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Mukherjee T, Usman M, Mehdi RR, Mendiola E, Ohayon J, Lindquist D, Shah D, Sadayappan S, Pettigrew R, Avazmohammadi R. In-silico heart model phantom to validate cardiac strain imaging. Comput Biol Med 2024; 181:109065. [PMID: 39217965 DOI: 10.1016/j.compbiomed.2024.109065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 08/15/2024] [Accepted: 08/20/2024] [Indexed: 09/04/2024]
Abstract
The quantification of cardiac strains as structural indices of cardiac function has a growing prevalence in clinical diagnosis. However, the highly heterogeneous four-dimensional (4D) cardiac motion challenges accurate "regional" strain quantification and leads to sizable differences in the estimated strains depending on the imaging modality and post-processing algorithm, limiting the translational potential of strains as incremental biomarkers of cardiac dysfunction. There remains a crucial need for a feasible benchmark that successfully replicates complex 4D cardiac kinematics to determine the reliability of strain calculation algorithms. In this study, we propose an in-silico heart phantom derived from finite element (FE) simulations to validate the quantification of 4D regional strains. First, as a proof-of-concept exercise, we created synthetic magnetic resonance (MR) images for a hollow thick-walled cylinder under pure torsion with an exact solution and demonstrated that "ground-truth" values can be recovered for the twist angle, which is also a key kinematic index in the heart. Next, we used mouse-specific FE simulations of cardiac kinematics to synthesize dynamic MR images by sampling various sectional planes of the left ventricle (LV). Strains were calculated using our recently developed non-rigid image registration (NRIR) framework in both problems. Moreover, we studied the effects of image quality on distorting regional strain calculations by conducting in-silico experiments for various LV configurations. Our studies offer a rigorous and feasible tool to standardize regional strain calculations to improve their clinical impact as incremental biomarkers.
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Affiliation(s)
- Tanmay Mukherjee
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Muhammad Usman
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Rana Raza Mehdi
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Emilio Mendiola
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Jacques Ohayon
- Savoie Mont-Blanc University, Polytech Annecy-Chambéry, Le Bourget du Lac, France; Laboratory TIMC-CNRS, UMR 5525, Grenoble-Alpes University, Grenoble, France
| | - Diana Lindquist
- Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Dipan Shah
- Houston Methodist DeBakey Heart and Vascular Center, Houston, TX, 77030, USA
| | - Sakthivel Sadayappan
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Roderic Pettigrew
- School of Engineering Medicine, Texas A&M University, Houston, TX 77030, USA; Department of Cardiovascular Sciences, Houston Methodist Academic Institute, Houston, TX 77030, USA
| | - Reza Avazmohammadi
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA; Department of Cardiovascular Sciences, Houston Methodist Academic Institute, Houston, TX 77030, USA; J. Mike Walker '66 Department of Mechanical Engineering, Texas A&M University, College Station, TX 77843, USA.
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2
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Mukherjee T, Usman M, Mehdi RR, Mendiola E, Ohayon J, Lindquist D, Shah D, Sadayappan S, Pettigrew R, Avazmohammadi R. In-silico heart model phantom to validate cardiac strain imaging. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.05.606672. [PMID: 39149320 PMCID: PMC11326205 DOI: 10.1101/2024.08.05.606672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
The quantification of cardiac strains as structural indices of cardiac function has a growing prevalence in clinical diagnosis. However, the highly heterogeneous four-dimensional (4D) cardiac motion challenges accurate "regional" strain quantification and leads to sizable differences in the estimated strains depending on the imaging modality and post-processing algorithm, limiting the translational potential of strains as incremental biomarkers of cardiac dysfunction. There remains a crucial need for a feasible benchmark that successfully replicates complex 4D cardiac kinematics to determine the reliability of strain calculation algorithms. In this study, we propose an in-silico heart phantom derived from finite element (FE) simulations to validate the quantification of 4D regional strains. First, as a proof-of-concept exercise, we created synthetic magnetic resonance (MR) images for a hollow thick-walled cylinder under pure torsion with an exact solution and demonstrated that "ground-truth" values can be recovered for the twist angle, which is also a key kinematic index in the heart. Next, we used mouse-specific FE simulations of cardiac kinematics to synthesize dynamic MR images by sampling various sectional planes of the left ventricle (LV). Strains were calculated using our recently developed non-rigid image registration (NRIR) framework in both problems. Moreover, we studied the effects of image quality on distorting regional strain calculations by conducting in-silico experiments for various LV configurations. Our studies offer a rigorous and feasible tool to standardize regional strain calculations to improve their clinical impact as incremental biomarkers.
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Affiliation(s)
- Tanmay Mukherjee
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Muhammad Usman
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Rana Raza Mehdi
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Emilio Mendiola
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Jacques Ohayon
- Savoie Mont-Blanc University, Polytech Annecy-Chambéry, Le Bourget du Lac, France
- Laboratory TIMC-CNRS, UMR 5525, Grenoble-Alpes University, Grenoble, France
| | - Diana Lindquist
- Department of Radiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Dipan Shah
- Houston Methodist DeBakey Heart and Vascular Center, Houston, TX, 77030, USA
| | - Sakthivel Sadayappan
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Roderic Pettigrew
- School of Engineering Medicine, Texas A&M University, Houston, TX 77030, USA
- Department of Cardiovascular Sciences, Houston Methodist Academic Institute, Houston, TX 77030, USA
| | - Reza Avazmohammadi
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
- Department of Cardiovascular Sciences, Houston Methodist Academic Institute, Houston, TX 77030, USA
- J. Mike Walker ’66 Department of Mechanical Engineering, Texas A&M University, College Station, TX 77843, USA
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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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4
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Chen Z, Lin Z, Obaid SN, Rytkin E, George SA, Bach C, Madrid M, Liu M, LaPiano J, Fehr A, Shi X, Quirion N, Russo B, Knight H, Aduwari A, Efimov IR, Lu L. Soft, bioresorbable, transparent microelectrode arrays for multimodal spatiotemporal mapping and modulation of cardiac physiology. SCIENCE ADVANCES 2023; 9:eadi0757. [PMID: 37406128 DOI: 10.1126/sciadv.adi0757] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Accepted: 06/01/2023] [Indexed: 07/07/2023]
Abstract
Transparent microelectrode arrays (MEAs) that allow multimodal investigation of the spatiotemporal cardiac characteristics are important in studying and treating heart disease. Existing implantable devices, however, are designed to support chronic operational lifetimes and require surgical extraction when they malfunction or are no longer needed. Meanwhile, bioresorbable systems that can self-eliminate after performing temporary functions are increasingly attractive because they avoid the costs/risks of surgical extraction. We report the design, fabrication, characterization, and validation of a soft, fully bioresorbable, and transparent MEA platform for bidirectional cardiac interfacing over a clinically relevant period. The MEA provides multiparametric electrical/optical mapping of cardiac dynamics and on-demand site-specific pacing to investigate and treat cardiac dysfunctions in rat and human heart models. The bioresorption dynamics and biocompatibility are investigated. The device designs serve as the basis for bioresorbable cardiac technologies for potential postsurgical monitoring and treating temporary patient pathological conditions in certain clinical scenarios, such as myocardial infarction, ischemia, and transcatheter aortic valve replacement.
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Affiliation(s)
- Zhiyuan Chen
- Department of Biomedical Engineering, The George Washington University, Washington, DC 20052, USA
| | - Zexu Lin
- Department of Biomedical Engineering, The George Washington University, Washington, DC 20052, USA
| | - Sofian N Obaid
- Department of Biomedical Engineering, The George Washington University, Washington, DC 20052, USA
| | - Eric Rytkin
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Sharon A George
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Christopher Bach
- Department of Biomedical Engineering, The George Washington University, Washington, DC 20052, USA
| | - Micah Madrid
- Department of Biomedical Engineering, The George Washington University, Washington, DC 20052, USA
| | - Miya Liu
- Department of Biomedical Engineering, The George Washington University, Washington, DC 20052, USA
| | - Jessica LaPiano
- MedStar Georgetown University Hospital, Washington, DC 20037, USA
| | - Amy Fehr
- Department of Biomedical Engineering, The George Washington University, Washington, DC 20052, USA
| | - Xinyu Shi
- Department of Biomedical Engineering, The George Washington University, Washington, DC 20052, USA
| | - Nathaniel Quirion
- Department of Biomedical Engineering, The George Washington University, Washington, DC 20052, USA
| | - Benjamin Russo
- Department of Biomedical Engineering, The George Washington University, Washington, DC 20052, USA
| | - Helen Knight
- Department of Biomedical Engineering, The George Washington University, Washington, DC 20052, USA
| | - Anthony Aduwari
- Department of Biomedical Engineering, The George Washington University, Washington, DC 20052, USA
| | - Igor R Efimov
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
- Department of Medicine (Cardiology), Northwestern University, Chicago, IL 60611, USA
| | - Luyao Lu
- Department of Biomedical Engineering, The George Washington University, Washington, DC 20052, USA
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5
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Miller JM, Meki MH, Elnakib A, Ou Q, Abouleisa RRE, Tang XL, Salama ABM, Gebreil A, Lin C, Abdeltawab H, Khalifa F, Hill BG, Abi-Gerges N, Bolli R, El-Baz AS, Giridharan GA, Mohamed TMA. Biomimetic cardiac tissue culture model (CTCM) to emulate cardiac physiology and pathophysiology ex vivo. Commun Biol 2022; 5:934. [PMID: 36085302 PMCID: PMC9463130 DOI: 10.1038/s42003-022-03919-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 08/30/2022] [Indexed: 11/23/2022] Open
Abstract
There is need for a reliable in vitro system that can accurately replicate the cardiac physiological environment for drug testing. The limited availability of human heart tissue culture systems has led to inaccurate interpretations of cardiac-related drug effects. Here, we developed a cardiac tissue culture model (CTCM) that can electro-mechanically stimulate heart slices with physiological stretches in systole and diastole during the cardiac cycle. After 12 days in culture, this approach partially improved the viability of heart slices but did not completely maintain their structural integrity. Therefore, following small molecule screening, we found that the incorporation of 100 nM tri-iodothyronine (T3) and 1 μM dexamethasone (Dex) into our culture media preserved the microscopic structure of the slices for 12 days. When combined with T3/Dex treatment, the CTCM system maintained the transcriptional profile, viability, metabolic activity, and structural integrity for 12 days at the same levels as the fresh heart tissue. Furthermore, overstretching the cardiac tissue induced cardiac hypertrophic signaling in culture, which provides a proof of concept for the ability of the CTCM to emulate cardiac stretch-induced hypertrophic conditions. In conclusion, CTCM can emulate cardiac physiology and pathophysiology in culture for an extended time, thereby enabling reliable drug screening.
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Affiliation(s)
- Jessica M Miller
- From the Institute of Molecular Cardiology, Department of Medicine, University of Louisville, Louisville, USA
- Department of Bioengineering, University of Louisville, Louisville, USA
| | - Moustafa H Meki
- From the Institute of Molecular Cardiology, Department of Medicine, University of Louisville, Louisville, USA
- Department of Bioengineering, University of Louisville, Louisville, USA
| | - Ahmed Elnakib
- Department of Bioengineering, University of Louisville, Louisville, USA
| | - Qinghui Ou
- From the Institute of Molecular Cardiology, Department of Medicine, University of Louisville, Louisville, USA
| | - Riham R E Abouleisa
- From the Institute of Molecular Cardiology, Department of Medicine, University of Louisville, Louisville, USA
| | - Xian-Liang Tang
- From the Institute of Molecular Cardiology, Department of Medicine, University of Louisville, Louisville, USA
| | - Abou Bakr M Salama
- From the Institute of Molecular Cardiology, Department of Medicine, University of Louisville, Louisville, USA
- Faculty of Medicine, Zagazig University, Zagazig, Egypt
| | - Ahmad Gebreil
- From the Institute of Molecular Cardiology, Department of Medicine, University of Louisville, Louisville, USA
| | - Cindy Lin
- From the Institute of Molecular Cardiology, Department of Medicine, University of Louisville, Louisville, USA
| | - Hisham Abdeltawab
- Department of Bioengineering, University of Louisville, Louisville, USA
| | - Fahmi Khalifa
- Department of Bioengineering, University of Louisville, Louisville, USA
| | - Bradford G Hill
- Envirome Institute, Diabetes and Obesity Center, Department of Medicine, University of Louisville, Louisville, USA
| | | | - Roberto Bolli
- From the Institute of Molecular Cardiology, Department of Medicine, University of Louisville, Louisville, USA
| | - Ayman S El-Baz
- Department of Bioengineering, University of Louisville, Louisville, USA
| | | | - Tamer M A Mohamed
- From the Institute of Molecular Cardiology, Department of Medicine, University of Louisville, Louisville, USA.
- Department of Bioengineering, University of Louisville, Louisville, USA.
- Envirome Institute, Diabetes and Obesity Center, Department of Medicine, University of Louisville, Louisville, USA.
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, USA.
- Institute of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom.
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6
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Mohamed TMA, Moslehi J, Satin J. Editorial: Recent Advances in Cardiotoxicity Testing. Front Pharmacol 2021; 12:798189. [PMID: 34819868 PMCID: PMC8606750 DOI: 10.3389/fphar.2021.798189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 10/26/2021] [Indexed: 11/13/2022] Open
Affiliation(s)
- Tamer M A Mohamed
- Department of Medicine, The Institute of Molecular Cardiology, University of Louisville, Louisville, KY, United States.,Department of Medicine, Diabetes and Obesity Center, Envirome Institute, University of Louisville, Louisville, KY, United States
| | - Javid Moslehi
- Department of Cardio-oncology, University of California, San Francisco, San Francisco, CA, United States
| | - Jonathan Satin
- Department of Physiology, University of Kentucky, Lexington, KY, United States
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7
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Meki MH, Miller JM, Mohamed TMA. Heart Slices to Model Cardiac Physiology. Front Pharmacol 2021; 12:617922. [PMID: 33613292 PMCID: PMC7890402 DOI: 10.3389/fphar.2021.617922] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 01/05/2021] [Indexed: 12/02/2022] Open
Abstract
Translational research in the cardiovascular field is hampered by the unavailability of cardiac models that can recapitulate organ-level physiology of the myocardium. Outside the body, cardiac tissue undergoes rapid dedifferentiation and maladaptation in culture. There is an ever-growing demand for preclinical platforms that allow for accurate, standardized, long-term, and rapid drug testing. Heart slices is an emerging technology that solves many of the problems with conventional myocardial culture systems. Heart slices are thin (<400 µm) slices of heart tissue from the adult ventricle. Several recent studies using heart slices have shown their ability to maintain the adult phenotype for prolonged periods in a multi cell-type environment. Here, we review the current status of cardiac culture systems and highlight the unique advantages offered by heart slices in the light of recent efforts in developing physiologically relevant heart slice culture systems.
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Affiliation(s)
- Moustafa H Meki
- Institute of Molecular Cardiology, Department of Medicine, University of Louisville, Louisville, KY, United States.,Department of Bioengineering, University of Louisville, Louisville, KY, United States
| | - Jessica M Miller
- Institute of Molecular Cardiology, Department of Medicine, University of Louisville, Louisville, KY, United States.,Department of Bioengineering, University of Louisville, Louisville, KY, United States
| | - Tamer M A Mohamed
- Institute of Molecular Cardiology, Department of Medicine, University of Louisville, Louisville, KY, United States.,Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY, United States.,Institute of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
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8
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Ibrahim ESH, Baruah D, Budde M, Rubenstein J, Frei A, Schlaak R, Gore E, Bergom C. Optimized cardiac functional MRI of small-animal models of cancer radiation therapy. Magn Reson Imaging 2020; 73:130-137. [PMID: 32866598 DOI: 10.1016/j.mri.2020.08.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 07/23/2020] [Accepted: 08/20/2020] [Indexed: 01/27/2023]
Abstract
Cardiac MRI of small animal models of cancer radiation therapy (RT) is a valuable tool for studying the effect of RT on the heart. However, standard cardiac MRI exams require long scanning times, which is challenging for sick animals that may not survive extended periods of imaging under anesthesia. The purpose of this study is to develop an optimized, fast MRI exam for comprehensive cardiac functional imaging of small-animal models of cancer RT. Ten adult female rats (2 non-irradiated and 8 irradiated) were scanned using the developed exam. Optimal imaging parameters were determined, which minimized scanning time while ensuring measurement accuracy and avoiding imaging artifacts. This optimized, fast MRI exam lasted for 30 min, which was tolerated by all animals. EF was normal in all imaged rats, although it was significantly increased in the irradiated rats, which also showed ventricular hypertrophy. However, myocardial strain was significantly reduced in the irradiated rats. In conclusion, a fast MRI exam has been developed for comprehensive cardiac functional imaging of rats in 30 min, with optimized imaging parameters to ensure accurate measurements and tolerance by irradiated rats. The generated strain measurements provide an early marker of regional cardiac dysfunction before global function is affected.
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Affiliation(s)
- El-Sayed H Ibrahim
- Medical College of Wisconsin, 8701 W Watertown Plank Rd, Milwaukee, WI 53226, USA.
| | - Dhiraj Baruah
- Medical College of Wisconsin, 8701 W Watertown Plank Rd, Milwaukee, WI 53226, USA.
| | - Matthew Budde
- Medical College of Wisconsin, 8701 W Watertown Plank Rd, Milwaukee, WI 53226, USA.
| | - Jason Rubenstein
- Medical College of Wisconsin, 8701 W Watertown Plank Rd, Milwaukee, WI 53226, USA.
| | - Anne Frei
- Medical College of Wisconsin, 8701 W Watertown Plank Rd, Milwaukee, WI 53226, USA.
| | - Rachel Schlaak
- Medical College of Wisconsin, 8701 W Watertown Plank Rd, Milwaukee, WI 53226, USA.
| | - Elizabeth Gore
- Medical College of Wisconsin, 8701 W Watertown Plank Rd, Milwaukee, WI 53226, USA.
| | - Carmen Bergom
- Medical College of Wisconsin, 8701 W Watertown Plank Rd, Milwaukee, WI 53226, USA; Washington University School of Medicine, 4511 Forest Park Ave, St. Louis, MI 63108, USA..
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9
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Yoshida K, Tanabe Y, Kido T, Kurata A, Uraoka D, Kinoshita M, Uetani T, Nishimura K, Inoue K, Ikeda S, Yamaguchi O, Mochizuki T. Characteristics of the left ventricular three-dimensional maximum principal strain using cardiac computed tomography: reference values from subjects with normal cardiac function. Eur Radiol 2020; 30:6109-6117. [PMID: 32556462 DOI: 10.1007/s00330-020-07001-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 04/15/2020] [Accepted: 06/03/2020] [Indexed: 01/01/2023]
Abstract
OBJECTIVES This study evaluated the characteristics of left ventricular maximum principal strain (LV-MPS) using cardiac CT in subjects with normal LV function. METHODS Of 973 subjects who underwent retrospective electrocardiogram-gated cardiac CT using a third-generation dual-source CT without beta-blocker administration, 31 subjects with preserved LV ejection fraction ≥ 55% assessed by echocardiography without coronary artery stenosis and cardiac pathology were retrospectively identified. CT images were reconstructed every 5% (0-95%) of the RR interval. LV-MPS and the time to peak (TTP) were analyzed using the 16-segment model and compared among three levels (base, mid, and apex) and among four regions (anterior, septum, inferior, and lateral) using the Steel-Dwass test. The intra- and inter-observer reproducibilities for LV-MPS were calculated using intraclass correlation coefficients (ICCs). RESULTS The intra- and inter-observer ICCs (95% confidence interval) for peak LV-MPS were 0.96 (0.94-0.97) and 0.94 (0.92-0.96), respectively. The global peak LV-MPS (median, inter-quantile range) was 0.59 (0.55-0.72). The regional LV-MPS significantly increased in the order of the basal (0.54, 0.49-0.59), mid-LV (0.57, 0.53-0.65), and apex (0.68, 0.60-0.84) (p < 0.05, in each), and was significantly higher in the lateral wall (0.66, 0.60-0.77), while that in the septal region (0.47, 0.44-0.54) was the lowest among the four LV regions (all p < 0.05). No significant difference in TTP was seen among the myocardial levels and regions. CONCLUSION CT-derived LV-MPS is reproducible and quantitatively represents synchronized myocardial contraction with heterogeneous values in subjects with normal LV function. KEY POINTS • CT-derived left ventricular maximum principal strain analysis allows highly reproducible quantitative assessments of left ventricular myocardial contraction. • In subjects with normal cardiac function, the peak value of CT-derived left ventricular maximum principal strain is the highest in the apical level and in the lateral wall and the lowest in the septum. • The regional peak left ventricular maximum principal strain shows intra-ventricular heterogeneity on a per-patient basis, but myocardial contraction is globally synchronized in subjects with normal cardiac function seen on cardiac CT.
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Affiliation(s)
- Kazuki Yoshida
- Department of Radiology, Ehime University Graduate School of Medicine, Shitsukawa, Toon City, Ehime, 791-0295, Japan
| | - Yuki Tanabe
- Department of Radiology, Ehime University Graduate School of Medicine, Shitsukawa, Toon City, Ehime, 791-0295, Japan.
| | - Teruhito Kido
- Department of Radiology, Ehime University Graduate School of Medicine, Shitsukawa, Toon City, Ehime, 791-0295, Japan
| | - Akira Kurata
- Department of Radiology, Ehime University Graduate School of Medicine, Shitsukawa, Toon City, Ehime, 791-0295, Japan
| | - Daichi Uraoka
- Department of Radiology, Ehime University Graduate School of Medicine, Shitsukawa, Toon City, Ehime, 791-0295, Japan
| | - Masaki Kinoshita
- Department of Cardiology, Pulmonology, Hypertension and Nephrology, Ehime University Graduate School of Medicine, Shitsukawa, Toon City, Ehime, 791-0295, Japan
| | - Teruyoshi Uetani
- Department of Cardiology, Pulmonology, Hypertension and Nephrology, Ehime University Graduate School of Medicine, Shitsukawa, Toon City, Ehime, 791-0295, Japan
| | - Kazuhisa Nishimura
- Department of Cardiology, Pulmonology, Hypertension and Nephrology, Ehime University Graduate School of Medicine, Shitsukawa, Toon City, Ehime, 791-0295, Japan
| | - Katsuji Inoue
- Department of Cardiology, Pulmonology, Hypertension and Nephrology, Ehime University Graduate School of Medicine, Shitsukawa, Toon City, Ehime, 791-0295, Japan
| | - Shuntaro Ikeda
- Department of Cardiology, Pulmonology, Hypertension and Nephrology, Ehime University Graduate School of Medicine, Shitsukawa, Toon City, Ehime, 791-0295, Japan
| | - Osamu Yamaguchi
- Department of Cardiology, Pulmonology, Hypertension and Nephrology, Ehime University Graduate School of Medicine, Shitsukawa, Toon City, Ehime, 791-0295, Japan
| | - Teruhito Mochizuki
- Department of Radiology, Ehime University Graduate School of Medicine, Shitsukawa, Toon City, Ehime, 791-0295, Japan
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10
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Long-term functional and structural preservation of precision-cut human myocardium under continuous electromechanical stimulation in vitro. Nat Commun 2019; 10:117. [PMID: 30631059 PMCID: PMC6328583 DOI: 10.1038/s41467-018-08003-1] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Accepted: 12/10/2018] [Indexed: 12/26/2022] Open
Abstract
In vitro models incorporating the complexity and function of adult human tissues are highly desired for translational research. Whilst vital slices of human myocardium approach these demands, their rapid degeneration in tissue culture precludes long-term experimentation. Here, we report preservation of structure and performance of human myocardium under conditions of physiological preload, compliance, and continuous excitation. In biomimetic culture, tissue slices prepared from explanted failing human hearts attain a stable state of contractility that can be monitored for up to 4 months or 2000000 beats in vitro. Cultured myocardium undergoes particular alterations in biomechanics, structure, and mRNA expression. The suitability of the model for drug safety evaluation is exemplified by repeated assessment of refractory period that permits sensitive analysis of repolarization impairment induced by the multimodal hERG-inhibitor pentamidine. Biomimetic tissue culture will provide new opportunities to study drug targets, gene functions, and cellular plasticity in adult human myocardium. Myocardial tissue undergoes steady functional decline when cultured in vitro. Here, the authors report a protocol for culture of human cardiac slices that allows maintenance of contractility for up to four months, and show that the model is suitable for evaluation of drug safety, as exemplified for drugs interfering with cardiomyocyte repolarization.
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Cooke S, Samuel TJ, Cooper SM, Stöhr EJ. Adaptation of myocardial twist in the remodelled athlete's heart is not related to cardiac output. Exp Physiol 2018; 103:1456-1468. [DOI: 10.1113/ep087165] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Accepted: 09/10/2018] [Indexed: 12/16/2022]
Affiliation(s)
- Samuel Cooke
- Discipline of Physiology & Health; Cardiff School of Sport & Health Sciences (Sport); Cardiff Metropolitan University; Cardiff UK
| | - T. Jake Samuel
- Discipline of Physiology & Health; Cardiff School of Sport & Health Sciences (Sport); Cardiff Metropolitan University; Cardiff UK
| | - Stephen-Mark Cooper
- Discipline of Physiology & Health; Cardiff School of Sport & Health Sciences (Sport); Cardiff Metropolitan University; Cardiff UK
| | - Eric J. Stöhr
- Discipline of Physiology & Health; Cardiff School of Sport & Health Sciences (Sport); Cardiff Metropolitan University; Cardiff UK
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Oliveira LFLD, O'Connell JL, Carvalho EEVD, Pulici ÉCC, Romano MMD, Maciel BC, Simões MV. Comparison between Radionuclide Ventriculography and Echocardiography for Quantification of Left Ventricular Systolic Function in Rats Exposed to Doxorubicin. Arq Bras Cardiol 2017; 108:12-20. [PMID: 28146205 PMCID: PMC5245843 DOI: 10.5935/abc.20160194] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Accepted: 06/28/2016] [Indexed: 12/11/2022] Open
Abstract
Background Radionuclide ventriculography (RV) is a validated method to evaluate the left
ventricular systolic function (LVSF) in small rodents. However, no prior
study has compared the results of RV with those obtained by other imaging
methods in this context. Objectives To compare the results of LVSF obtained by RV and echocardiography (ECHO) in
an experimental model of cardiotoxicity due to doxorubicin (DXR) in rats.
Methods Adult male Wistar rats serving as controls (n = 7) or receiving DXR (n = 22)
in accumulated doses of 8, 12, and 16 mg/kg were evaluated with ECHO
performed with a Sonos 5500 Philips equipment (12-MHz transducer) and RV
obtained with an Orbiter-Siemens gamma camera using a pinhole collimator
with a 4-mm aperture. Histopathological quantification of myocardial
fibrosis was performed after euthanasia. Results The control animals showed comparable results in the LVSF analysis obtained
with ECHO and RV (83.5 ± 5% and 82.8 ± 2.8%, respectively, p
> 0.05). The animals that received DXR presented lower LVSF values when
compared with controls (p < 0.05); however, the LVSF values obtained by
RV (60.6 ± 12.5%) were lower than those obtained by ECHO (71.8
± 10.1%, p = 0.0004) in this group. An analysis of the correlation
between the LVSF and myocardial fibrosis showed a moderate correlation when
the LVSF was assessed by ECHO (r = -0.69, p = 0.0002) and a stronger
correlation when it was assessed by RV (r = -0.79, p < 0.0001). On
multiple regression analysis, only RV correlated independently with
myocardial fibrosis. Conclusion RV is an alternative method to assess the left ventricular function in small
rodents in vivo. When compared with ECHO, RV showed a better correlation
with the degree of myocardial injury in a model of DXR-induced
cardiotoxicity.
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Affiliation(s)
| | | | | | | | | | - Benedito Carlos Maciel
- Centro de Cardiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Brazil
| | - Marcus Vinicius Simões
- Centro de Cardiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Brazil
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Masithulela F. Bi-ventricular finite element model of right ventricle overload in the healthy rat heart. Biomed Mater Eng 2016; 27:507-525. [PMID: 27885998 DOI: 10.3233/bme-161604] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND The recognition of RV overpressure is critical to human life, as this may signify morbidity and mortality. Right ventricle (RV) dysfunction is understood to have an impact on the performance of the left ventricle (LV), but the mechanisms remain poorly understood. It is understood that ventricular compliance has the ability to affect cardiac performance. In this study, a bi-ventricular model of the rat heart was used in preference to other, single-ventricle models. Finite element analysis (FEA) of the bi-ventricular model provides important information on the function of the healthy heart. METHODS The passive myocardium was modelled as a nearly incompressible, hyperelastic, transversely isotropic material using finite element (FE) methods. Bi-ventricular geometries of healthy rat hearts reconstructed from magnetic resonance images were imported in Abaqus©. In simulating the normal passive filling of the rat heart, pressures of 4.8 kPa and 0.0098 kPa were applied to the inner walls of the LV and RV respectively. In addition, to simulate the overpressure of the RV, pressures of 2.4 kPa and 4.8 kPa were applied to the endocardial walls of the LV and RV respectively. As boundary conditions, the circumferential and longitudinal displacements at the base were set to zero. The radial displacements at the base were left free. RESULTS The results show that the average circumferential stress at the mid-wall in the overloaded model increased from 2.8 kPa to 18.2 kPa. The average longitudinal stress increased from 1.5 kPa to 9.7 kPa. Additionally, in the radial direction, the average stress increased from 0.1 kPa to 0.6 kPa in the mid-wall. The average circumferential strain was found to be 0.138 and 0.100 on the endocardium of the over pressured and healthy model respectively. The average circumferential stress at the epicardium, mid-wall and endocardium in the case of a normal heart is 10 times lower than in the overloaded heart model. CONCLUSION The finite analysis method is able to provide insights into the behaviour of the over pressured model (myocardium). In the overloaded model the high stresses and strains were observed on the septal wall. The bi-ventricular model was shown to provide useful information relating to the over pressured ventricle. The possible heart dysfunction may be attributable to high stress and strain in the over pressured heart.
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Affiliation(s)
- Fulufhelo Masithulela
- Department of Mechanical and Industrial Engineering, College of Science and Engineering, University of South Africa, Pretoria, South Africa. E-mail: .,Chris Barnard Division of Cardiothoracic Surgery, University of Cape Town, Observatory, South Africa
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Wang Y, Cai W, Wang L, Xia R, Chen W, Zheng J, Gao F. Evaluation of the Differences of Myocardial Fibers between Acute and Chronic Myocardial Infarction: Application of Diffusion Tensor Magnetic Resonance Imaging in a Rhesus Monkey Model. Korean J Radiol 2016; 17:725-33. [PMID: 27587961 PMCID: PMC5007399 DOI: 10.3348/kjr.2016.17.5.725] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2015] [Accepted: 04/29/2016] [Indexed: 02/05/2023] Open
Abstract
Objective To understand microstructural changes after myocardial infarction (MI), we evaluated myocardial fibers of rhesus monkeys during acute or chronic MI, and identified the differences of myocardial fibers between acute and chronic MI. Materials and Methods Six fixed hearts of rhesus monkeys with left anterior descending coronary artery ligation for 1 hour or 84 days were scanned by diffusion tensor magnetic resonance imaging (MRI) to measure apparent diffusion coefficient (ADC), fractional anisotropy (FA) and helix angle (HA). Results Comparing with acute MI monkeys (FA: 0.59 ± 0.02; ADC: 5.0 ± 0.6 × 10-4 mm2/s; HA: 94.5 ± 4.4°), chronic MI monkeys showed remarkably decreased FA value (0.26 ± 0.03), increased ADC value (7.8 ± 0.8 × 10-4mm2/s), decreased HA transmural range (49.5 ± 4.6°) and serious defects on endocardium in infarcted regions. The HA in infarcted regions shifted to more components of negative left-handed helix in chronic MI monkeys (-38.3 ± 5.0°–11.2 ± 4.3°) than in acute MI monkeys (-41.4 ± 5.1°–53.1 ± 3.7°), but the HA in remote regions shifted to more components of positive right-handed helix in chronic MI monkeys (-43.8 ± 2.7°–66.5 ± 4.9°) than in acute MI monkeys (-59.5 ± 3.4°–64.9 ± 4.3°). Conclusion Diffusion tensor MRI method helps to quantify differences of mechanical microstructure and water diffusion of myocardial fibers between acute and chronic MI monkey's models.
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Affiliation(s)
- Yuqing Wang
- Department of Radiology, West China Hospital, Sichuan University, Sichuan 610041, China.; CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology of China, Beijing 100190, China
| | - Wei Cai
- Department of Radiology, West China Hospital, Sichuan University, Sichuan 610041, China.; Department of Radiology, Beijing Jishuitan Hospital, 4th Clinical Medical College of Peking University, Beijing 100035, China
| | - Lei Wang
- Department of Radiology, West China Hospital, Sichuan University, Sichuan 610041, China
| | - Rui Xia
- Department of Radiology, West China Hospital, Sichuan University, Sichuan 610041, China.; Department of Radiology, The First Affiliated Hospital, Chongqing Medical University, Chongqing 400016, China
| | - Wei Chen
- Department of Radiology, West China Hospital, Sichuan University, Sichuan 610041, China.; Department of Radiology, The First Affiliated Hospital of Kunming Medical University, Yunnan 650032, China
| | - Jie Zheng
- Mallinckrodt Institute of Radiology, School of Medicine, Washington University, St. Louis, MO 63110, USA
| | - Fabao Gao
- Department of Radiology, West China Hospital, Sichuan University, Sichuan 610041, China
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Wang Y, Cai W, Wang L, Xia R. Evaluate the early changes of myocardial fibers in rhesus monkey during sub-acute stage of myocardial infarction using diffusion tensor magnetic resonance imaging. Magn Reson Imaging 2015; 34:391-6. [PMID: 26708038 DOI: 10.1016/j.mri.2015.12.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 12/12/2015] [Indexed: 02/05/2023]
Abstract
PURPOSE The deterioration of cardiac mechanical function starts from the micro-alterations in the myocardial fibers after myocardial infarction (MI) due to the heart beats derived from the systole and diastole of the myocardial fibers. So, we want to evaluate quantitatively the early changes of myocardial fibers in rhesus monkey during sub-acute MI stage. MATERIALS AND METHODS Three fixed hearts with infarction after left anterior descending coronary artery ligation for 7days and eight age-matched intact controls were scanned by ex-vivo diffusion tensor magnetic resonance imaging (DT-MRI) to measure apparent diffusion coefficient (ADC), fractional anisotropy (FA) and helix angle (HA). RESULTS In comparison with healthy controls, FA and transmural range of HA in MI regions showed a significant reduction whereas ADC showed a significant increment (p<0.01). The double-helix myocardial fibers shifted further to left-handed helix around the infarcted and adjacent myocardium but shifted further to right-handed helix in remote myocardium. CONCLUSION HA is sensitive to evaluate quantitatively the early changes of myocardial fibers in sub-acute MI rhesus monkeys. The myocardial fibers in normal monkeys are similar to those in normal humans, suggesting that early changes of myocardial fibers in sub-acute MI monkeys can contribute to more accurately understand those in patients suffering sub-acute MI.
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Affiliation(s)
- Yuqing Wang
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology of China, No.11 ZhongGuanCun BeiYiTiao, Beijing, 100190, China.
| | - Wei Cai
- Department of Radiology, Beijing Jishuitan Hospital, 4th clinical medical college of Peking University, No.31 Xinjiekou East Road, Beijing, China, 100035
| | - Lei Wang
- Department of Radiology, West China Hospital, Sichuan University, No.37 Guoxue Alley, Chengdu, Sichuan, China, 610041
| | - Rui Xia
- Department of Radiology, The First Affiliated Hospital, Chongqing Medical University, No.1 Friendship Road, Chongqing, China, 400016
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David Gomez A, Bull DA, Hsu EW. Finite-Element Extrapolation of Myocardial Structure Alterations Across the Cardiac Cycle in Rats. J Biomech Eng 2015; 137:101010. [PMID: 26299478 DOI: 10.1115/1.4031419] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Indexed: 11/08/2022]
Abstract
Myocardial microstructures are responsible for key aspects of cardiac mechanical function. Natural myocardial deformation across the cardiac cycle induces measurable structural alteration, which varies across disease states. Diffusion tensor magnetic resonance imaging (DT-MRI) has become the tool of choice for myocardial structural analysis. Yet, obtaining the comprehensive structural information of the whole organ, in 3D and time, for subject-specific examination is fundamentally limited by scan time. Therefore, subject-specific finite-element (FE) analysis of a group of rat hearts was implemented for extrapolating a set of initial DT-MRI to the rest of the cardiac cycle. The effect of material symmetry (isotropy, transverse isotropy, and orthotropy), structural input, and warping approach was observed by comparing simulated predictions against in vivo MRI displacement measurements and DT-MRI of an isolated heart preparation at relaxed, inflated, and contracture states. Overall, the results indicate that, while ventricular volume and circumferential strain are largely independent of the simulation strategy, structural alteration predictions are generally improved with the sophistication of the material model, which also enhances torsion and radial strain predictions. Moreover, whereas subject-specific transversely isotropic models produced the most accurate descriptions of fiber structural alterations, the orthotropic models best captured changes in sheet structure. These findings underscore the need for subject-specific input data, including structure, to extrapolate DT-MRI measurements across the cardiac cycle.
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Bakermans AJ, Abdurrachim D, Moonen RPM, Motaal AG, Prompers JJ, Strijkers GJ, Vandoorne K, Nicolay K. Small animal cardiovascular MR imaging and spectroscopy. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2015; 88-89:1-47. [PMID: 26282195 DOI: 10.1016/j.pnmrs.2015.03.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 03/09/2015] [Accepted: 03/09/2015] [Indexed: 06/04/2023]
Abstract
The use of MR imaging and spectroscopy for studying cardiovascular disease processes in small animals has increased tremendously over the past decade. This is the result of the remarkable advances in MR technologies and the increased availability of genetically modified mice. MR techniques provide a window on the entire timeline of cardiovascular disease development, ranging from subtle early changes in myocardial metabolism that often mark disease onset to severe myocardial dysfunction associated with end-stage heart failure. MR imaging and spectroscopy techniques play an important role in basic cardiovascular research and in cardiovascular disease diagnosis and therapy follow-up. This is due to the broad range of functional, structural and metabolic parameters that can be quantified by MR under in vivo conditions non-invasively. This review describes the spectrum of MR techniques that are employed in small animal cardiovascular disease research and how the technological challenges resulting from the small dimensions of heart and blood vessels as well as high heart and respiratory rates, particularly in mice, are tackled.
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Affiliation(s)
- Adrianus J Bakermans
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Desiree Abdurrachim
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Rik P M Moonen
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Abdallah G Motaal
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Jeanine J Prompers
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Gustav J Strijkers
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Katrien Vandoorne
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Klaas Nicolay
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
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Jiang K, Yu X. Quantification of regional myocardial wall motion by cardiovascular magnetic resonance. Quant Imaging Med Surg 2014; 4:345-57. [PMID: 25392821 DOI: 10.3978/j.issn.2223-4292.2014.09.01] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2014] [Accepted: 09/12/2014] [Indexed: 12/12/2022]
Abstract
Cardiovascular magnetic resonance (CMR) is a versatile tool that also allows comprehensive and accurate measurement of both global and regional myocardial contraction. Quantification of regional wall motion parameters, such as strain, strain rate, twist and torsion, has been shown to be more sensitive to early-stage functional alterations. Since the invention of CMR tagging by magnetization saturation in 1988, several CMR techniques have been developed to enable the measurement of regional myocardial wall motion, including myocardial tissue tagging, phase contrast mapping, displacement encoding with stimulated echoes (DENSE), and strain encoded (SENC) imaging. These techniques have been developed with their own advantages and limitations. In this review, two widely used and closely related CMR techniques, i.e., tissue tagging and DENSE, will be discussed from the perspective of pulse sequence development and image-processing techniques. The clinical and preclinical applications of tissue tagging and DENSE in assessing wall motion mechanics in both normal and diseased hearts, including coronary artery diseases, hypertrophic cardiomyopathy, aortic stenosis, and Duchenne muscular dystrophies, will be discussed.
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Affiliation(s)
- Kai Jiang
- 1 Departments of Biomedical Engineering, 2 Case Center for Imaging Research, 3 Radiology, and 4 Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio, USA
| | - Xin Yu
- 1 Departments of Biomedical Engineering, 2 Case Center for Imaging Research, 3 Radiology, and 4 Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio, USA
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Yu Y, Zhang S, Li K, Metaxas D, Axel L. Deformable models with sparsity constraints for cardiac motion analysis. Med Image Anal 2014; 18:927-37. [PMID: 24721617 PMCID: PMC4876050 DOI: 10.1016/j.media.2014.03.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 03/08/2014] [Accepted: 03/11/2014] [Indexed: 11/18/2022]
Abstract
Deformable models integrate bottom-up information derived from image appearance cues and top-down priori knowledge of the shape. They have been widely used with success in medical image analysis. One limitation of traditional deformable models is that the information extracted from the image data may contain gross errors, which adversely affect the deformation accuracy. To alleviate this issue, we introduce a new family of deformable models that are inspired from the compressed sensing, a technique for accurate signal reconstruction by harnessing some sparseness priors. In this paper, we employ sparsity constraints to handle the outliers or gross errors, and integrate them seamlessly with deformable models. The proposed new formulation is applied to the analysis of cardiac motion using tagged magnetic resonance imaging (tMRI), where the automated tagging line tracking results are very noisy due to the poor image quality. Our new deformable models track the heart motion robustly, and the resulting strains are consistent with those calculated from manual labels.
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Affiliation(s)
- Yang Yu
- Department of Computer Science, Rutgers University, Piscataway, NJ, USA
| | - Shaoting Zhang
- Department of Computer Science, University of North Carolina at Charlotte, NC, USA.
| | - Kang Li
- Department of Industrial and Systems Engineering, Rutgers University, Piscataway, NJ, USA
| | - Dimitris Metaxas
- Department of Computer Science, Rutgers University, Piscataway, NJ, USA
| | - Leon Axel
- Radiology Department, New York University, New York, NY, USA
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Gomez AD, Merchant SS, Hsu EW. Accurate high-resolution measurements of 3-D tissue dynamics with registration-enhanced displacement encoded MRI. IEEE TRANSACTIONS ON MEDICAL IMAGING 2014; 33:1350-62. [PMID: 24771572 PMCID: PMC4163496 DOI: 10.1109/tmi.2014.2311755] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Displacement fields are important to analyze deformation, which is associated with functional and material tissue properties often used as indicators of health. Magnetic resonance imaging (MRI) techniques like DENSE and image registration methods like Hyperelastic Warping have been used to produce pixel-level deformation fields that are desirable in high-resolution analysis. However, DENSE can be complicated by challenges associated with image phase unwrapping, in particular offset determination. On the other hand, Hyperelastic Warping can be hampered by low local image contrast. The current work proposes a novel approach for measuring tissue displacement with both DENSE and Hyperelastic Warping, incorporating physically accurate displacements obtained by the latter to improve phase characterization in DENSE. The validity of the proposed technique is demonstrated using numerical and physical phantoms, and in vivo small animal cardiac MRI.
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Affiliation(s)
- Arnold D. Gomez
- Bioengineering Department, University of Utah, Salt Lake City, UT 84102 USA, and also with the Cardiothoracic Surgery Division, School of Medicine, University of Utah, UT 84102 USA
| | - Samer S. Merchant
- Bioengineering Department at the University of Utah, Salt Lake City, UT 84102 USA
| | - Edward W. Hsu
- Bioengineering Department at the University of Utah, Salt Lake City, UT 84102 USA
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Zhang H, Wei Z, Zhu X, Li H, Yu M, Duan Y, Zhu T, Zhang J, Zhou X, Zhu M. Assessment of left ventricular myocardial systolic acceleration in diabetic rats using velocity vector imaging. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2014; 33:875-883. [PMID: 24764343 DOI: 10.7863/ultra.33.5.875] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
OBJECTIVES The purpose of this study was to investigate how the myocardial acceleration during isovolumic contraction changed in rats with diabetic cardiomyopathy and a normal left ventricular ejection fraction (LVEF) by using velocity vector imaging. METHODS Velocity vector imaging was performed in 12 control rats and 15 rats with streptozotocin-induced diabetic cardiomyopathy 12 weeks after streptozotocin injection. The segmental radial displacement, velocity, acceleration, and percent wall thickening were measured at the mid-left ventricular (LV) level. RESULTS Compared to control rats, rats with cardiomyopathy had a significant decrease in the peak radial acceleration during isovolumic contraction in most segments of the LV wall (including the anterior, anterolateral, inferolateral, and inferior segments; P < .05) but a similar LVEF, fractional shortening, and segmental displacement. Rats with cardiomyopathy also had a significant increase in LV end-diastolic and end-systolic diameters when corrected for body mass (P < .001; P = .003, respectively) and a significant decrease in the radial peak systolic velocities of the inferolateral and inferior wall segments (P < .05). In addition, rats with cardiomyopathy had a significant decrease in the peak radial diastolic acceleration in most segments of the LV wall (except for the anterolateral one; P< .05) but similar peak radial diastolic velocities in all LV wall segments compared to controls. Pathologic examination in rats with cardiomyopathy revealed ultrastructural impairment of the capillary and cardiocyte without any atherosclerotic lesion in the coronary artery compared to control rats. CONCLUSIONS Myocardial acceleration during isovolumic contraction decreases in rats with diabetic cardiomyopathy and a preserved LVEF, suggesting the presence of regional LV systolic dysfunction.
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Affiliation(s)
- Haibin Zhang
- Department of Ultrasound, PLA 210th Hospital, 116011 Dalian, Liaoning, China.
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Chen Y, Ye L, Zhong J, Li X, Yan C, Chandler MP, Calvin S, Xiao F, Negia M, Low WC, Zhang J, Yu X. The Structural Basis of Functional Improvement in Response to Human Umbilical Cord Blood Stem Cell Transplantation in Hearts With Postinfarct LV Remodeling. Cell Transplant 2013; 24:971-83. [PMID: 24332083 DOI: 10.3727/096368913x675746] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Cellular therapy for myocardial repair has been one of the most intensely investigated interventional strategies for acute myocardial infarction. Although the therapeutic potential of stem cells has been demonstrated in various studies, the underlying mechanisms for such improvements are poorly understood. In the present study, we investigated the long-term effects of stem cell therapy on both myocardial fiber organization and regional contractile function using a rat model of postinfarct remodeling. Human nonhematopoietic umbilical cord blood stem cells (nh-UCBSCs) were administered via tail vein to rats 2 days after infarct surgery. Animals were maintained without immunosuppressive therapy. In vivo and ex vivo MR imaging was performed on infarct hearts 10 months after cell transplantation. Compared to the age-matched rats exposed to the identical surgery, both global and regional cardiac functions of the nh-UCBSC-treated hearts, such as ejection fraction, ventricular strain, and torsion, were significantly improved. More importantly, the treated hearts exhibited preserved fiber orientation and water diffusivities that were similar to those in sham-operated control hearts. These data provide the first evidence that nh-UCBSC treatment may prevent/delay untoward structural remodeling in postinfarct hearts, which supports the improved LV function observed in vivo in the absence of immunosuppression, suggesting a beneficial paracrine effect occurred with the cellular therapy.
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Affiliation(s)
- Yong Chen
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
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Moyer CB, Helm PA, Clarke CJ, Budge LP, Kramer CM, Ferguson JD, Norton PT, Holmes JW. Wall-motion based analysis of global and regional left atrial mechanics. IEEE TRANSACTIONS ON MEDICAL IMAGING 2013; 32:1765-1776. [PMID: 23708788 PMCID: PMC4427253 DOI: 10.1109/tmi.2013.2264062] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Atrial fibrillation is an increasingly prevalent cardiovascular disease; changes in atrial structure and function induced by atrial fibrillation and its treatments are often spatially heterogeneous. However, spatial heterogeneity of function is difficult to assess with standard imaging techniques. This paper describes a method to assess global and regional mechanical function by combining cardiac magnetic resonance imaging and finite-element surface fitting. We used this fitted surface to derive measures of left atrial volume, regional motion, and spatial heterogeneity of motion in 23 subjects, including healthy volunteers and atrial fibrillation patients. We fit the surfaces using a Newton optimization scheme in under 1 min on a standard laptop, with a root mean square error of 2.3 ± 0.5 mm, less than 9% of the mean fitted radius, and an inter-operator variability of less than 10%. Fitted surfaces showed clear definition of the phases of left atrial motion (filling, passive emptying, active contraction) in both volume-time and regional radius-time curves. Averaged surfaces of healthy volunteers and atrial fibrillation patients provided evidence of substantial regional variation in both amount and timing of regional motion, indicating spatial heterogeneity of function, even in healthy adults.
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Espe EKS, Aronsen JM, Skårdal K, Schneider JE, Zhang L, Sjaastad I. Novel insight into the detailed myocardial motion and deformation of the rodent heart using high-resolution phase contrast cardiovascular magnetic resonance. J Cardiovasc Magn Reson 2013; 15:82. [PMID: 24034168 PMCID: PMC3848852 DOI: 10.1186/1532-429x-15-82] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 09/03/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Phase contrast velocimetry cardiovascular magnetic resonance (PC-CMR) is a powerful and versatile tool allowing assessment of in vivo motion of the myocardium. However, PC-CMR is sensitive to motion related artifacts causing errors that are geometrically systematic, rendering regional analysis of myocardial function challenging. The objective of this study was to establish an optimized PC-CMR method able to provide novel insight in the complex regional motion and strain of the rodent myocardium, and provide a proof-of-concept in normal and diseased rat hearts with higher temporal and spatial resolution than previously reported. METHODS A PC-CMR protocol optimized for assessing the motion and deformation of the myocardium in rats with high spatiotemporal resolution was established, and ten animals with different degree of cardiac dysfunction underwent examination and served as proof-of-concept. Global and regional myocardial velocities and circumferential strain were calculated, and the results were compared to five control animals. Furthermore, the global strain measurements were validated against speckle-tracking echocardiography, and inter- and intrastudy variability of the protocol were evaluated. RESULTS The presented method allows assessment of regional myocardial function in rats with high level of detail; temporal resolution was 3.2 ms, and analysis was done using 32 circumferential segments. In the dysfunctional hearts, global and regional function were distinctly altered, including reduced global peak values, increased regional heterogeneity and increased index of dyssynchrony. Strain derived from the PC-CMR data was in excellent agreement with echocardiography (r = 0.95, p < 0.001; limits-of-agreement -0.02 ± 3.92%strain), and intra- and interstudy variability were low for both velocity and strain (limits-of-agreement, radial motion: 0.01 ± 0.32 cm/s and -0.06 ± 0.75 cm/s; circumferential strain: -0.16 ± 0.89%strain and -0.71 ± 1.67%strain, for intra- and interstudy, respectively). CONCLUSION We demonstrate, for the first time, that PC-CMR enables high-resolution evaluation of in vivo circumferential strain in addition to myocardial motion of the rat heart. In combination with the superior geometric robustness of CMR, this ultimately provides a tool for longitudinal studies of regional function in rodents with high level of detail.
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Affiliation(s)
- Emil KS Espe
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Kirkeveien 166, N-0407, Oslo, Norway
- KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Jan Magnus Aronsen
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Kirkeveien 166, N-0407, Oslo, Norway
- KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway
- Bjørknes College, Oslo, Norway
| | - Kristine Skårdal
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Kirkeveien 166, N-0407, Oslo, Norway
- KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | | | - Lili Zhang
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Kirkeveien 166, N-0407, Oslo, Norway
- KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Ivar Sjaastad
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Kirkeveien 166, N-0407, Oslo, Norway
- KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway
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Akki A, Gupta A, Weiss RG. Magnetic resonance imaging and spectroscopy of the murine cardiovascular system. Am J Physiol Heart Circ Physiol 2013; 304:H633-48. [PMID: 23292717 DOI: 10.1152/ajpheart.00771.2011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Magnetic resonance imaging (MRI) has emerged as a powerful and reliable tool to noninvasively study the cardiovascular system in clinical practice. Because transgenic mouse models have assumed a critical role in cardiovascular research, technological advances in MRI have been extended to mice over the last decade. These have provided critical insights into cardiac and vascular morphology, function, and physiology/pathophysiology in many murine models of heart disease. Furthermore, magnetic resonance spectroscopy (MRS) has allowed the nondestructive study of myocardial metabolism in both isolated hearts and in intact mice. This article reviews the current techniques and important pathophysiological insights from the application of MRI/MRS technology to murine models of cardiovascular disease.
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Affiliation(s)
- Ashwin Akki
- Division of Cardiology, Department of Medicine, and Division of Magnetic Resonance Research, Department of Radiology, The Johns Hopkins University, School of Medicine, Baltimore, MD, USA
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Jung B, Odening KE, Dall’Armellina E, Föll D, Menza M, Markl M, Schneider JE. A quantitative comparison of regional myocardial motion in mice, rabbits and humans using in-vivo phase contrast CMR. J Cardiovasc Magn Reson 2012; 14:87. [PMID: 23270566 PMCID: PMC3579745 DOI: 10.1186/1532-429x-14-87] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Accepted: 12/06/2012] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Genetically manipulated animals like mice or rabbits play an important role in the exploration of human cardiovascular diseases. It is therefore important to identify animal models that closely mimic physiological and pathological human cardiac function. METHODS In-vivo phase contrast cardiovascular magnetic resonance (CMR) was used to measure regional three-directional left ventricular myocardial motion with high temporal resolution in mice (N=18), rabbits (N=8), and humans (N=20). Radial, long-axis, and rotational myocardial velocities were acquired in left ventricular basal, mid-ventricular, and apical short-axis locations. RESULTS Regional analysis revealed different patterns of motion: 1) In humans and rabbits, the apex showed slower radial velocities compared to the base. 2) Significant differences within species were seen in the pattern of long-axis motion. Long-axis velocities during systole were fairly homogeneously distributed in mice, whereas humans showed a dominant component in the lateral wall and rabbits in the base. 3) Rotational velocities and twist showed the most distinct patterns in both temporal evolution and relative contribution of base, mid-ventricle and apex, respectively. Interestingly, a marked difference in rotational behavior during early-systole was found in mice, which exhibited clockwise rotation in all slice locations compared to counter-clockwise rotation in rabbits and humans. CONCLUSIONS Phase contrast CMR revealed subtle, but significantly different regional myocardial motion patterns in mice, rabbits and humans. This finding has to be considered when investigating myocardial motion pattern in small animal models of heart disease.
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Affiliation(s)
- Bernd Jung
- Department of Radiology, Medical Physics, University Medical Center, Freiburg, Germany
| | - Katja E Odening
- Department of Cardiology, University Medical Center, Freiburg, Germany
| | | | - Daniela Föll
- Department of Cardiology, University Medical Center, Freiburg, Germany
| | - Marius Menza
- Department of Radiology, Medical Physics, University Medical Center, Freiburg, Germany
| | - Michael Markl
- Department of Radiology, Northwestern University, Chicago, IL, USA
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Azam S, Desjardins CL, Schluchter M, Liner A, Stelzer JE, Yu X, Hoit BD. Comparison of velocity vector imaging echocardiography with magnetic resonance imaging in mouse models of cardiomyopathy. Circ Cardiovasc Imaging 2012; 5:776-81. [PMID: 22977126 DOI: 10.1161/circimaging.111.972406] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Myocardial strain imaging using echocardiography can be a cost-effective method to quantify ventricular wall motion objectively, but few studies have compared strain measured with echocardiography against magnetic resonance imaging (MRI) in small animals. METHODS AND RESULTS We compared circumferential strain (CS) and radial strain (RS) measured with echocardiography (velocity vector imaging [VVI]) to displacement encoding with stimulated-echo MRI in 2 mouse models of cardiomyopathy. In 3-month-old mice with gene targeted deficiency of cardiac myosin-binding protein-C (cMyBP-C(-/-), n=6) or muscle LIM protein (MLP(-/-), n=6), and wild-type mice (n=8), myocardial strains were measured at 3 cross-sectional levels and averaged to obtain global strains. There was modest correlation between VVI and MRI measured strains, with global CS yielding stronger correlation compared with global RS (CS R(2)=0.4452 versus RS R(2)=0.2794, both P<0.05). Overall, strain measured by VVI was more variable than MRI (P<0.05) and the limits of agreement were slightly, but not significantly (P=0.14), closer for global CS than RS. Both VVI and MRI strain measurements showed significantly lower global CS strain in the knockout groups compared with the wild type. The VVI (but not MRI) CS strain measurements were different between the 2 knockout groups (-14.5±3.8% versus -6.6±4.0%, cMyBP-C(-/-) versus MLP(-/-) respectively, P<0.05). CONCLUSIONS Measurements of left ventricular CS and RS are feasible in small animals using 2-dimensional echocardiography. VVI and MRI strain measurements correlated modestly and the agreement between the modalities tended to be greater for CS than RS. Although VVI and MRI strains were able to differentiate between wild-type and knockout mice, only global CS VVI differentiated between the 2 models of cardiomyopathy.
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Affiliation(s)
- Salman Azam
- Harrington Heart and Vascular Institute, University Hospitals Case Medical Center, Case Western Reserve University, Cleveland, OH 44106-5038, USA
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How similar are the mice to men? Between-species comparison of left ventricular mechanics using strain imaging. PLoS One 2012; 7:e40061. [PMID: 22768220 PMCID: PMC3386935 DOI: 10.1371/journal.pone.0040061] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Accepted: 05/31/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND While mammalian heart size maintains constant proportion to whole body size, scaling of left ventricular (LV) function parameters shows a more complex scaling pattern. We used 2-D speckle tracking strain imaging to determine whether LV myocardial strains and strain rates scale to heart size. METHODS We studied 18 mice, 15 rats, 6 rabbits, 12 dogs and 20 human volunteers by 2-D echocardiography. Relationship between longitudinal or circumferential strains/strain rates (S(Long)/SR(Long), S(Circ)/SR(Circ)), and LV end-diastolic volume (EDV) or mass were assessed by the allometric (power-law) equation Y = kM(β). RESULTS Mean LV mass in individual species varied from 0.038 to 134 g, LV EDV varied from 0.015 to 102 ml, while RR interval varied from 81 to 1090 ms. While S(Long) increased with increasing LV EDV or mass (β values 0.047±0.006 and 0.051±0.005, p<0.0001 vs. 0 for both) S(Circ) was unchanged (p = NS for both LV EDV or mass). Systolic and diastolic SR(Long) and SR(Circ) showed inverse correlations to LV EDV or mass (p<0.0001 vs. 0 for all comparisons). The ratio between S(Long) and S(Circ) increased with increasing values of LV EDV or mass (β values 0.039±0.010 and 0.040±0.011, p>0.0003 for both). CONCLUSIONS While S(Circ) is unchanged, S(Long) increases with increasing heart size, indicating that large mammals rely more on long axis contribution to systolic function. SR(Long) and SR(Circ), both diastolic and systolic, show an expected decrease with increasing heart size.
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Abstract
A heart attack kills off many cells in the heart. Parts of the heart become thin and fail to contract properly following the replacement of lost cells by scar tissue. However, the notion that the same adult cardiomyocytes beat throughout the lifespan of the organ and organism, without the need for a minimum turnover, gives way to a fascinating investigations. Since the late 1800s, scientists and cardiologists wanted to demonstrate that the cardiomyocytes cannot be generated after the perinatal period in human beings. This curiosity has been passed down in subsequent years and has motivated more and more accurate studies in an attempt to exclude the presence of renewed cardiomyocytes in the tissue bordering the ischaemic area, and then to confirm the dogma of the heart as terminally differentiated organ. Conversely, peri-lesional mitosis of cardiomyocytes were discovered initially by light microscopy and subsequently confirmed by more sophisticated technologies. Controversial evidence of mechanisms underlying myocardial regeneration has shown that adult cardiomyocytes are renewed through a slow turnover, even in the absence of damage. This turnover is ensured by the activation of rare clusters of progenitor cells interspersed among the cardiac cells functionally mature. Cardiac progenitor cells continuously interact with each other, with the cells circulating in the vessels of the coronary microcirculation and myocardial cells in auto-/paracrine manner. Much remains to be understood; however, the limited functional recovery in human beings after myocardial injury clearly demonstrates weak regenerative potential of cardiomyocytes and encourages the development of new approaches to stimulate this process.
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Affiliation(s)
- Lucio Barile
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
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Rane AA, Christman KL. Biomaterials for the treatment of myocardial infarction: a 5-year update. J Am Coll Cardiol 2012; 58:2615-29. [PMID: 22152947 DOI: 10.1016/j.jacc.2011.11.001] [Citation(s) in RCA: 185] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 10/28/2011] [Accepted: 11/01/2011] [Indexed: 01/21/2023]
Abstract
The first review on biomaterials for the treatment of myocardial infarction (MI) was written in 2006. In the last 5 years, the general approaches for biomaterial treatment of MI and subsequent left ventricular remodeling remain the same, namely, left ventricular restraints, epicardial patches, and injectable therapies. Nonetheless, there have been significant developments in this field, including advancement of biomaterial therapies to large animal pre-clinical studies and, more recently, to clinical trials. This review focuses on the progress made in the field of cardiac biomaterial treatments for MI over the last 5 years.
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Affiliation(s)
- Aboli A Rane
- Department of Bioengineering, University of California-San Diego, La Jolla, USA
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31
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Nagao M, Hatakenaka M, Matsuo Y, Kamitani T, Higuchi K, Shikata F, Nagashima M, Mochizuki T, Honda H. Subendocardial contractile impairment in chronic ischemic myocardium: assessment by strain analysis of 3T tagged CMR. J Cardiovasc Magn Reson 2012; 14:14. [PMID: 22300290 PMCID: PMC3286365 DOI: 10.1186/1532-429x-14-14] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Accepted: 02/02/2012] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND The purpose of this study was to quantify myocardial strain on the subendocardial and epicardial layers of the left ventricle (LV) using tagged cardiovascular magnetic resonance (CMR) and to investigate the transmural degree of contractile impairment in the chronic ischemic myocardium. METHODS 3T tagged CMR was performed at rest in 12 patients with severe coronary artery disease who had been scheduled for coronary artery bypass grafting. Circumferential strain (C-strain) at end-systole on subendocardial and epicardial layers was measured using the short-axis tagged images of the LV and available software (Intag; Osirix). The myocardial segment was divided into stenotic and non-stenotic segments by invasive coronary angiography, and ischemic and non-ischemic segments by stress myocardial perfusion scintigraphy. The difference in C-strain between the two groups was analyzed using the Mann-Whitney U-test. The diagnostic capability of C-strain was analyzed using receiver operating characteristics analysis. RESULTS The absolute subendocardial C-strain was significantly lower for stenotic (-7.5 ± 12.6%) than non-stenotic segment (-18.8 ± 10.2%, p < 0.0001). There was no difference in epicardial C-strain between the two groups. Use of cutoff thresholds for subendocardial C-strain differentiated stenotic segments from non-stenotic segments with a sensitivity of 77%, a specificity of 70%, and areas under the curve (AUC) of 0.76. The absolute subendocardial C-strain was significantly lower for ischemic (-6.7 ± 13.1%) than non-ischemic segments (-21.6 ± 7.0%, p < 0.0001). The absolute epicardial C-strain was also significantly lower for ischemic (-5.1 ± 7.8%) than non-ischemic segments (-9.6 ± 9.1%, p < 0.05). Use of cutoff thresholds for subendocardial C-strain differentiated ischemic segments from non-ischemic segments with sensitivities of 86%, specificities of 84%, and AUC of 0.86. CONCLUSIONS Analysis of tagged CMR can non-invasively demonstrate predominant impairment of subendocardial strain in the chronic ischemic myocardium at rest.
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Affiliation(s)
- Michinobu Nagao
- Department of Molecular Imaging and Diagnosis, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka, 812-8582, Japan
| | - Masamitsu Hatakenaka
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka, 812-8582, Japan
| | - Yoshio Matsuo
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka, 812-8582, Japan
| | - Takeshi Kamitani
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka, 812-8582, Japan
| | - Ko Higuchi
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka, 812-8582, Japan
| | - Fumiaki Shikata
- Department of Cardiovascular Surgery, Ehime University Graduate School of Medicine, Shitsukawa, Toon-city, Ehime, 791-0295, Japan
| | - Mitsugi Nagashima
- Department of Cardiovascular Surgery, Ehime University Graduate School of Medicine, Shitsukawa, Toon-city, Ehime, 791-0295, Japan
| | - Teruhito Mochizuki
- Department of Radiology, Ehime University Graduate School of Medicine, Shitsukawa, Toon-city, Ehime, 791-0295, Japan
| | - Hiroshi Honda
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka, 812-8582, Japan
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Abstract
High-resolution magnetic resonance cine imaging (cine-MRI) allows for a non-invasive assessment of ventricular function and mass in normal mice and in genetically and surgically modified mouse models of cardiac disease. The assessment of myocardial mass and function by cine-MRI does not rely on geometric assumptions, as the hearts are covered from the base to the apex, typically by a stack of two-dimensional images. The MR data acquisition is then followed by image segmentation of specific cine frames in each slice to obtain geometric and functional parameters, such as end-diastolic volume (EDV), end-systolic volume (ESV) or ejection fraction (EF). This technique has been well established in clinical routine application and it is now also becoming the reference method in experimental cardiovascular MRI. The cine images are typically acquired in short- and long-axis orientations of the heart to facilitate an accurate assessment of cardiac functional parameters. These views can be difficult to identify, particularly in animals with diseased hearts. Furthermore, data analysis can be the source of a systematic error, mainly for myocardial mass measurement. We have established protocols that allow for a quick and reproducible way of obtaining the relevant cardiac views for cine-MRI, and for accurate image analysis.
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Zhong X, Gibberman LB, Spottiswoode BS, Gilliam AD, Meyer CH, French BA, Epstein FH. Comprehensive cardiovascular magnetic resonance of myocardial mechanics in mice using three-dimensional cine DENSE. J Cardiovasc Magn Reson 2011; 13:83. [PMID: 22208954 PMCID: PMC3278394 DOI: 10.1186/1532-429x-13-83] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Accepted: 12/30/2011] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Quantitative noninvasive imaging of myocardial mechanics in mice enables studies of the roles of individual genes in cardiac function. We sought to develop comprehensive three-dimensional methods for imaging myocardial mechanics in mice. METHODS A 3D cine DENSE pulse sequence was implemented on a 7T small-bore scanner. The sequence used three-point phase cycling for artifact suppression and a stack-of-spirals k-space trajectory for efficient data acquisition. A semi-automatic 2D method was adapted for 3D image segmentation, and automated 3D methods to calculate strain, twist, and torsion were employed. A scan protocol that covered the majority of the left ventricle in a scan time of less than 25 minutes was developed, and seven healthy C57Bl/6 mice were studied. RESULTS Using these methods, multiphase normal and shear strains were measured, as were myocardial twist and torsion. Peak end-systolic values for the normal strains at the mid-ventricular level were 0.29 ± 0.17, -0.13 ± 0.03, and -0.18 ± 0.14 for E(rr), E(cc), and E(ll), respectively. Peak end-systolic values for the shear strains were 0.00 ± 0.08, 0.04 ± 0.12, and 0.03 ± 0.07 for E(rc), E(rl), and E(cl), respectively. The peak end-systolic normalized torsion was 5.6 ± 0.9°. CONCLUSIONS Using a 3D cine DENSE sequence tailored for cardiac imaging in mice at 7 T, a comprehensive assessment of 3D myocardial mechanics can be achieved with a scan time of less than 25 minutes and an image analysis time of approximately 1 hour.
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Affiliation(s)
| | | | - Bruce S Spottiswoode
- MRC/UCT Medical Imaging Research Unit, University of Cape Town, Cape Town, South Africa
| | | | - Craig H Meyer
- Radiology Department, University of Virginia, Charlottesville, USA
- Biomedical Engineering Department, University of Virginia, Charlottesville, USA
| | - Brent A French
- Biomedical Engineering Department, University of Virginia, Charlottesville, USA
| | - Frederick H Epstein
- Radiology Department, University of Virginia, Charlottesville, USA
- Biomedical Engineering Department, University of Virginia, Charlottesville, USA
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Desjardins CL, Chen Y, Coulton AT, Hoit BD, Yu X, Stelzer JE. Cardiac myosin binding protein C insufficiency leads to early onset of mechanical dysfunction. Circ Cardiovasc Imaging 2011; 5:127-36. [PMID: 22157650 DOI: 10.1161/circimaging.111.965772] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Decreased expression of cardiac myosin binding protein C (cMyBPC) as a result of genetic mutations may contribute to the development of hypertrophic cardiomyopathy (HCM); however, the mechanisms that link cMyBPC expression and HCM development, especially contractile dysfunction, remain unclear. METHODS AND RESULTS We evaluated cardiac mechanical function in vitro and in vivo in young mice (8-10 weeks of age) carrying no functional cMyBPC alleles (cMyBPC(-/-)) or 1 functional cMyBPC allele (cMyBPC(±)). Skinned myocardium isolated from cMyBPC(-/-) hearts displayed significant accelerations in stretch activation cross-bridge kinetics. Cardiac MRI studies revealed severely depressed in vivo left ventricular (LV) magnitude and rates of LV wall strain and torsion compared with wild-type (WT) mice. Heterozygous cMyBPC(±) hearts expressed 23±5% less cMyBPC than WT hearts but did not display overt hypertrophy. Skinned myocardium isolated from cMyBPC(±) hearts displayed small accelerations in the rate of stretch induced cross-bridge recruitment. MRI measurements revealed reductions in LV torsion and circumferential strain, as well reduced circumferential strain rates in early systole and diastole. CONCLUSIONS Modest decreases in cMyBPC expression in the mouse heart result in early-onset subtle changes in cross-bridge kinetics and in vivo LV mechanical function, which could contribute to the development of HCM later in life.
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Affiliation(s)
- Candida L Desjardins
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH 44106, USA
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Healy LJ, Jiang Y, Hsu EW. Quantitative comparison of myocardial fiber structure between mice, rabbit, and sheep using diffusion tensor cardiovascular magnetic resonance. J Cardiovasc Magn Reson 2011; 13:74. [PMID: 22117695 PMCID: PMC3235060 DOI: 10.1186/1532-429x-13-74] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Accepted: 11/25/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Accurate interpretations of cardiac functions require precise structural models of the myocardium, but the latter is not available always and for all species. Although scaling or substitution of myocardial fiber information from alternate species has been used in cardiac functional modeling, the validity of such practice has not been tested. METHODS Fixed mouse (n = 10), rabbit (n = 6), and sheep (n = 5) hearts underwent diffusion tensor imaging (DTI). The myocardial structures in terms of the left ventricular fiber orientation helix angle index were quantitatively compared between the mouse rabbit and sheep hearts. RESULTS The results show that significant fiber structural differences exist between any two of the three species. Specifically, the subepicardial fiber orientation, and the transmural range and linearity of fiber helix angles are significantly different between the mouse and either rabbit or sheep. Additionally, a significant difference was found between the transmural helix angle range between the rabbit and sheep. Across different circumferential regions of the heart, the fiber orientation was not found to be significantly different. CONCLUSIONS The current study indicates that myocardial structural differences exist between different size hearts. An immediate implication of the present findings for myocardial structural or functional modeling studies is that caution must be exercised when extrapolating myocardial structures from one species to another.
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Affiliation(s)
- Lindsey J Healy
- Department of Bioengineering, University of Utah, Salt Lake City, Utah, USA
| | - Yi Jiang
- Center for In Vivo Microscopy, Duke University Medical Center, Durham, North Carolina, USA
| | - Edward W Hsu
- Department of Bioengineering, University of Utah, Salt Lake City, Utah, USA
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Ertracht O, Liani E, Bachner-Hinenzon N, Bar-Am O, Frolov L, Ovcharenko E, Awad H, Blum S, Barac Y, Amit T, Adam D, Youdim M, Binah O. The cardioprotective efficacy of TVP1022 in a rat model of ischaemia/reperfusion. Br J Pharmacol 2011; 163:755-69. [PMID: 21323905 DOI: 10.1111/j.1476-5381.2011.01274.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND AND PURPOSE Because myocardial infarction is a major cause of morbidity and mortality worldwide, protecting the heart from the ischaemia and reperfusion (I/R) damage is the focus of intense research. Based on our in vitro findings showing that TVP1022 (the S-enantiomer of rasagiline, an anti-Parkinsonian drug) possesses cardioprotective effects, in the present study we investigated the hypothesis that TVP1022 can attenuate myocardial damage in an I/R model in rats. EXPERIMENTAL APPROACH The model consisted of 30-min occlusion of the left anterior descending artery followed by 4 or 24 h reperfusion. In addition, we investigated the possible mechanisms of cardioprotection in H9c2 cells and neonatal rat ventricular myocytes (NRVM) exposed to oxidative stress induced by H(2) O(2) . KEY RESULTS TVP1022 (20 and 40 mg·kg(-1) ) administered 5 min before reperfusion followed by an additional dose 4 h after reperfusion reduced the infarct size and attenuated the decline in ventricular function. TVP1022 also attenuated I/R-induced deterioration in cardiac mitochondrial integrity evaluated by mitochondrial swelling capacity. In vitro, using H9c2 cells and NRVM, TVP1022 attenuated both serum free- and H(2) O(2) -induced damage, preserved mitochondrial membrane potential and Bcl-2 levels, inhibited mitochondrial cytochrome c release and the increase in cleaved caspase 9 and 3 levels, and enhanced the phosphorylation of protein kinase C and glycogen synthase kinase-3β. CONCLUSIONS AND IMPLICATIONS TVP1022 provided cardioprotection in a model of myocardial infarction, and therefore should be considered as a novel adjunctive therapy for attenuating myocardial damage resulting from I/R injuries.
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Affiliation(s)
- Offir Ertracht
- Department of Physiology, Technion-Israel Institute of Technology, Haifa, Israel
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Gandolfi F, Vanelli A, Pennarossa G, Rahaman M, Acocella F, Brevini TAL. Large animal models for cardiac stem cell therapies. Theriogenology 2011; 75:1416-25. [PMID: 21463721 DOI: 10.1016/j.theriogenology.2011.01.026] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Revised: 01/18/2011] [Accepted: 01/23/2011] [Indexed: 01/12/2023]
Abstract
Cardiovascular disease is the leading cause of death in developed countries and is one of the leading causes of disease burden in developing countries. Therapies have markedly increased survival in several categories of patients, nonetheless mortality still remains high. For this reason high hopes are associated with recent developments in stem cell biology and regenerative medicine that promise to replace damaged or lost cardiac muscle with healthy tissue, and thus to dramatically improve the quality of life and survival in patients with various cardiomyopathies. Much of our insight into the molecular and cellular basis of cardiovascular biology comes from small animal models, particularly mice. However, significant differences exist with regard to several cardiac characteristics when mice are compared with humans. For this reason, large animal models like dog, sheep and pig have a well established role in cardiac research. A distinct characteristic of cardiac stem cells is that they can either be endogenous or derive from outside the heart itself; they can originate as the natural course of their differentiation programme (e.g., embryonic stem cells) or can be the result of specific inductive conditions (e.g., mesenchymal stem cells). In this review we will summarize the current knowledge on the kind of heart-related stem cells currently available in large animal species and their relevance to human studies as pre-clinical models.
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Affiliation(s)
- F Gandolfi
- Centre for Stem Cell Research, Università degli Studi di Milano, Milano, Italy.
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Vandsburger MH, Epstein FH. Emerging MRI methods in translational cardiovascular research. J Cardiovasc Transl Res 2011; 4:477-92. [PMID: 21452060 DOI: 10.1007/s12265-011-9275-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Accepted: 03/15/2011] [Indexed: 12/11/2022]
Abstract
Cardiac magnetic resonance imaging (CMR) has become a reference standard modality for imaging of left ventricular (LV) structure and function and, using late gadolinium enhancement, for imaging myocardial infarction. Emerging CMR techniques enable a more comprehensive examination of the heart, making CMR an excellent tool for use in translational cardiovascular research. Specifically, emerging CMR methods have been developed to measure the extent of myocardial edema, changes in ventricular mechanics, changes in tissue composition as a result of fibrosis, and changes in myocardial perfusion as a function of both disease and infarct healing. New CMR techniques also enable the tracking of labeled cells, molecular imaging of biomarkers of disease, and changes in calcium flux in cardiomyocytes. In addition, MRI can quantify blood flow velocity and wall shear stress in large blood vessels. Almost all of these techniques can be applied in both pre-clinical and clinical settings, enabling both the techniques themselves and the knowledge gained using such techniques in pre-clinical research to be translated from the lab bench to the patient bedside.
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Affiliation(s)
- Moriel H Vandsburger
- Department of Biological Regulation, Weizmann Institute of Science, 76100, Rehovot, Israel.
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Chuang JS, Zemljic-Harpf A, Ross RS, Frank LR, McCulloch AD, Omens JH. Determination of three-dimensional ventricular strain distributions in gene-targeted mice using tagged MRI. Magn Reson Med 2011; 64:1281-8. [PMID: 20981782 DOI: 10.1002/mrm.22547] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A model-based method for calculating three-dimensional (3D) cardiac wall strain distributions in the mouse has been developed and tested in a genetically engineered mouse model of dilated cardiomyopathy. Data from MR tagging and harmonic phase (HARP) tracking were used to measure material point displacements, and 3D Lagrangian strains were calculated throughout the entire left ventricle (LV) with a deformable parametric model. A mouse model where cardiomyocytes are specifically made deficient in vinculin (VclKO) were compared to wild-type (WT) littermates. 3D strain analysis revealed differences in LV wall mechanics between WT and VclKO mice at 8 weeks of age when systolic function had just begun to decline. Most notably, end-systolic radial strain and torsional shear were reduced in VclKO hearts which contributed to regional mechanical dysfunction. This study demonstrates the feasibility of using MRI tagging methods to detect alterations in 3D myocardial strain distributions in genetically engineered mouse models of cardiovascular disease.
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Affiliation(s)
- Joyce S Chuang
- Department of Bioengineering, University of California-San Diego, La Jolla, California, USA
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Li W, Yu X. Quantification of myocardial strain at early systole in mouse heart: restoration of undeformed tagging grid with single-point HARP. J Magn Reson Imaging 2011; 32:608-14. [PMID: 20815058 DOI: 10.1002/jmri.22256] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To develop accurate strain and torsion quantification method for the assessment of myocardial contraction in mice by MRI tagging. MATERIALS AND METHODS Ventricular wall motion at baseline and during beta-adrenergic stimulation was assessed in mice using MRI tagging. Myocardial strain and torsion were quantified using finite element analysis method. A harmonic phase (HARP) based method was developed for the restoration of undeformed taglines for more accurate calculation of myocardial wall strain and torsion. RESULTS Myocardial deformation was observed at early systole (<20 msec after QRS) both at baseline and during beta-adrenergic stimulation. The HARP-based method allowed robust restoration of undeformed taglines that can be used as the reference in finite element analysis of the tagged images. Without such correction for myocardial deformation in the reference image, inaccuracy in strain quantification underestimated significant strain development at early systole in dobutamine-stimulated hearts. CONCLUSION The HARP-based method developed in the current study enabled automated restoration of undeformed taglines in mouse hearts, leading to more accurate calculation of myocardial wall strain and torsion during dobutamine stimulation.
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Affiliation(s)
- Wei Li
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44122, USA
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Bachner-Hinenzon N, Ertracht O, Leitman M, Vered Z, Shimoni S, Beeri R, Binah O, Adam D. Layer-specific strain analysis by speckle tracking echocardiography reveals differences in left ventricular function between rats and humans. Am J Physiol Heart Circ Physiol 2010; 299:H664-72. [DOI: 10.1152/ajpheart.00017.2010] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The rat heart is commonly used as an experimental model of the human heart in both health and disease states, assuming that heart function of rats and humans is alike. When studying a rat model, echocardiography is usually performed on sedated rats, whereas standard echocardiography on adult humans does not require any sedation. Since echocardiography results of sedated rats are usually inferred to alert humans, in the present study, we tested the hypothesis that differences in left ventricular (LV) function may be present between rats sedated by a low dose of ketamine-xylazine and alert humans. Echocardiography was applied to 110 healthy sedated rats and 120 healthy alert humans. Strain parameters were calculated from the scans using a layer-specific speckle tracking echocardiography program. The results showed that layer longitudinal strain is equal in rats and humans, whereas segmental strain is heterogeneous ( P < 0.05) in a different way in rats and humans ( P < 0.05). Furthermore, layer circumferential strain is larger in humans ( P < 0.001), and the segmental results showed different segmental heterogeneity in rats and humans ( P < 0.05). Radial strain was found to be homogeneous at the apex and papillary muscle levels in humans and heterogeneous in rats ( P < 0.001). Additionally, whereas LV twist was equal in rats and humans, in rats the rotation was larger at the apex ( P < 0.01) and smaller at the base ( P < 0.001). The torsion-to-shortening ratio parameter, which indicates the transmural distribution of contractile myofibers, was found to be equal in rats and humans. Thus, when evaluating LV function of sedated rats under ketamine-xylazine, it is recommended to measure the global longitudinal strain, LV twist, and torsion-to-shortening ratio, since no scaling is required when converting these parameters and inferring them to humans.
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Affiliation(s)
| | - Offir Ertracht
- Department of Physiology, Ruth and Bruce Rappaport Faculty of Medicine, and
- Rappaport Family Institute for Research in the Medical Sciences, Technion-Israel Institute of Technology, Haifa
| | - Marina Leitman
- Department of Cardiology, Assaf Harofeh Medical Center, Zerifin
- Sackler School of Medicine, Tel Aviv University, Tel Aviv
| | - Zvi Vered
- Department of Cardiology, Assaf Harofeh Medical Center, Zerifin
- Sackler School of Medicine, Tel Aviv University, Tel Aviv
| | - Sara Shimoni
- Department of Cardiology, Kaplan Medical Center, Rehovot; and
| | - Ronen Beeri
- The Cardiovascular Research Center, Heart Institute, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Ofer Binah
- Department of Physiology, Ruth and Bruce Rappaport Faculty of Medicine, and
- Rappaport Family Institute for Research in the Medical Sciences, Technion-Israel Institute of Technology, Haifa
| | - Dan Adam
- Faculty of Biomedical Engineering and
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Zhong J, Yu X. Strain and torsion quantification in mouse hearts under dobutamine stimulation using 2D multiphase MR DENSE. Magn Reson Med 2010; 64:1315-22. [PMID: 20740659 DOI: 10.1002/mrm.22530] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Revised: 05/13/2010] [Accepted: 05/17/2010] [Indexed: 11/08/2022]
Abstract
In this study, a 2D multiphase magnetic resonance displacement encoding with stimulated echoes (DENSE) imaging and analysis method was developed for direct quantification of Lagrangian strain in the mouse heart. Using the proposed method, <10 ms temporal resolution and 0.56 mm in-plane resolution were achieved. A validation study that compared strain calculation by displacement encoding with stimulated echoes and by magnetic resonance tagging showed high correlation between the two methods (R(2) > 0.80). Regional ventricular wall strain and twist were characterized in mouse hearts at baseline and under dobutamine stimulation. Dobutamine stimulation induced significant increase in radial and circumferential strains and torsion at peak systole. A rapid untwisting was also observed during early diastole. This work demonstrates the capability of characterizing cardiac functional response to dobutamine stimulation in the mouse heart using 2D multiphase magnetic resonance displacement encoding with stimulated echoes.
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Affiliation(s)
- Jia Zhong
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
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Chen Y, Somji A, Yu X, Stelzer JE. Altered in vivo left ventricular torsion and principal strains in hypothyroid rats. Am J Physiol Heart Circ Physiol 2010; 299:H1577-87. [PMID: 20729398 DOI: 10.1152/ajpheart.00406.2010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The twisting and untwisting motions of the left ventricle (LV) lead to efficient ejection of blood during systole and filling of the ventricle during diastole. Global LV mechanical performance is dependent on the contractile properties of cardiac myocytes; however, it is not known how changes in contractile protein expression affect the pattern and timing of LV rotation. At the myofilament level, contractile performance is largely dependent on the isoforms of myosin heavy chain (MHC) that are expressed. Therefore, in this study, we used MRI to examine the in vivo mechanical consequences of altered MHC isoform expression by comparing the contractile properties of hypothyroid rats, which expressed only the slow β-MHC isoform, and euthyroid rats, which predominantly expressed the fast α-MHC isoform. Unloaded shortening velocity (V(o)) and apparent rate constants of force development (k(tr)) were measured in the skinned ventricular myocardium isolated from euthyroid and hypothyroid hearts. Increased expression of β-MHC reduced LV torsion and fiber strain and delayed the development of peak torsion and strain during systole. Depressed in vivo mechanical performance in hypothyroid rats was related to slowed cross-bridge performance, as indicated by significantly slower V(o) and k(tr), compared with euthyroid rats. Dobutamine infusion in hypothyroid hearts produced smaller increases in torsion and strain and aberrant transmural torsion patterns, suggesting that the myocardial response to β-adrenergic stress is compromised. Thus, increased expression of β-MHC alters the pattern and decreases the magnitude of LV rotation, contributing to reduced mechanical performance during systole, especially in conditions of increased workload.
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Affiliation(s)
- Yong Chen
- Department of Biomedical Engineering, School of Engineering, Case Western Reserve University, Cleveland, Ohio 44106, USA
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Wu Y, Wu EX. MR investigation of the coupling between myocardial fiber architecture and cardiac contraction. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2010; 2009:4395-8. [PMID: 19964360 DOI: 10.1109/iembs.2009.5333688] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Left ventricular structure has proved to be related with cardiac function; however the relation of myocardial fiber distribution with regional wall motion remains to be elucidated. In this study, both in vivo tagging and ex vivo DTI studies were performed in adult rats. LV circumferential strain, myocardium twist and myocardial fiber architecture were investigated. Results show that myocardial fiber distribution has direct relation with LV myocardium magnitude of circumferential strain and twist angle. Such integrated functional and structural analysis may provide more information for understanding the fundamental cardiac mechanics and assessment of pathological changes.
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Affiliation(s)
- Yin Wu
- Dept. of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong
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MAI WILFRIED, WEISSE CHICK, SLEEPER MEGM. CARDIAC MAGNETIC RESONANCE IMAGING IN NORMAL DOGS AND TWO DOGS WITH HEART BASE TUMOR. Vet Radiol Ultrasound 2010; 51:428-35. [DOI: 10.1111/j.1740-8261.2010.01673.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Frank LH, Yu Q, Francis R, Tian X, Samtani R, Sahn DJ, Leatherbury L, Lo CW. Ventricular rotation is independent of cardiac looping: a study in mice with situs inversus totalis using speckle-tracking echocardiography. J Am Soc Echocardiogr 2010; 23:315-23. [PMID: 20097527 DOI: 10.1016/j.echo.2009.11.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Indexed: 11/17/2022]
Abstract
BACKGROUND The authors conducted an ultrasound interrogation of a mutant mouse model with a Dnah5 mutation to determine whether cardiac mechanics may be affected by reversal of cardiac situs. This mutant is a bona fide model of primary ciliary dyskinesia, with surviving homozygous mice showing either situs solitus (SS) or situs inversus totalis (SI). METHODS High-frequency ultrasound interrogations of 27 neonatal and infant Dnah5 mutant mice, 16 with SS and 11 with SI, were conducted using an ultra-high-frequency biomicroscope. Electrocardiographic and respiratory gating were used to reconstruct high-resolution two-dimensional cines at 1,000 Hz, with speckle-tracking echocardiography used to further analyze midchamber and apical rotation. RESULTS All SS mice exhibited the expected counterclockwise apical rotation as viewed caudocranially, and surprisingly, the same counterclockwise motion was also observed in SI mice. Speckle-tracking analysis confirmed counterclockwise systolic rotation in both SS and SI mice, and this increased in magnitude from the subepicardium to the endocardium and from the papillary muscles to the apex. The magnitude of apical endocardial rotation was not different for SS and SI mice (5.64+/-0.75 degrees and 5.76+/-1.90 degrees, respectively, P=.93). The anatomic segments responsible for the largest components of apical endocardial systolic rotation differed between the SS and SI hearts (P=.004). In both, the two largest contributors to rotation were offset 180 degrees from each other, but the anatomic regions differed between them. In SS hearts, maximal regional rotation occurred at the anterior mid-septum and posterolateral free wall, while in SI hearts, it was derived from the posterior septum and the anterolateral free wall. Analysis by episcopic fluorescence image capture histology of representative SI and SS mice showed normal intracardiac and segmental anatomy ({S,D,S} or {I,L,I}) without intracardiac defects. CONCLUSIONS These results show that mirror-image cardiac looping did not result in mirror-image rotation of the morphologic left ventricle. These findings suggest that further studies are warranted to evaluate whether fiber orientation and cardiac mechanics may be abnormal in individuals with reversal of cardiac situs. The results of this study indicate that cardiac looping and myofiber orientation may be independently regulated.
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Affiliation(s)
- Lowell H Frank
- Laboratory of Developmental Biology, Office of Biostatistics Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA.
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Li W, Liu W, Zhong J, Yu X. Early manifestation of alteration in cardiac function in dystrophin deficient mdx mouse using 3D CMR tagging. J Cardiovasc Magn Reson 2009; 11:40. [PMID: 19849858 PMCID: PMC2774673 DOI: 10.1186/1532-429x-11-40] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Accepted: 10/22/2009] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Duchenne muscular dystrophy (DMD) is caused by the absence of the cytoskeletal protein, dystrophin. In DMD patients, dilated cardiomyopathy leading to heart failure may occur during adolescence. However, early cardiac dysfunction is frequently undetected due to physical inactivity and generalized debilitation. The objective of this study is to determine the time course of cardiac functional alterations in mdx mouse, a mouse model of DMD, by evaluating regional ventricular function with CMR tagging. METHODS In vivo myocardial function was evaluated by 3D CMR tagging in mdx mice at early (2 months), middle (7 months) and late (10 months) stages of disease development. Global cardiac function, regional myocardial wall strains, and ventricular torsion were quantified. Myocardial lesions were assessed with Masson's trichrome staining. RESULTS Global contractile indexes were similar between mdx and C57BL/6 mice in each age group. Histology analysis showed that young mdx mice were free of myocardial lesions. Interstitial fibrosis was present in 7 month mdx mice, with further development into patches or transmural lesions at 10 months of age. As a result, 10 month mdx mice showed significantly reduced regional strain and torsion. However, young mdx mice showed an unexpected increase in regional strain and torsion, while 7 month mdx mice displayed similar regional ventricular function as the controls. CONCLUSION Despite normal global ventricular function, CMR tagging detected a biphasic change in myocardial wall strain and torsion, with an initial increase at young age followed by progressive decrease at older ages. These results suggest that CMR tagging can provide more sensitive measures of functional alterations than global functional indexes in dystrophin-related cardiomyopathies.
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MESH Headings
- Age Factors
- Aging
- Animals
- Cardiac Output
- Cardiomyopathy, Dilated/etiology
- Cardiomyopathy, Dilated/pathology
- Cardiomyopathy, Dilated/physiopathology
- Disease Models, Animal
- Disease Progression
- Fibrosis
- Image Interpretation, Computer-Assisted
- Imaging, Three-Dimensional
- Magnetic Resonance Imaging, Cine
- Mice
- Mice, Inbred C57BL
- Mice, Inbred mdx
- Muscular Dystrophy, Duchenne/complications
- Muscular Dystrophy, Duchenne/pathology
- Muscular Dystrophy, Duchenne/physiopathology
- Myocardial Contraction
- Myocardium/pathology
- Stroke Volume
- Time Factors
- Torsion, Mechanical
- Ventricular Function, Left
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Affiliation(s)
- Wei Li
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
- Case Center for Imaging Research, Case Western Reserve University, Cleveland, Ohio, USA
| | - Wei Liu
- Department of Biomedical Engineering, Washington University, St Louis, Missouri, USA
| | - Jia Zhong
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
- Case Center for Imaging Research, Case Western Reserve University, Cleveland, Ohio, USA
| | - Xin Yu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
- Department of Radiology, Case Western Reserve University, Cleveland, Ohio, USA
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio, USA
- Case Center for Imaging Research, Case Western Reserve University, Cleveland, Ohio, USA
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Zhong J, Liu W, Yu X. Transmural myocardial strain in mouse: quantification of high-resolution MR tagging using harmonic phase (HARP) analysis. Magn Reson Med 2009; 61:1368-73. [PMID: 19319888 DOI: 10.1002/mrm.21942] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
MR tagging allows noninvasive examination of regional myocardial function with high accuracy and reproducibility. The current tagging method is limited by low tagging resolution for accurate transmural strain quantification. Previously, a spatial modulation of magnetization (SPAMM)-based method was proposed to increase the tagging resolution by combining two or more tagged images with different tagging grid positions. However, there has been limited application due to the challenge in image processing of multiple data sets. In the current study, we propose a harmonic phase (HARP)-based method for automated and fast analysis of high tagging resolution images. First-order harmonic peaks from low tagging resolution images were combined to generate the composite second-order harmonic peak for strain computation. The combined images reached a tagging resolution of 0.3 mm. The proposed method was applied to the quantification of transmural myocardial wall strain in seven normal C57BL/6 mice. Principal strains, as well as radial and circumferential strains, were quantified using the current method.
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Affiliation(s)
- Jia Zhong
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44122, USA
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Strijkers GJ, Bouts A, Blankesteijn WM, Peeters THJM, Vilanova A, van Prooijen MC, Sanders HMHF, Heijman E, Nicolay K. Diffusion tensor imaging of left ventricular remodeling in response to myocardial infarction in the mouse. NMR IN BIOMEDICINE 2009; 22:182-190. [PMID: 18780284 DOI: 10.1002/nbm.1299] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The cardiac muscle architecture lies at the basis of the mechanical and electrical properties of the heart, and dynamic alterations in fiber structure are known to be of prime importance in healing and remodeling after myocardial infarction. In this study, left ventricular remodeling was characterized using diffusion tensor imaging (DTI) in a mouse model of myocardial infarction. Myocardial infarction was induced in mice by permanent ligation of the left anterior descending coronary artery. Serial ex vivo DTI measurements were performed 7, 14, 28, and 60 days after ligation. Apparent diffusion coefficient, fractional anisotropy, the three eigenvalues of the diffusion tensor, and the myofiber disarray served as readout parameters. After myocardial infarction, the mouse hearts displayed extreme wall thinning in the infarcted area, which covered large parts of the apex and extended into the free wall up to the equator. Average heart mass increased by 70% 7-60 days after infarction. Histological analysis showed that the infarct at 7 days consisted of unstructured tissue with residual necrosis and infiltration of macrophages and myofibroblasts. At 14 days after infarction, the necrotic tissue had disappeared and collagen fibers were starting to appear. From 28 to 60 days, the infarct had fully developed into a mature scar. DTI parameters showed dynamic changes as a function of time after infarction. The apparent diffusion coefficient in the infarcted region was lower than in remote regions and increased as a function of time after infarction. The fractional anisotropy was higher in the infarcted region and was maximum at 28 days, which was attributed to the development of structured collagen fibers. Myofiber disarray, which was analyzed by considering the alignment of fibers in neighboring voxels, was significantly higher in infarcted regions. DTI provides a valuable non-destructive tool for characterizing structural remodeling in diseased myocardium.
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Affiliation(s)
- Gustav J Strijkers
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands.
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Daire JL, Jacob JP, Hyacinthe JN, Croisille P, Montet-Abou K, Richter S, Botsikas D, Lepetit-Coiffé M, Morel D, Vallée JP. Cine and tagged cardiovascular magnetic resonance imaging in normal rat at 1.5 T: a rest and stress study. J Cardiovasc Magn Reson 2008; 10:48. [PMID: 18980685 PMCID: PMC2590601 DOI: 10.1186/1532-429x-10-48] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2008] [Accepted: 11/03/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The purpose of this study was to measure regional contractile function in the normal rat using cardiac cine and tagged cardiovascular magnetic resonance (CMR) during incremental low doses of dobutamine and at rest. METHODS Five rats were investigated for invasive left ventricle pressure measurements and five additional rats were imaged on a clinical 1.5 T MR system using a cine sequence (11-20 phases per cycle, 0.28/0.28/2 mm) and a C-SPAMM tag sequence (18-25 phases per cycle, 0.63/1.79/3 mm, tag spacing 1.25 mm). For each slice, wall thickening (WT) and circumferential strains (CS) were calculated at rest and at stress (2.5, 5 and 10 microg/min/kg of dobutamine). RESULTS Good cine and tagged images were obtained in all the rats even at higher heart rate (300-440 bpm). Ejection fraction and left ventricular (LV) end-systolic volume showed significant changes after each dobutamine perfusion dose (p < 0.001). Tagged CMR had the capacity to resolve the CS transmural gradient and showed a significant increase of both WT and CS at stress compared to rest. Intra and interobserver study showed less variability for the tagged technique. In rats in which a LV catheter was placed, dobutamine produced a significant increase of heart rate, LV dP/dtmax and LV pressure significantly already at the lowest infusion dose. CONCLUSION Robust cardiac cine and tagging CMR measurements can be obtained in the rat under incremental dobutamine stress using a clinical 1.5 T MR scanner.
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Affiliation(s)
- Jean-Luc Daire
- Radiology Department, Faculty of Medicine, University of Geneva and Geneva University Hospital, CH-1211 Geneva 14, Switzerland
| | - Jean-Pascal Jacob
- Radiology Department, Faculty of Medicine, University of Geneva and Geneva University Hospital, CH-1211 Geneva 14, Switzerland
| | - Jean-Noel Hyacinthe
- Radiology Department, Faculty of Medicine, University of Geneva and Geneva University Hospital, CH-1211 Geneva 14, Switzerland
| | - Pierre Croisille
- Radiology Department, Hopital L. Pradel, CREATIS UMR CNRS 5515 & INSERM U630 UCB, Lyon I, France
| | - Karin Montet-Abou
- Radiology Department, Faculty of Medicine, University of Geneva and Geneva University Hospital, CH-1211 Geneva 14, Switzerland
| | - Sophie Richter
- Radiology Department, Faculty of Medicine, University of Geneva and Geneva University Hospital, CH-1211 Geneva 14, Switzerland
| | - Diomidis Botsikas
- Radiology Department, Faculty of Medicine, University of Geneva and Geneva University Hospital, CH-1211 Geneva 14, Switzerland
| | - Matthieu Lepetit-Coiffé
- Radiology Department, Faculty of Medicine, University of Geneva and Geneva University Hospital, CH-1211 Geneva 14, Switzerland
| | - Denis Morel
- Anesthesiology, Pharmacology and Intensive Care Department, Faculty of Medicine, University of Geneva and Geneva University Hospitals, CH-1211, Geneva 14, Switzerland
| | - Jean-Paul Vallée
- Radiology Department, Faculty of Medicine, University of Geneva and Geneva University Hospital, CH-1211 Geneva 14, Switzerland
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