78−140.33) mmHg, p < 0.01). Conclusions: Acute ED consumption is associated with a significantly lower cardiac efficiency in healthy minors. The generation of non-invasive LV PVLs might be beneficial in the assessment of subtle changes in LV efficiency. Further studies need to investigate the influence of chronic ED consumption on LV function and morphology.
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Fan Y, Coll-Font J, van den Boomen M, Kim JH, Chen S, Eder RA, Roche ET, Nguyen CT. Characterization of Exercise-Induced Myocardium Growth Using Finite Element Modeling and Bayesian Optimization. Front Physiol 2021; 12:694940. [PMID: 34434115 PMCID: PMC8381603 DOI: 10.3389/fphys.2021.694940] [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: 04/14/2021] [Accepted: 07/19/2021] [Indexed: 02/03/2023] Open
Abstract
Cardiomyocyte growth can occur in both physiological (exercised-induced) and pathological (e.g., volume overload and pressure overload) conditions leading to left ventricular (LV) hypertrophy. Studies using animal models and histology have demonstrated the growth and remodeling process at the organ level and tissue-cellular level, respectively. However, the driving factors of growth and the mechanistic link between organ, tissue, and cellular growth remains poorly understood. Computational models have the potential to bridge this gap by using constitutive models that describe the growth and remodeling process of the myocardium coupled with finite element (FE) analysis to model the biomechanics of the heart at the organ level. Using subject-specific imaging data of the LV geometry at two different time points, an FE model can be created with the inverse method to characterize the growth parameters of each subject. In this study, we developed a framework that takes in vivo cardiac magnetic resonance (CMR) imaging data of exercised porcine model and uses FE and Bayesian optimization to characterize myocardium growth in the transverse and longitudinal directions. The efficacy of this framework was demonstrated by successfully predicting growth parameters of 18 synthetic LV targeted masks which were generated from three LV porcine geometries. The framework was further used to characterize growth parameters in 4 swine subjects that had been exercised. The study suggested that exercise-induced growth in swine is prone to longitudinal cardiomyocyte growth (58.0 ± 19.6% after 6 weeks and 79.3 ± 15.6% after 12 weeks) compared to transverse growth (4.0 ± 8.0% after 6 weeks and 7.8 ± 9.4% after 12 weeks). This framework can be used to characterize myocardial growth in different phenotypes of LV hypertrophy and can be incorporated with other growth constitutive models to study different hypothetical growth mechanisms.
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Affiliation(s)
- Yiling Fan
- Cardiovascular Bioengineering and Imaging Laboratory, Cardiology Division, Massachusetts General Hospital, Charlestown, MA, United States,Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States,Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Jaume Coll-Font
- Cardiovascular Bioengineering and Imaging Laboratory, Cardiology Division, Massachusetts General Hospital, Charlestown, MA, United States,Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States,Harvard Medical School, Boston, MA, United States
| | - Maaike van den Boomen
- Cardiovascular Bioengineering and Imaging Laboratory, Cardiology Division, Massachusetts General Hospital, Charlestown, MA, United States,Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States,Harvard Medical School, Boston, MA, United States
| | - Joan H. Kim
- Cardiovascular Bioengineering and Imaging Laboratory, Cardiology Division, Massachusetts General Hospital, Charlestown, MA, United States
| | - Shi Chen
- Cardiovascular Bioengineering and Imaging Laboratory, Cardiology Division, Massachusetts General Hospital, Charlestown, MA, United States
| | - Robert Alan Eder
- Cardiovascular Bioengineering and Imaging Laboratory, Cardiology Division, Massachusetts General Hospital, Charlestown, MA, United States
| | - Ellen T. Roche
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States,Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, United States,Harvard Medical School, Boston, MA, United States,*Correspondence: Ellen T. Roche,
| | - Christopher T. Nguyen
- Cardiovascular Bioengineering and Imaging Laboratory, Cardiology Division, Massachusetts General Hospital, Charlestown, MA, United States,Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States,Harvard Medical School, Boston, MA, United States,Christopher T. Nguyen,
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Niestrawska JA, Augustin CM, Plank G. Computational modeling of cardiac growth and remodeling in pressure overloaded hearts-Linking microstructure to organ phenotype. Acta Biomater 2020; 106:34-53. [PMID: 32058078 PMCID: PMC7311197 DOI: 10.1016/j.actbio.2020.02.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 02/06/2020] [Accepted: 02/07/2020] [Indexed: 12/25/2022]
Abstract
Cardiac growth and remodeling (G&R) refers to structural changes in myocardial tissue in response to chronic alterations in loading conditions. One such condition is pressure overload where elevated wall stresses stimulate the growth in cardiomyocyte thickness, associated with a phenotype of concentric hypertrophy at the organ scale, and promote fibrosis. The initial hypertrophic response can be considered adaptive and beneficial by favoring myocyte survival, but over time if pressure overload conditions persist, maladaptive mechanisms favoring cell death and fibrosis start to dominate, ultimately mediating the transition towards an overt heart failure phenotype. The underlying mechanisms linking biological factors at the myocyte level to biomechanical factors at the systemic and organ level remain poorly understood. Computational models of G&R show high promise as a unique framework for providing a quantitative link between myocardial stresses and strains at the organ scale to biological regulatory processes at the cellular level which govern the hypertrophic response. However, microstructurally motivated, rigorously validated computational models of G&R are still in their infancy. This article provides an overview of the current state-of-the-art of computational models to study cardiac G&R. The microstructure and mechanosensing/mechanotransduction within cells of the myocardium is discussed and quantitative data from previous experimental and clinical studies is summarized. We conclude with a discussion of major challenges and possible directions of future research that can advance the current state of cardiac G&R computational modeling. STATEMENT OF SIGNIFICANCE: The mechanistic links between organ-scale biomechanics and biological factors at the cellular size scale remain poorly understood as these are largely elusive to investigations using experimental methodology alone. Computational G&R models show high promise to establish quantitative links which allow more mechanistic insight into adaptation mechanisms and may be used as a tool for stratifying the state and predict the progression of disease in the clinic. This review provides a comprehensive overview of research in this domain including a summary of experimental data. Thus, this study may serve as a basis for the further development of more advanced G&R models which are suitable for making clinical predictions on disease progression or for testing hypotheses on pathogenic mechanisms using in-silico models.
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Affiliation(s)
- Justyna A Niestrawska
- Gottfried Schatz Research Center: Division of Biophysics, Medical University of Graz, Graz 8010, Austria
| | - Christoph M Augustin
- Gottfried Schatz Research Center: Division of Biophysics, Medical University of Graz, Graz 8010, Austria.
| | - Gernot Plank
- Gottfried Schatz Research Center: Division of Biophysics, Medical University of Graz, Graz 8010, Austria; BioTechMed-Graz, Austria
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7
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Li J, Kemp BA, Howell NL, Massey J, Mińczuk K, Huang Q, Chordia MD, Roy RJ, Patrie JT, Davogustto GE, Kramer CM, Epstein FH, Carey RM, Taegtmeyer H, Keller SR, Kundu BK. Metabolic Changes in Spontaneously Hypertensive Rat Hearts Precede Cardiac Dysfunction and Left Ventricular Hypertrophy. J Am Heart Assoc 2020; 8:e010926. [PMID: 30764689 PMCID: PMC6405673 DOI: 10.1161/jaha.118.010926] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Background Sustained pressure overload leads to changes in cardiac metabolism, function, and structure. Both time course and causal relationships between these changes are not fully understood. Therefore, we studied spontaneously hypertensive rats (SHR) during early hypertension development and compared them to control Wistar Kyoto rats. Methods and Results We serially evaluated myocardial glucose uptake rates (Ki) with dynamic 2‐[18F] fluoro‐2‐deoxy‐D‐glucose positron emission tomography, and ejection fraction and left ventricular mass to body weight ratios with cardiac magnetic resonance imaging in vivo, determined glucose uptake and oxidation rates in isolated perfused hearts, and analyzed metabolites, mammalian target of rapamycin activity and endoplasmic reticulum stress in dissected hearts. When compared with Wistar Kyoto rats, SHR demonstrated increased glucose uptake rates (Ki) in vivo, and reduced ejection fraction as early as 2 months of age when hypertension was established. Isolated perfused SHR hearts showed increased glucose uptake and oxidation rates starting at 1 month. Cardiac metabolite analysis at 2 months of age revealed elevated pyruvate, fatty acyl‐ and branched chain amino acid‐derived carnitines, oxidative stress, and inflammation. Mammalian target of rapamycin activity increased in SHR beginning at 2 months. Left ventricular mass to body weight ratios and endoplasmic reticulum stress were elevated in 5 month‐old SHR. Conclusions Thus, in a genetic hypertension model, chronic cardiac pressure overload promptly leads to increased myocardial glucose uptake and oxidation, and to metabolite abnormalities. These coincide with, or precede, cardiac dysfunction while left ventricular hypertrophy develops only later. Myocardial metabolic changes may thus serve as early diagnostic markers for hypertension‐induced left ventricular hypertrophy.
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Affiliation(s)
- Jie Li
- 1 Department of Radiology and Medical Imaging University of Virginia Charlottesville VA
| | - Brandon A Kemp
- 2 Division of Endocrinology and Metabolism Department of Medicine University of Virginia Charlottesville VA
| | - Nancy L Howell
- 2 Division of Endocrinology and Metabolism Department of Medicine University of Virginia Charlottesville VA
| | - James Massey
- 1 Department of Radiology and Medical Imaging University of Virginia Charlottesville VA.,3 Department of Biomedical Engineering University of Virginia Charlottesville VA
| | - Krzysztof Mińczuk
- 1 Department of Radiology and Medical Imaging University of Virginia Charlottesville VA
| | - Qiao Huang
- 1 Department of Radiology and Medical Imaging University of Virginia Charlottesville VA
| | - Mahendra D Chordia
- 1 Department of Radiology and Medical Imaging University of Virginia Charlottesville VA
| | - R Jack Roy
- 1 Department of Radiology and Medical Imaging University of Virginia Charlottesville VA
| | - James T Patrie
- 4 Department of Public Health Sciences University of Virginia Charlottesville VA
| | - Giovanni E Davogustto
- 5 McGovern Medical School University of Texas Health Science Center in Houston Houston TX
| | - Christopher M Kramer
- 6 Department of Cardiovascular Medicine University of Virginia Charlottesville VA
| | - Frederick H Epstein
- 3 Department of Biomedical Engineering University of Virginia Charlottesville VA
| | - Robert M Carey
- 2 Division of Endocrinology and Metabolism Department of Medicine University of Virginia Charlottesville VA
| | - Heinrich Taegtmeyer
- 5 McGovern Medical School University of Texas Health Science Center in Houston Houston TX
| | - Susanna R Keller
- 2 Division of Endocrinology and Metabolism Department of Medicine University of Virginia Charlottesville VA
| | - Bijoy K Kundu
- 1 Department of Radiology and Medical Imaging University of Virginia Charlottesville VA.,3 Department of Biomedical Engineering University of Virginia Charlottesville VA.,7 Cardiovascular Research Center University of Virginia Charlottesville VA
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Left ventricular remodelling among Turner syndrome patients: insights from non-invasive 3D echocardiography-derived pressure-volume loop analysis. Clin Res Cardiol 2019; 109:892-903. [PMID: 31786629 DOI: 10.1007/s00392-019-01579-8] [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] [Received: 04/01/2019] [Accepted: 11/20/2019] [Indexed: 01/15/2023]
Abstract
BACKGROUND Turner syndrome (TS) is a X-chromosomal disease affecting one in 2500-3000 female newborns. TS individuals are at high cardiovascular risk and more likely to be overweight or obese. The aim of this study was to assess left ventricular performance in TS patients through three-dimensional speckle tracking echocardiography (3DSTE) and non-invasive left ventricular pressure-volume loop (PVL) analysis. Moreover, this study focused on the impact of excess weight on the left ventricular efficiency in TS patients. METHODS Thirty-six TS patients and 19 healthy age-matched controls were included in this study. 3DSTE and non-invasive left ventricular PVL analysis were performed and left ventricular efficiency parameters were calculated. RESULTS TS patients had significantly lower values than controls in longitudinal strain (- 16.67 ± 3.23% vs. - 18.47 ± 1.87%; p = 0.029), but significantly higher values for arterial elastance (BSA) (3.31, 1.87-5.88 mmHg/mL vs. 2.99, 2.31-4.61 mmHg/mL; p = 0.011) and cardiac work (BSA) (292,070 ± 71,348 mmHg*mL*HR vs. 248,595 ± 70,510 mmHg*mL*HR; p = 0.036). Compared with normal weight patients, overweight and obese TS subjects demonstrated worse left ventricular efficiency (175.08 ± 17.73 mmHg vs. 157.24 ± 26.75 mmHg; p = 0.037). Even after excluding TS patients with cardiovascular morbidity, arterial elastance (BSA) was compared to healthy peers, significantly increased in TS patients. CONCLUSIONS 3DSTE and non-invasive left ventricular PVL analysis might be useful tools to detect early cardiac changes in TS. Arterial elastance seems to be significantly increased in TS patients, independent of cardiovascular morbidity. Compared with normal weight TS patients, overweight/obese TS patients displayed lower left ventricular efficiency.
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9
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Hasaballa AI, Wang VY, Sands GB, Wilson AJ, Young AA, LeGrice IJ, Nash MP. Microstructurally Motivated Constitutive Modeling of Heart Failure Mechanics. Biophys J 2019; 117:2273-2286. [PMID: 31653449 DOI: 10.1016/j.bpj.2019.09.038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 09/18/2019] [Accepted: 09/24/2019] [Indexed: 10/25/2022] Open
Abstract
Heart failure (HF) is one of the leading causes of death worldwide. HF is associated with substantial microstructural remodeling, which is linked to changes in left ventricular geometry and impaired cardiac function. The role of myocardial remodeling in altering the mechanics of failing hearts remains unclear. Structurally based constitutive modeling provides an approach to improve understanding of the relationship between biomechanical function and tissue organization in cardiac muscle during HF. In this study, we used cardiac magnetic resonance imaging and extended-volume confocal microscopy to quantify the remodeling of left ventricular geometry and myocardial microstructure of healthy and spontaneously hypertensive rat hearts at the ages of 12 and 24 months. Passive cardiac mechanical function was characterized using left ventricular pressure-volume compliance measurements. We have developed a, to our knowledge, new structurally based biomechanical constitutive equation built on parameters quantified directly from collagen distributions observed in confocal images of the myocardium. Three-dimensional left ventricular finite element models were constructed from subject-specific in vivo magnetic resonance imaging data. The structurally based constitutive equation was integrated into geometrically subject-specific finite element models of the hearts and used to investigate the underlying mechanisms of ventricular dysfunction during HF. Using a single pair of material parameters for all hearts, we were able to produce compliance curves that reproduced all of the experimental compliance measurements. The value of this study is not limited to reproducing the mechanical behavior of healthy and diseased hearts, but it also provides important insights into the structure-function relationship of diseased myocardium that will help pave the way toward more effective treatments for HF.
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Affiliation(s)
- Abdallah I Hasaballa
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Vicky Y Wang
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Gregory B Sands
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand; Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Alexander J Wilson
- Radiological Sciences Laboratory, School of Medicine, Stanford University, Stanford, California
| | - Alistair A Young
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand; Department of Biomedical Engineering, King's College London, London, United Kingdom
| | - Ian J LeGrice
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand; Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Martyn P Nash
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand; Department of Engineering Science, University of Auckland, Auckland, New Zealand.
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10
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Bardsley EN, Davis H, Ajijola OA, Buckler KJ, Ardell JL, Shivkumar K, Paterson DJ. RNA Sequencing Reveals Novel Transcripts from Sympathetic Stellate Ganglia During Cardiac Sympathetic Hyperactivity. Sci Rep 2018; 8:8633. [PMID: 29872217 PMCID: PMC5988725 DOI: 10.1038/s41598-018-26651-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 05/15/2018] [Indexed: 12/15/2022] Open
Abstract
Cardiovascular disease is the most prevalent age-related illness worldwide, causing approximately 15 million deaths every year. Hypertension is central in determining cardiovascular risk and is a strong predictive indicator of morbidity and mortality; however, there remains an unmet clinical need for disease-modifying and prophylactic interventions. Enhanced sympathetic activity is a well-established contributor to the pathophysiology of hypertension, however the cellular and molecular changes that increase sympathetic neurotransmission are not known. The aim of this study was to identify key changes in the transcriptome in normotensive and spontaneously hypertensive rats. We validated 15 of our top-scoring genes using qRT-PCR, and network and enrichment analyses suggest that glutamatergic signalling plays a key role in modulating Ca2+ balance within these ganglia. Additionally, phosphodiesterase activity was found to be altered in stellates obtained from the hypertensive rat, suggesting that impaired cyclic nucleotide signalling may contribute to disturbed Ca2+ homeostasis and sympathetic hyperactivity in hypertension. We have also confirmed the presence of these transcripts in human donor stellate samples, suggesting that key genes coupled to neurotransmission are conserved. The data described here may provide novel targets for future interventions aimed at treating sympathetic hyperactivity associated with cardiovascular disease and other dysautonomias.
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Affiliation(s)
- Emma N Bardsley
- Wellcome Trust OXION Initiative in Ion Channels and Disease, Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, Sherrington Building, University of Oxford, Oxford, OX1 3PT, UK.
| | - Harvey Davis
- Wellcome Trust OXION Initiative in Ion Channels and Disease, Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, Sherrington Building, University of Oxford, Oxford, OX1 3PT, UK
| | - Olujimi A Ajijola
- UCLA Cardiac Arrhythmia Center, 100 Medical Plaza, Suite 660, Los Angeles, CA, 90095, USA
| | - Keith J Buckler
- Wellcome Trust OXION Initiative in Ion Channels and Disease, Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, Sherrington Building, University of Oxford, Oxford, OX1 3PT, UK
| | - Jeffrey L Ardell
- UCLA Cardiac Arrhythmia Center, 100 Medical Plaza, Suite 660, Los Angeles, CA, 90095, USA
| | - Kalyanam Shivkumar
- UCLA Cardiac Arrhythmia Center, 100 Medical Plaza, Suite 660, Los Angeles, CA, 90095, USA
| | - David J Paterson
- Wellcome Trust OXION Initiative in Ion Channels and Disease, Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, Sherrington Building, University of Oxford, Oxford, OX1 3PT, UK.
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Bardsley EN, Davis H, Buckler KJ, Paterson DJ. Neurotransmitter Switching Coupled to β-Adrenergic Signaling in Sympathetic Neurons in Prehypertensive States. Hypertension 2018; 71:1226-1238. [PMID: 29686017 PMCID: PMC5959210 DOI: 10.1161/hypertensionaha.118.10844] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Revised: 01/18/2018] [Accepted: 03/26/2018] [Indexed: 01/16/2023]
Abstract
Single or combinatorial administration of β-blockers is a mainstay treatment strategy for conditions caused by sympathetic overactivity. Conventional wisdom suggests that the main beneficial effect of β-blockers includes resensitization and restoration of β1-adrenergic signaling pathways in the myocardium, improvements in cardiomyocyte contractility, and reversal of ventricular sensitization. However, emerging evidence indicates that another beneficial effect of β-blockers in disease may reside in sympathetic neurons. We investigated whether β-adrenoceptors are present on postganglionic sympathetic neurons and facilitate neurotransmission in a feed-forward manner. Using a combination of immunocytochemistry, RNA sequencing, Förster resonance energy transfer, and intracellular Ca2+ imaging, we demonstrate the presence of β-adrenoceptors on presynaptic sympathetic neurons in both human and rat stellate ganglia. In diseased neurons from the prehypertensive rat, there was enhanced β-adrenoceptor-mediated signaling predominantly via β2-adrenoceptor activation. Moreover, in human and rat neurons, we identified the presence of the epinephrine-synthesizing enzyme PNMT (phenylethanolamine-N-methyltransferase). Using high-pressure liquid chromatography with electrochemical detection, we measured greater epinephrine content and evoked release from the prehypertensive rat cardiac-stellate ganglia. We conclude that neurotransmitter switching resulting in enhanced epinephrine release, may provide presynaptic positive feedback on β-adrenoceptors to promote further release, that leads to greater postsynaptic excitability in disease, before increases in arterial blood pressure. Targeting neuronal β-adrenoceptor downstream signaling could provide therapeutic opportunity to minimize end-organ damage caused by sympathetic overactivity.
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Affiliation(s)
- Emma N Bardsley
- From the Wellcome Trust OXION Initiative in Ion Channels and Disease, Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, United Kingdom.
| | - Harvey Davis
- From the Wellcome Trust OXION Initiative in Ion Channels and Disease, Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, United Kingdom
| | - Keith J Buckler
- From the Wellcome Trust OXION Initiative in Ion Channels and Disease, Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, United Kingdom
| | - David J Paterson
- From the Wellcome Trust OXION Initiative in Ion Channels and Disease, Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, United Kingdom.
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Wilson AJ, Wang VY, Sands GB, Young AA, Nash MP, LeGrice IJ. Increased cardiac work provides a link between systemic hypertension and heart failure. Physiol Rep 2017; 5:5/1/e13104. [PMID: 28082430 PMCID: PMC5256162 DOI: 10.14814/phy2.13104] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 12/06/2016] [Accepted: 11/29/2016] [Indexed: 11/24/2022] Open
Abstract
The spontaneously hypertensive rat (SHR) is an established model of human hypertensive heart disease transitioning into heart failure. The study of the progression to heart failure in these animals has been limited by the lack of longitudinal data. We used MRI to quantify left ventricular mass, volume, and cardiac work in SHRs at age 3 to 21 month and compared these indices to data from Wistar-Kyoto (WKY) controls. SHR had lower ejection fraction compared with WKY at all ages, but there was no difference in cardiac output at any age. At 21 month the SHR had significantly elevated stroke work (51 ± 3 mL.mmHg SHR vs. 24 ± 2 mL.mmHg WKY; n = 8, 4; P < 0.001) and cardiac minute work (14.2 ± 1.2 L.mmHg/min SHR vs. 6.2 ± 0.8 L.mmHg/min WKY; n = 8, 4; P < 0.001) compared to control, in addition to significantly larger left ventricular mass to body mass ratio (3.61 ± 0.15 mg/g SHR vs. 2.11 ± 0.008 mg/g WKY; n = 8, 6; P < 0.001). SHRs showed impaired systolic function, but developed hypertrophy to compensate and successfully maintained cardiac output. However, this was associated with an increase in cardiac work at age 21 month, which has previously demonstrated fibrosis and cell death. The interplay between these factors may be the mechanism for progression to failure in this animal model.
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Affiliation(s)
- Alexander J Wilson
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand .,Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Vicky Y Wang
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Gregory B Sands
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.,Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Alistair A Young
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.,Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand
| | - Martyn P Nash
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.,Department of Engineering Science, University of Auckland, Auckland, New Zealand
| | - Ian J LeGrice
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.,Department of Physiology, University of Auckland, Auckland, New Zealand
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