1
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Xu D, McBride E, Kalra K, Wong K, Guyton RA, Sarin EL, Padala M. Undersizing mitral annuloplasty alters left ventricular mechanics in a swine model of ischemic mitral regurgitation. J Thorac Cardiovasc Surg 2022; 164:850-861.e8. [PMID: 33288234 PMCID: PMC8099928 DOI: 10.1016/j.jtcvs.2020.09.141] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 09/23/2020] [Accepted: 09/28/2020] [Indexed: 10/23/2022]
Abstract
OBJECTIVE Undersizing mitral annuloplasty (UMA) is a frequently used surgical repair technique to correct ischemic mitral regurgitation in patients with heart failure. In this study, we sought to test the hypothesis that downsizing the mitral annulus can adversely affect the shape and mechanics of the left ventricle inhibiting its functional recovery. METHODS Eighteen farm swine that underwent an inferolateral myocardial infarction and developed ischemic mitral regurgitation of >2+ severity after 2 months were assigned as follows: 9 swine received an undersized mitral annuloplasty, 6 received papillary muscle approximation (PMA), and 3 animals did not receive any other intervention. Animals lived another 3 months and cardiac magnetic resonance imaging was performed before termination to assess ventricle mechanics and function. RESULTS Ejection fraction was comparable between the 2 repair groups before surgery, but was significantly lower in UMA at 38.89% ± 7.91% versus 50.83% ± 9.04% in the PMA group (P = .0397). Animals receiving UMA had lower regional peak fractional shortening and reduced systolic and diastolic radial velocities compared with PMA and in some regions were lower than sham. Animals that underwent UMA had higher circumferential strain than sham, but lower than PMA. UMA animals have lower longitudinal strain compared to sham group and lower LV torsion than PMA. CONCLUSIONS Undersizing the mitral annulus with an annuloplasty ring can restore valvular competence, but unphysiologically impair ventricle mechanics. Mitral valve repair strategies should focus not only on restoring valve competence, but preserving ventricle mechanics.
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Affiliation(s)
- Dongyang Xu
- Structural Heart Research & Innovation Laboratory, Carlyle Fraser Heart Center, Emory University Hospital Midtown, Atlanta, Ga
| | - Erin McBride
- Structural Heart Research & Innovation Laboratory, Carlyle Fraser Heart Center, Emory University Hospital Midtown, Atlanta, Ga
| | - Kanika Kalra
- Structural Heart Research & Innovation Laboratory, Carlyle Fraser Heart Center, Emory University Hospital Midtown, Atlanta, Ga
| | - Keawepono Wong
- Structural Heart Research & Innovation Laboratory, Carlyle Fraser Heart Center, Emory University Hospital Midtown, Atlanta, Ga
| | - Robert A Guyton
- Structural Heart Research & Innovation Laboratory, Carlyle Fraser Heart Center, Emory University Hospital Midtown, Atlanta, Ga; Division of Cardiothoracic Surgery, Department of Surgery, Emory University, Atlanta, Ga
| | - Eric L Sarin
- Structural Heart Research & Innovation Laboratory, Carlyle Fraser Heart Center, Emory University Hospital Midtown, Atlanta, Ga; Department of Cardiothoracic Surgery, Inova Heart and Vascular Institute, Fairfax, Va
| | - Muralidhar Padala
- Structural Heart Research & Innovation Laboratory, Carlyle Fraser Heart Center, Emory University Hospital Midtown, Atlanta, Ga; Division of Cardiothoracic Surgery, Department of Surgery, Emory University, Atlanta, Ga.
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2
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Onohara D, Suresh KS, Silverman M, He Q, Kono T, Padala M. Image-Guided Targeted Mitral Valve Tethering with Chordal Encircling Snares as a Preclinical Model of Secondary Mitral Regurgitation. J Cardiovasc Transl Res 2022; 15:653-665. [PMID: 34618333 PMCID: PMC10797638 DOI: 10.1007/s12265-021-10177-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 09/23/2021] [Indexed: 10/20/2022]
Abstract
Development of transcatheter mitral valve interventions has ushered a significant need for large animal models of secondary mitral regurgitation. Though currently used heart failure models that chronically develop secondary mitral regurgitation are viable, the severity is lower than patients, the incubation time is long, and mortality is high. We sought to develop a swine model of acute secondary mitral regurgitation that uses image-guided placement of snares around the mitral chordae. Twenty-seven adult swine (n = 27) were assigned to secondary mitral regurgitation induced by valve tethering with image-guided chordal encircling snares (group 1, n = 7, tether MR (tMR)); secondary mitral regurgitation by percutaneous posterolateral myocardial infarction causing ventricular dysfunction and regurgitation (group 2, n = 6, functional MR (fMR)); and control animals (group 3, n = 14). Regurgitant fraction in tMR was 42.1 ± 14.2%, in fMR was 22 ± 9.6%, and in controls was 5.3 ± 3.8%. Mitral tenting height was 9.6 ± 1.3 mm in tMR, 10.1 ± 1.5 mm in fMR, and 5.8 ± 1.2 mm in controls. Chordal encircling tethers reproducibly induce clinically relevant levels of secondary mitral regurgitation, providing a new animal model for use in translational research.
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Affiliation(s)
- Daisuke Onohara
- Structural Heart Research and Innovation Laboratory, Carlyle Fraser Heart Center, Emory University Hospital Midtown, Atlanta, GA, USA
- Division of Cardiothoracic Surgery, Emory University School of Medicine, Atlanta, GA, USA
| | - Kirthana Sreerangathama Suresh
- Structural Heart Research and Innovation Laboratory, Carlyle Fraser Heart Center, Emory University Hospital Midtown, Atlanta, GA, USA
| | - Michael Silverman
- Structural Heart Research and Innovation Laboratory, Carlyle Fraser Heart Center, Emory University Hospital Midtown, Atlanta, GA, USA
| | - Qi He
- Structural Heart Research and Innovation Laboratory, Carlyle Fraser Heart Center, Emory University Hospital Midtown, Atlanta, GA, USA
| | - Takanori Kono
- Structural Heart Research and Innovation Laboratory, Carlyle Fraser Heart Center, Emory University Hospital Midtown, Atlanta, GA, USA
| | - Muralidhar Padala
- Structural Heart Research and Innovation Laboratory, Carlyle Fraser Heart Center, Emory University Hospital Midtown, Atlanta, GA, USA.
- Division of Cardiothoracic Surgery, Emory University School of Medicine, Atlanta, GA, USA.
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3
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Castillo-Sang M, Nguyen TC. Commentary: The right horse for the race in the repair of secondary mitral regurgitation. J Thorac Cardiovasc Surg 2021; 165:2050-2051. [PMID: 34509294 DOI: 10.1016/j.jtcvs.2021.08.059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 08/25/2021] [Accepted: 08/26/2021] [Indexed: 10/20/2022]
Affiliation(s)
- Mario Castillo-Sang
- Department of Cardiothoracic Surgery, Saint Elizabeth Healthcare, Edgewood, Ky.
| | - Tom C Nguyen
- Division of Cardiothoracic Surgery, Department of Surgery, University of California San Francisco, San Francisco, Calif
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4
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Park MH, Zhu Y, Imbrie-Moore AM, Wang H, Marin-Cuartas M, Paulsen MJ, Woo YJ. Heart Valve Biomechanics: The Frontiers of Modeling Modalities and the Expansive Capabilities of Ex Vivo Heart Simulation. Front Cardiovasc Med 2021; 8:673689. [PMID: 34307492 PMCID: PMC8295480 DOI: 10.3389/fcvm.2021.673689] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 05/17/2021] [Indexed: 01/05/2023] Open
Abstract
The field of heart valve biomechanics is a rapidly expanding, highly clinically relevant area of research. While most valvular pathologies are rooted in biomechanical changes, the technologies for studying these pathologies and identifying treatments have largely been limited. Nonetheless, significant advancements are underway to better understand the biomechanics of heart valves, pathologies, and interventional therapeutics, and these advancements have largely been driven by crucial in silico, ex vivo, and in vivo modeling technologies. These modalities represent cutting-edge abilities for generating novel insights regarding native, disease, and repair physiologies, and each has unique advantages and limitations for advancing study in this field. In particular, novel ex vivo modeling technologies represent an especially promising class of translatable research that leverages the advantages from both in silico and in vivo modeling to provide deep quantitative and qualitative insights on valvular biomechanics. The frontiers of this work are being discovered by innovative research groups that have used creative, interdisciplinary approaches toward recapitulating in vivo physiology, changing the landscape of clinical understanding and practice for cardiovascular surgery and medicine.
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Affiliation(s)
- Matthew H Park
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA, United States.,Department of Mechanical Engineering, Stanford University, Stanford, CA, United States
| | - Yuanjia Zhu
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA, United States.,Department of Bioengineering, Stanford University, Stanford, CA, United States
| | - Annabel M Imbrie-Moore
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA, United States.,Department of Mechanical Engineering, Stanford University, Stanford, CA, United States
| | - Hanjay Wang
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA, United States
| | - Mateo Marin-Cuartas
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA, United States.,University Department of Cardiac Surgery, Leipzig Heart Center, Leipzig, Germany
| | - Michael J Paulsen
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA, United States
| | - Y Joseph Woo
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA, United States.,Department of Bioengineering, Stanford University, Stanford, CA, United States
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5
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Vinciguerra M, Grigioni F, Romiti S, Benfari G, Rose D, Spadaccio C, Cimino S, De Bellis A, Greco E. Ischemic Mitral Regurgitation: A Multifaceted Syndrome with Evolving Therapies. Biomedicines 2021; 9:biomedicines9050447. [PMID: 33919263 PMCID: PMC8143318 DOI: 10.3390/biomedicines9050447] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/14/2021] [Accepted: 04/19/2021] [Indexed: 12/24/2022] Open
Abstract
Dysfunction of the left ventricle (LV) with impaired contractility following chronic ischemia or acute myocardial infarction (AMI) is the main cause of ischemic mitral regurgitation (IMR), leading to moderate and moderate-to-severe mitral regurgitation (MR). The site of AMI exerts a specific influence determining different patterns of adverse LV remodeling. In general, inferior-posterior AMI is more frequently associated with regional structural changes than the anterolateral one, which is associated with global adverse LV remodeling, ultimately leading to different phenotypes of IMR. In this narrative review, starting from the aforementioned categorization, we proceed to describe current knowledge regarding surgical approaches in the management of IMR.
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Affiliation(s)
- Mattia Vinciguerra
- Department of Clinical, Internal Medicine, Anesthesiology and Cardiovascular Sciences, Sapienza University of Rome, 00161 Rome, Italy; (S.R.); (S.C.); (E.G.)
- Correspondence:
| | - Francesco Grigioni
- Unit of Cardiovascular Sciences, Department of Medicine Campus Bio-Medico, University of Rome, 00128 Rome, Italy;
| | - Silvia Romiti
- Department of Clinical, Internal Medicine, Anesthesiology and Cardiovascular Sciences, Sapienza University of Rome, 00161 Rome, Italy; (S.R.); (S.C.); (E.G.)
| | - Giovanni Benfari
- Division of Cardiology, Department of Medicine, University of Verona, 37219 Verona, Italy;
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - David Rose
- Lancashire Cardiac Centre, Blackpool Victoria Hospital, Blackpool FY3 8NP, UK; (D.R.); (C.S.)
| | - Cristiano Spadaccio
- Lancashire Cardiac Centre, Blackpool Victoria Hospital, Blackpool FY3 8NP, UK; (D.R.); (C.S.)
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Sara Cimino
- Department of Clinical, Internal Medicine, Anesthesiology and Cardiovascular Sciences, Sapienza University of Rome, 00161 Rome, Italy; (S.R.); (S.C.); (E.G.)
| | - Antonio De Bellis
- Department of Cardiology and Cardiac Surgery, Casa di Cura “S. Michele”, 81024 Maddaloni, Caserta, Italy;
| | - Ernesto Greco
- Department of Clinical, Internal Medicine, Anesthesiology and Cardiovascular Sciences, Sapienza University of Rome, 00161 Rome, Italy; (S.R.); (S.C.); (E.G.)
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6
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Castillo-Sang M, Nguyen TC, Voeller RK. Commentary: Ischemic mitral regurgitation: From annular restriction to papillary approximation, is it time to reconsider the lost technique? J Thorac Cardiovasc Surg 2020; 164:863-864. [PMID: 33218759 DOI: 10.1016/j.jtcvs.2020.10.056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 10/13/2020] [Accepted: 10/15/2020] [Indexed: 10/23/2022]
Affiliation(s)
- Mario Castillo-Sang
- Department of Cardiothoracic Surgery, Saint Elizabeth Healthcare, Edgewood, Ky.
| | - Tom C Nguyen
- Department of Cardiothoracic and Vascular Surgery, McGovern Medical School, University of Texas Health Science Houston, Houston, Tex
| | - Rochus K Voeller
- Division of Cardiothoracic Surgery, Department of Surgery, University of Minnesota Medical School, Minneapolis, Minn
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7
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Micali LR, Parise G, Moula AI, Alayed Y, Parise O, Matteucci F, de Jong M, Tetta C, Gelsomino S. Are recurrence of ischemic mitral regurgitation and left ventricular reverse remodeling after restrictive annuloplasty ring dependent? Int J Cardiol 2020; 309:55-62. [PMID: 32178901 DOI: 10.1016/j.ijcard.2020.02.068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 12/27/2019] [Accepted: 02/26/2020] [Indexed: 11/18/2022]
Abstract
OBJECTIVE This meta-analysis investigates MR recurrence and degree of left ventricular reverse remodeling (LVRR) in CIMR patients in mitral annuloplasty employing different ring designs. BACKGROUND The deeper understanding of complex changes caused by chronic ischemic mitral regurgitation (CIMR) have led to new generations of rings that, by maintaining normal 3D annular geometry are supposed to enhance long-term repair durability. METHODS A meta-analysis of all available reports in literature of MV repair through different ring design was conducted. Meta-regression was performed to investigate the impact of mitral ring characteristics related to flexibility, planarity, symmetry and single type utilized. Twenty studies encompassing a total of 1876 patients were included at the end of the selection process. RESULTS At meta-regression recurrence of MR was not influenced by the ring employed. Nonetheless, the event rate of MR recurrence in planar rings was 19%. Vs. 11% observed with non-planar rings. Recurrence rate in patients implanted with symmetric rings was 14% whereas it was 7% in asymmetric rings. The non-planar asymmetric IMR-ETlogix showed the lowest recurrence rate (6%). Furthermore, in planar group the reduction of pre- and post-operative LVEDD was - 4%. In the non-planar group, the LVEDD was reduced by 8.6%. In patients implanted with symmetric rings LVEDD reduction was 10.8%. LVRR in the asymmetric group was -5.8%. CONCLUSION MR recurrence occurred the least with asymmetric rings with less disproportionate asymmetry. In contrast, LVRR occurred at a greater extent in symmetric rings.
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Affiliation(s)
- Linda Renata Micali
- Cardiovascular Research Institute Maastricht - CARIM, Maastricht University Medical Centre, the Netherlands
| | - Gianmarco Parise
- Cardiovascular Research Institute Maastricht - CARIM, Maastricht University Medical Centre, the Netherlands
| | - Amalia Ioanna Moula
- Cardiovascular Research Institute Maastricht - CARIM, Maastricht University Medical Centre, the Netherlands
| | - Yazeed Alayed
- Cardiovascular Research Institute Maastricht - CARIM, Maastricht University Medical Centre, the Netherlands
| | - Orlando Parise
- Cardiovascular Research Institute Maastricht - CARIM, Maastricht University Medical Centre, the Netherlands
| | - Francesco Matteucci
- Cardiovascular Research Institute Maastricht - CARIM, Maastricht University Medical Centre, the Netherlands
| | - Monique de Jong
- Cardiovascular Research Institute Maastricht - CARIM, Maastricht University Medical Centre, the Netherlands
| | - Cecilia Tetta
- Cardiovascular Research Institute Maastricht - CARIM, Maastricht University Medical Centre, the Netherlands
| | - Sandro Gelsomino
- Cardiovascular Research Institute Maastricht - CARIM, Maastricht University Medical Centre, the Netherlands.
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8
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Timek TA. Commentary: Escape valve for the pressures of life. J Thorac Cardiovasc Surg 2019; 160:e129-e130. [PMID: 31669026 DOI: 10.1016/j.jtcvs.2019.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 09/03/2019] [Accepted: 09/03/2019] [Indexed: 12/01/2022]
Affiliation(s)
- Tomasz A Timek
- Division of Cardiothoracic Surgery, Spectrum Health, Grand Rapids, Mich; Michigan State University College of Human Medicine, Grand Rapids, Mich.
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9
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Onohara D, Corporan D, Hernandez-Merlo R, Guyton RA, Padala M. Mitral regurgitation worsens cardiac remodeling in ischemic cardiomyopathy in an experimental model. J Thorac Cardiovasc Surg 2019; 160:e107-e125. [PMID: 31562015 DOI: 10.1016/j.jtcvs.2019.06.109] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 06/10/2019] [Accepted: 06/28/2019] [Indexed: 11/17/2022]
Abstract
OBJECTIVE Mitral regurgitation (MR) developing concomitant with ischemic cardiomyopathy is a frequently diagnosed valvular lesion, for which an optimal therapeutic strategy is unknown. The contribution of MR to the ongoing cardiac remodeling from myocardial infarction (MI) remains controversial. We have developed a novel experimental model in which MI and severe MR can be independently introduced, to study the role of MR in chronic remodeling of the ischemic heart. METHODS A total of 98 rats were induced with MI+MR (group 1), MI (group 2), MR (group 3), or sham surgery (group 4). MR was induced by inserting a needle into the anterior mitral leaflet via the ventricular apex in a beating heart. MI was induced by ligating the left coronary artery. Biweekly ultrasound examinations were performed after surgery, and invasive hemodynamic assessments were performed in some rats at 2, 10, and 20 weeks. RESULTS At 2 weeks postsurgery, the mean end-diastolic volume was 432 ± 103 μL in ischemic hearts with MR, compared with 390 ± 76.3 μL in ischemic hearts without MR (a 10.76% difference). By 20 weeks, the mean volume was significantly greater in the former group (767 ± 246 μL vs 580 ± 85 μL; a 32.24% difference). At 2 weeks, mean end-systolic volume was 147 ± 46.8 μL in the ischemic hearts with MR and 147 ± 45.7 μL in those without MR. By 20 weeks, the mean volumes had increased to 357 ± 136.4 μL and 271 ± 82.3 μL, respectively (a 31.73% difference). CONCLUSIONS MR in ischemic hearts significantly increased end-diastolic and end-systolic volumes of the left ventricle, indicating adverse cardiac remodeling and worse systolic function.
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Affiliation(s)
- Daisuke Onohara
- Structural Heart Research and Innovation Laboratory, Carlyle Fraser Heart Center, Emory University Hospital Midtown, Atlanta, Ga
| | - Daniella Corporan
- Structural Heart Research and Innovation Laboratory, Carlyle Fraser Heart Center, Emory University Hospital Midtown, Atlanta, Ga
| | - Roberto Hernandez-Merlo
- Structural Heart Research and Innovation Laboratory, Carlyle Fraser Heart Center, Emory University Hospital Midtown, Atlanta, Ga
| | - Robert A Guyton
- Structural Heart Research and Innovation Laboratory, Carlyle Fraser Heart Center, Emory University Hospital Midtown, Atlanta, Ga; Division of Cardiothoracic Surgery, Joseph P. Whitehead Department of Surgery, Emory University School of Medicine, Atlanta, Ga
| | - Muralidhar Padala
- Structural Heart Research and Innovation Laboratory, Carlyle Fraser Heart Center, Emory University Hospital Midtown, Atlanta, Ga; Division of Cardiothoracic Surgery, Joseph P. Whitehead Department of Surgery, Emory University School of Medicine, Atlanta, Ga.
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10
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Abstract
Numerous animal cardiac exercise models using animal subjects have been established to uncover the cardiovascular physiological mechanism of exercise or to determine the effects of exercise on cardiovascular health and disease. In most cases, animal-based cardiovascular exercise modalities include treadmill running, swimming, and voluntary wheel running with a series of intensities, times, and durations. Those used animals include small rodents (e.g., mice and rats) and large animals (e.g., rabbits, dogs, goats, sheep, pigs, and horses). Depending on the research goal, each experimental protocol should also describe whether its respective exercise treatment can produce the anticipated acute or chronic cardiovascular adaptive response. In this chapter, we will briefly describe the most common kinds of animal models of acute and chronic cardiovascular exercises that are currently being conducted and are likely to be chosen in the near future. Strengths and weakness of animal-based cardiac exercise modalities are also discussed.
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Wang L, Li B, Liu C, Rong T, Yu Y, Gu C. Short- and Medium-Term Effects of Combined Mitral Valve Surgery and Coronary Artery Bypass Grafting Versus Coronary Artery Bypass Grafting Alone for Patients with Moderate Ischemic Mitral Regurgitation: A Meta-Analysis. J Cardiothorac Vasc Anesth 2016; 30:1578-1586. [DOI: 10.1053/j.jvca.2016.06.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Indexed: 11/11/2022]
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12
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Ge L, Wu Y, Soleimani M, Khazalpour M, Takaba K, Tartibi M, Zhang Z, Acevedo-Bolton G, Saloner DA, Wallace AW, Mishra R, Grossi EA, Guccione JM, Ratcliffe MB. Moderate Ischemic Mitral Regurgitation After Posterolateral Myocardial Infarction in Sheep Alters Left Ventricular Shear but Not Normal Strain in the Infarct and Infarct Borderzone. Ann Thorac Surg 2016; 101:1691-9. [PMID: 26857634 DOI: 10.1016/j.athoracsur.2015.10.083] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Revised: 10/05/2015] [Accepted: 10/26/2015] [Indexed: 10/22/2022]
Abstract
BACKGROUND Chronic ischemic mitral regurgitation (CIMR) is associated with poor outcome. Left ventricular (LV) strain after posterolateral myocardial infarction (MI) may drive LV remodeling. Although moderate CIMR has been previously shown to affect LV remodeling, the effect of CIMR on LV strain after posterolateral MI remains unknown. We tested the hypothesis that moderate CIMR alters LV strain after posterolateral MI. METHODS Posterolateral MI was created in 10 sheep. Cardiac magnetic resonance imaging with tags was performed 2 weeks before and 2, 8, and 16 weeks after MI. The left and right ventricular volumes were measured, and regurgitant volume indexed to body surface area (regurgitant volume index) was calculated as the difference between left ventricle and right ventricle stroke volumes divided by body surface area. Three-dimensional strain was calculated. RESULTS Circumferential strain (Ecc) and longitudinal strain (Ell) were reduced in the infarct proper, MI borderzone, and remote myocardium 16 weeks after MI. In addition, radial circumferential (Erc) and radial longitudinal (Erl) shear strains were reduced in remote myocardium but increased in the infarct and borderzone 16 weeks after MI. Of all strain components, however, only Erc was affected by regurgitant volume index (p = 0.0005). There was no statistically significant effect of regurgitant volume index on Ecc, Ell, Erl, or circumferential longitudinal shear strain (Ecl). CONCLUSIONS Moderate CIMR alters radial circumferential shear strain after posterolateral MI in sheep. Further studies are needed to determine the effect of shear strain on myocyte hypertrophy and the effect of mitral repair on myocardial strain.
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Affiliation(s)
- Liang Ge
- Department of Surgery, University of California, San Francisco, California; Department of Bioengineering, University of California, San Francisco, California; Veterans Affairs Medical Center, San Francisco, California
| | - Yife Wu
- Veterans Affairs Medical Center, San Francisco, California
| | | | | | - Kiyoaki Takaba
- Veterans Affairs Medical Center, San Francisco, California
| | | | - Zhihong Zhang
- Veterans Affairs Medical Center, San Francisco, California
| | - Gabriel Acevedo-Bolton
- Department of Radiology, University of California, San Francisco, California; Veterans Affairs Medical Center, San Francisco, California
| | - David A Saloner
- Department of Radiology, University of California, San Francisco, California; Veterans Affairs Medical Center, San Francisco, California
| | - Arthur W Wallace
- Department of Anesthesia, University of California, San Francisco, California; Veterans Affairs Medical Center, San Francisco, California
| | - Rakesh Mishra
- Department of Medicine, University of California, San Francisco, California; Veterans Affairs Medical Center, San Francisco, California
| | - Eugene A Grossi
- Department of Cardiothoracic Surgery, New York University School of Medicine, New York, New York
| | - Julius M Guccione
- Department of Surgery, University of California, San Francisco, California; Department of Bioengineering, University of California, San Francisco, California; Veterans Affairs Medical Center, San Francisco, California
| | - Mark B Ratcliffe
- Department of Surgery, University of California, San Francisco, California; Department of Bioengineering, University of California, San Francisco, California; Veterans Affairs Medical Center, San Francisco, California.
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13
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Sarin EL, Shi W, Duara R, Melone TA, Kalra K, Strong A, Girish A, McIver BV, Thourani VH, Guyton RA, Padala M. Swine (Sus scrofa) as a Model of Postinfarction Mitral Regurgitation and Techniques to Accommodate Its Effects during Surgical Repair. Comp Med 2016; 66:290-299. [PMID: 27538860 PMCID: PMC4983171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 01/05/2016] [Accepted: 01/22/2016] [Indexed: 06/06/2023]
Abstract
Mitral regurgitation (MR) is a common heart-valve lesion after myocardial infarction in humans. Because it is considered a risk factor for accelerated heart failure and death, various surgical approaches and catheter-based devices to correct it are in development. Lack of a reproducible animal model of MR after myocardial infarction and reliable techniques to perform open-heart surgery in these diseased models led to the use of healthy animals to test new devices. Thus, most devices that are deemed safe in healthy animals have shown poor results in human efficacy studies, hampering progress in this area of research. Here we report our experience with a swine model of postinfarction MR, describe techniques to induce regurgitation and perform open-heart surgery in these diseased animals, and discuss our outcomes, complications, and solutions.
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Affiliation(s)
- Eric L Sarin
- Structural Heart Disease Research and Innovation Laboratory, Division of Cardiothoracic Surgery, Carlyle Fraser Heart Center, Emory University, Atlanta, Georgia, USA
| | - Weiwei Shi
- Structural Heart Disease Research and Innovation Laboratory, Division of Cardiothoracic Surgery, Carlyle Fraser Heart Center, Emory University, Atlanta, Georgia, USA
| | - Rajnish Duara
- Structural Heart Disease Research and Innovation Laboratory, Division of Cardiothoracic Surgery, Carlyle Fraser Heart Center, Emory University, Atlanta, Georgia, USA
| | - Todd A Melone
- Cardiac Perfusion Services, Emory Healthcare, Atlanta, Georgia, USA
| | - Kanika Kalra
- Structural Heart Disease Research and Innovation Laboratory, Division of Cardiothoracic Surgery, Carlyle Fraser Heart Center, Emory University, Atlanta, Georgia, USA
| | - Ashley Strong
- Structural Heart Disease Research and Innovation Laboratory, Division of Cardiothoracic Surgery, Carlyle Fraser Heart Center, Emory University, Atlanta, Georgia, USA
| | - Apoorva Girish
- Structural Heart Disease Research and Innovation Laboratory, Division of Cardiothoracic Surgery, Carlyle Fraser Heart Center, Emory University, Atlanta, Georgia, USA
| | - Bryant V McIver
- Structural Heart Disease Research and Innovation Laboratory, Division of Cardiothoracic Surgery, Carlyle Fraser Heart Center, Emory University, Atlanta, Georgia, USA
| | - Vinod H Thourani
- Structural Heart Disease Research and Innovation Laboratory, Division of Cardiothoracic Surgery, Carlyle Fraser Heart Center, Emory University, Atlanta, Georgia, USA
| | - Robert A Guyton
- Structural Heart Disease Research and Innovation Laboratory, Division of Cardiothoracic Surgery, Carlyle Fraser Heart Center, Emory University, Atlanta, Georgia, USA
| | - Muralidhar Padala
- Structural Heart Disease Research and Innovation Laboratory, Division of Cardiothoracic Surgery, Carlyle Fraser Heart Center, Emory University, Atlanta, Georgia, USA.
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Zeng X, Zou L, Levine RA, Guerrero JL, Handschumacher MD, Sullivan SM, Braithwaite GJC, Stone JR, Solis J, Muratoglu OK, Vlahakes GJ, Hung J. Efficacy of polymer injection for ischemic mitral regurgitation: persistent reduction of mitral regurgitation and attenuation of left ventricular remodeling. JACC Cardiovasc Interv 2015; 8:355-363. [PMID: 25596792 DOI: 10.1016/j.jcin.2014.09.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 09/22/2014] [Accepted: 09/25/2014] [Indexed: 11/27/2022]
Abstract
OBJECTIVES The aim of this study was to examine the chronic effects of polyvinyl-alcohol (PVA) injection on mitral regurgitation (MR) reduction, mitral valve geometry, and left ventricular (LV) remodeling in a chronic ischemic MR sheep model. BACKGROUND Previous studies have demonstrated acute efficacy of PVA hydrogel polymer injection into infarcted myocardium underlying the papillary muscle to relieve MR by papillary muscle repositioning. However, the chronic efficacy of PVA injection in the chronic infarction setting remains unclear. METHODS Sixteen sheep developed chronic MR 8 weeks after induced inferoposterior myocardial infarction. Ten consecutive sheep underwent PVA injection (PVA group) and 6 sheep served as control subjects with saline injection. Epicardial 2-/3-dimensional echocardiography was performed at the baseline, chronic MR (pre-injection), and sacrifice (8 weeks after injection) stages. RESULTS Both groups were comparable at the baseline and chronic MR stages. At sacrifice, MR decreased from moderate to trace or mild (vena contracta: 0.17 ± 0.08 cm vs. 0.56 ± 0.10 cm, p < 0.001) in the PVA group but progressed to moderate to severe in the control group. End-systolic and -diastolic volumes remained stable in the PVA group but increased significantly in the control group (both p < 0.05). At sacrifice, compared with the control group, the PVA group had significantly less left ventricular remodeling (end-systolic volume: 41.1 ± 10.4 ml vs. 55.9 ± 12.4 ml, p < 0.05), lower MR severity (vena contracta: 0.17 ± 0.08 cm vs. 0.60 ± 0.14 cm, p < 0.01), and favorable changes in mitral valve geometry. CONCLUSIONS Polymer injection in a chronic ischemic MR model results in persistent reduction of MR and attenuation of continued left ventricular remodeling over 8 weeks of follow-up.
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Affiliation(s)
- Xin Zeng
- Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Boston, Massachusetts
| | - Lin Zou
- Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Boston, Massachusetts
| | - Robert A Levine
- Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Boston, Massachusetts
| | - J Luis Guerrero
- Cardiac Surgery Division, Massachusetts General Hospital, Boston, Massachusetts
| | - Mark D Handschumacher
- Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Boston, Massachusetts
| | - Suzanne M Sullivan
- Cardiac Surgery Division, Massachusetts General Hospital, Boston, Massachusetts
| | | | - James R Stone
- Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts
| | - Jorge Solis
- Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Boston, Massachusetts
| | - Orhun K Muratoglu
- Biomaterials Laboratory, Department of Orthopedic Surgery, Massachusetts General Hospital, Boston, Massachusetts
| | - Gus J Vlahakes
- Cardiac Surgery Division, Massachusetts General Hospital, Boston, Massachusetts
| | - Judy Hung
- Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Boston, Massachusetts.
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Pantoja JL, Ge L, Zhang Z, Morrel WG, Guccione JM, Grossi EA, Ratcliffe MB. Posterior papillary muscle anchoring affects remote myofiber stress and pump function: finite element analysis. Ann Thorac Surg 2014; 98:1355-62. [PMID: 25130075 PMCID: PMC6051352 DOI: 10.1016/j.athoracsur.2014.04.077] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 04/14/2014] [Accepted: 04/15/2014] [Indexed: 11/17/2022]
Abstract
BACKGROUND The role of posterior papillary muscle anchoring (PPMA) in the management of chronic ischemic mitral regurgitation (CIMR) is controversial. We studied the effect of anchoring point direction and relocation displacement on left ventricular (LV) regional myofiber stress and pump function. METHODS Previously described finite element models of sheep 16 weeks after posterolateral myocardial infarction (MI) were used. True-sized mitral annuloplasty (MA) ring insertion plus different PPM anchoring techniques were simulated. Anchoring points tested included both commissures and the central anterior mitral annulus; relocation displacement varied from 10% to 40% of baseline diastolic distance from the PPM to the anchor points on the annulus. For each reconstruction scenario, myofiber stress in the MI, border zone, and remote myocardium as well as pump function were calculated. RESULTS PPMA caused reductions in myofiber stress at end-diastole and end-systole in all regions of the left ventricle that were proportional to the relocation displacement. Although stress reduction was greatest in the MI region, it also occurred in the remote region. The maximum 40% displacement caused a slight reduction in LV pump function. However, with the correction of regurgitation by MA plus PPMA, there was an overall increase in forward stroke volume. Finally, anchoring point direction had no effect on myofiber stress or pump function. CONCLUSIONS PPMA reduces remote myofiber stress, which is proportional to the absolute distance of relocation and independent of anchoring point. Aggressive use of PPMA techniques to reduce remote myofiber stress may accelerate reverse LV remodeling without impairing LV function.
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Affiliation(s)
- Joe Luis Pantoja
- School of Medicine, University of California, San Francisco, San Francisco, California
| | - Liang Ge
- Department of Surgery, University of California, San Francisco, San Francisco, California; Department of Bioengineering, University of California, San Francisco, San Francisco, California; Veterans Affairs Medical Center, San Francisco, California
| | - Zhihong Zhang
- Veterans Affairs Medical Center, San Francisco, California
| | - William G Morrel
- School of Medicine, University of California, San Francisco, San Francisco, California
| | - Julius M Guccione
- Department of Surgery, University of California, San Francisco, San Francisco, California; Department of Bioengineering, University of California, San Francisco, San Francisco, California; Veterans Affairs Medical Center, San Francisco, California
| | - Eugene A Grossi
- Department of Cardiothoracic Surgery, New York University, New York, New York; New York Harbor Veterans Affairs Medical Center, New York, New York
| | - Mark B Ratcliffe
- Department of Surgery, University of California, San Francisco, San Francisco, California; Department of Bioengineering, University of California, San Francisco, San Francisco, California; Veterans Affairs Medical Center, San Francisco, California.
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Beaudoin J, Levine RA, Guerrero JL, Yosefy C, Sullivan S, Abedat S, Handschumacher MD, Szymanski C, Gilon D, Palmeri NO, Vlahakes GJ, Hajjar RJ, Beeri R. Late repair of ischemic mitral regurgitation does not prevent left ventricular remodeling: importance of timing for beneficial repair. Circulation 2013; 128:S248-52. [PMID: 24030415 DOI: 10.1161/circulationaha.112.000124] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
BACKGROUND Ischemic mitral regurgitation (MR) is a frequent complication of myocardial infarction associated with left ventricular (LV) dilatation and dysfunction, which doubles mortality. At the molecular level, moderate ischemic MR is characterized by a biphasic response, with initial compensatory rise in prohypertrophic and antiapoptotic signals, followed by their exhaustion. We have shown that early MR repair 30 days after myocardial infarction is associated with LV reverse remodeling. It is not known whether MR repair performed after the exhaustion of compensatory mechanisms is also beneficial. We hypothesized that late repair will not result in LV reverse remodeling. METHODS AND RESULTS Twelve sheep underwent distal left anterior descending coronary artery ligation to create apical myocardial infarction and implantation of an LV-to-left atrium shunt to create standardized moderate volume overload. At 90 days, animals were randomized to shunt closure (late repair) versus sham (no repair). LV remodeling was assessed by 3-dimensional echocardiography, dP/dt, preload-recruitable stroke work, and myocardial biopsies. At 90 days, animals had moderate volume overload, LV dilatation, and reduced ejection fraction (all P<0.01 versus baseline, P=NS between groups). Shunt closure at 90 days corrected the volume overload (regurgitant fraction 6 ± 5% versus 27 ± 16% for late repair versus sham, P<0.01) but was not associated with changes in LV volumes (end-diastolic volume 106 ± 15 versus 110 ± 22 mL; end-systolic volume 35 ± 6 versus 36 ± 6 mL) or increases in preload-recruitable stroke work (41 ± 7 versus 39 ± 13 mL mm Hg) or dP/dt (803 ± 210 versus 732 ± 194 mm Hg/s) at 135 days (all P=NS). Activated Akt, central in the hypertrophic process, and signal transducer and activator of transcription 3 (STAT3), a critical node in the hypertrophic stimulus by cytokines, were equally depressed in both groups. CONCLUSIONS Late correction of moderate volume overload after myocardial infarction did not improve LV volume or contractility. Upregulation of prohypertrophic intracellular pathways was not observed. This contrasts with previously reported study in which early repair (30 days) reversed LV remodeling. This suggests a window of opportunity to repair ischemic MR after which no beneficial effect on LV is observed, despite successful repair.
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Affiliation(s)
- Jonathan Beaudoin
- Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, MA (J.B., R.A.L., J.L.G., C.Y., S.S., M.D.H., C.S., N.O.P., G.J.V., R.B.); Cardiovascular Research Center, Heart Institute, Hadassah-Hebrew University Medical Center, Ein-Karem, Jerusalem, Israel (S.A., D.G., R.B.); and Cardiovascular Research Center, Cardiovascular Institute, Mt Sinai School of Medicine, New York, NY (R.J.H.)
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Zhang C, Wang G, Wang J, Ji Z, Liu Z, Pi X, Chen C. Characterization and comparative analyses of muscle transcriptomes in Dorper and small-tailed Han sheep using RNA-Seq technique. PLoS One 2013; 8:e72686. [PMID: 24023632 PMCID: PMC3758325 DOI: 10.1371/journal.pone.0072686] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 07/17/2013] [Indexed: 02/02/2023] Open
Abstract
The sheep is an important domestic animal and model for many types of medically relevant research. An investigation of gene expression in ovine muscle would significantly advance our understanding of muscle growth. RNA-seq is a recently developed analytical approach for transcriptome profiling via high-throughput sequencing. Although RNA-seq has been recently applied to a wide variety of organisms, few RNA-seq studies have been conducted in livestock, particularly in sheep. In this study, two cDNA libraries were constructed from the biceps brachii of one Small-tailed Han sheep (SH) and one Dorper sheep (DP). The Illumina high-throughput sequencing technique and bioinformatics were used to determine transcript abundances and characteristics. For the SH and DP libraries, we obtained a total of 50,264,608 and 52,794,216 high quality reads, respectively. Approximately two-thirds of the reads could be mapped to the sheep genome. In addition, 40,481 and 38,851 potential coding single nucleotide polymorphisms (cSNPs) were observed, respectively, of which a total of 59,139 cSNP coordinates were different between the two samples. Up to 5,116 and 5,265 respective reference genes had undergone 13,827 and 15,684 alternative splicing events. A total of 6,989 reference genes were extended at the 5’, 3’ or both ends, and 123,678 novel transcript units were found. A total of 1,300 significantly differentially expressed genes were identified between the two libraries. These results suggest that there are many differences in the muscle transcriptomes between these two animals. This study addresses a preliminary analysis and offers a foundation for future genomic research in the sheep.
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Affiliation(s)
- Chunlan Zhang
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, Shandong Province, China
| | - Guizhi Wang
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, Shandong Province, China
| | - Jianmin Wang
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, Shandong Province, China
- * E-mail:
| | - Zhibin Ji
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, Shandong Province, China
| | - Zhaohuan Liu
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, Shandong Province, China
| | - Xiushuang Pi
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, Shandong Province, China
| | - Cunxian Chen
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, Shandong Province, China
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Li T, Wei X, Watkins AC, Sanchez PG, Wu ZJ, Griffith BP. Prophylactic amiodarone and lidocaine improve survival in an ovine model of large size myocardial infarction. J Surg Res 2013; 185:152-8. [PMID: 23773712 DOI: 10.1016/j.jss.2013.05.050] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Revised: 04/26/2013] [Accepted: 05/10/2013] [Indexed: 10/26/2022]
Abstract
BACKGROUND Large animal models serve as a critical link in the translation of basic science to clinical practice. However, large animal models of myocardial infarction (MI), especially large size MI, have been associated with high mortality because of arrhythmia. The prophylactic effect of amiodarone and lidocaine were retrospectively reviewed in our ovine MI model. MATERIALS AND METHODS A total of 114 Dorset hybrid sheep with 25%-30% MI were included in the present study. The sheep were prophylactically treated with amiodarone plus lidocaine before ligation of the four to six coronary artery branches supplying the apex of the heart (arrhythmia prevention [AP] group, n = 45) and with epinephrine (shock prevention [SP] group, n = 49), respectively. The sheep without prophylactic treatment (no prevention [NP] group, n = 20) were used as the control group. The incidence of arrhythmia requiring treatment, mortality due to arrhythmia, hemodynamics, and arterial blood gas values during surgery were analyzed in these three groups. RESULTS No significant difference was found in infarct size among the three groups. The incidence of arrhythmia requiring treatment was significantly decreased in the AP group compared with that in the NP or SP groups (4.4% for AP versus 35% for NP and 45% for SP groups; P < 0.05). The mortality due to lethal arrhythmia was 2.2% in the AP group, significantly lower than that in the NP group (15%) or SP group (18.4%). Other than the heart rate, no significant differences were found in the hemodynamic data between the AP and NP groups. Metabolic acidosis was not observed in any group, as indicated by the pH and lactate values. CONCLUSIONS Prophylactic amiodarone plus lidocaine decreased the mortality due to lethal arrhythmia after acute MI in our sheep model without significant negative effects on the hemodynamics. However, epinephrine improved the hemodynamics but also increased the mortality due to lethal arrhythmia. Thus, prophylactic amiodarone plus lidocaine is recommended to improve the stability in a large MI animal model.
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Affiliation(s)
- Tieluo Li
- Division of Cardiac Surgery, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland
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Szymanski C, Messas E. Ischemic mitral regurgitation: New concepts. Arch Cardiovasc Dis 2013; 106:183-7. [DOI: 10.1016/j.acvd.2013.03.058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Accepted: 03/04/2013] [Indexed: 10/26/2022]
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Moderate mitral regurgitation accelerates left ventricular remodeling after posterolateral myocardial infarction. Ann Thorac Surg 2011; 92:1614-20. [PMID: 21945222 DOI: 10.1016/j.athoracsur.2011.05.117] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Revised: 05/25/2011] [Accepted: 05/31/2011] [Indexed: 01/06/2023]
Abstract
BACKGROUND Chronic ischemic mitral regurgitation (MR) is associated with poor outcome. However, the effect of chronic ischemic MR on left ventricular (LV) remodeling after posterolateral myocardial infarction (MI) remains controversial. We tested the hypothesis that moderate MR accelerates LV remodeling after posterolateral MI. METHODS Posterolateral MI was created in 10 sheep. Cardiac magnetic resonance imaging was performed 2 weeks before and 2, 8, and 16 weeks after MI. Left ventricular and right ventricular volumes were measured, and regurgitant volume was calculated as the difference between LV and right ventricle stroke volumes. RESULTS Multivariate mixed effects regression showed that LV volumes at end diastole and end systole and LV sphericity were strongly correlated with both regurgitant volume (p < 0.0001, p = 0.0086, and p = 0.0007, respectively) and percent infarct area (p = 0.0156, p = 0.0307, and p < 0.0001, respectively). Conversely, whereas LV hypertrophy (LV wall volume) increased from 2 weeks to 16 weeks after MI, there was no effect of either regurgitant volume or percent infarct. CONCLUSIONS Moderate MR accelerates LV remodeling after posterolateral MI. Further studies are needed to determine whether mitral valve repair is able to slow or reverse MI remodeling after posterolateral MI.
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Jäger M, Ott CE, Grünhagen J, Hecht J, Schell H, Mundlos S, Duda GN, Robinson PN, Lienau J. Composite transcriptome assembly of RNA-seq data in a sheep model for delayed bone healing. BMC Genomics 2011; 12:158. [PMID: 21435219 PMCID: PMC3074554 DOI: 10.1186/1471-2164-12-158] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Accepted: 03/24/2011] [Indexed: 11/28/2022] Open
Abstract
Background The sheep is an important model organism for many types of medically relevant research, but molecular genetic experiments in the sheep have been limited by the lack of knowledge about ovine gene sequences. Results Prior to our study, mRNA sequences for only 1,556 partial or complete ovine genes were publicly available. Therefore, we developed a composite de novo transcriptome assembly method for next-generation sequence data to combine known ovine mRNA and EST sequences, mRNA sequences from mouse and cow, and sequences assembled de novo from short read RNA-Seq data into a composite reference transcriptome, and identified transcripts from over 12 thousand previously undescribed ovine genes. Gene expression analysis based on these data revealed substantially different expression profiles in standard versus delayed bone healing in an ovine tibial osteotomy model. Hundreds of transcripts were differentially expressed between standard and delayed healing and between the time points of the standard and delayed healing groups. We used the sheep sequences to design quantitative RT-PCR assays with which we validated the differential expression of 26 genes that had been identified by RNA-seq analysis. A number of clusters of characteristic expression profiles could be identified, some of which showed striking differences between the standard and delayed healing groups. Gene Ontology (GO) analysis showed that the differentially expressed genes were enriched in terms including extracellular matrix, cartilage development, contractile fiber, and chemokine activity. Conclusions Our results provide a first atlas of gene expression profiles and differentially expressed genes in standard and delayed bone healing in a large-animal model and provide a number of clues as to the shifts in gene expression that underlie delayed bone healing. In the course of our study, we identified transcripts of 13,987 ovine genes, including 12,431 genes for which no sequence information was previously available. This information will provide a basis for future molecular research involving the sheep as a model organism.
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Affiliation(s)
- Marten Jäger
- Institute for Medical Genetics, Charité-Universitätsmedizin Berlin, Augustenburgerplatz 1, 13353 Berlin, Germany
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Bibliography--Editors' selection of current word literature. Coron Artery Dis 2010; 21:486-8. [PMID: 21076239 DOI: 10.1097/mca.0b013e328341d225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Grossi EA, Galloway AC. Invited commentary. Ann Thorac Surg 2010; 90:794-5. [PMID: 20732498 DOI: 10.1016/j.athoracsur.2010.04.048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Revised: 04/12/2010] [Accepted: 04/15/2010] [Indexed: 10/19/2022]
Affiliation(s)
- Eugene A Grossi
- New York University School of Medicine, New York University Medical Center, 530 First Ave, Ste 9V, New York, NY 10016, USA.
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