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Lantz J, Bäck S, Carlhäll CJ, Bolger A, Persson A, Karlsson M, Ebbers T. Impact of prosthetic mitral valve orientation on the ventricular flow field: Comparison using patient-specific computational fluid dynamics. J Biomech 2020; 116:110209. [PMID: 33422725 DOI: 10.1016/j.jbiomech.2020.110209] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 12/10/2020] [Accepted: 12/14/2020] [Indexed: 11/29/2022]
Abstract
Significant mitral valve regurgitation creates progressive adverse remodeling of the left ventricle (LV). Replacement of the failing valve with a prosthesis generally improves patient outcomes but leaves the patient with non-physiological intracardiac flow patterns that might contribute to their future risk of thrombus formation and embolism. It has been suggested that the angular orientation of the implanted valve might modify the postoperative distortion of the intraventricular flow field. In this study, we investigated the effect of prosthetic valve orientation on LV flow patterns by using heart geometry from a patient with LV dysfunction and a competent native mitral valve to calculate intracardiac flow fields with computational fluid dynamics (CFD). Results were validated using in vivo 4D Flow MRI. The computed flow fields were compared to calculations following virtual implantation of a mechanical heart valve oriented in four different angles to assess the effect of leaflet position. Flow patterns were visualized in long- and short-axes and quantified with flow component analysis. In comparison to a native valve, valve implantation increased the proportion of the mitral inflow remaining in the basal region and further increased the residual volume in the apical area. Only slight changes due to valve orientation were observed. Using our numerical framework, we demonstrated quantitative changes in left ventricular blood flow due to prosthetic mitral replacement. This framework may be used to improve design of prosthetic heart valves and implantation procedures to minimize the potential for apical flow stasis, and potentially assist personalized treatment planning.
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Affiliation(s)
- Jonas Lantz
- Division of Cardiovascular Medicine, Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden; Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
| | - Sophia Bäck
- Division of Cardiovascular Medicine, Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden; Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
| | - Carl-Johan Carlhäll
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden; Department of Clinical Physiology in Linköping, and Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Ann Bolger
- Department of Clinical Physiology in Linköping, and Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden; Department of Medicine, University of California, San Francisco, United States
| | - Anders Persson
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden; Division of Radiology, Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Matts Karlsson
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden; Division of Applied Thermodynamics and Fluid Mechanics, Department of Management and Engineering, Linköping University, Sweden
| | - Tino Ebbers
- Division of Cardiovascular Medicine, Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden; Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden.
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Khoche S, Gu W, Cobey F. Inverted Aortic Prosthesis in the Mitral Position: Is Upside Down Always the Right Side Up? J Cardiothorac Vasc Anesth 2019; 33:3204-3210. [DOI: 10.1053/j.jvca.2019.03.035] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Revised: 03/15/2019] [Accepted: 03/18/2019] [Indexed: 11/11/2022]
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Lunkenheimer PP, Niederer P, Stephenson RS, Redmann K, Batista RV, Smerup M, Anderson RH. What is the clinical significance of ventricular mural antagonism? Eur J Cardiothorac Surg 2019; 53:714-723. [PMID: 29136124 DOI: 10.1093/ejcts/ezx382] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 10/01/2017] [Indexed: 11/15/2022] Open
Abstract
Recent morphological studies provide evidence that the ventricular walls are arranged as a 3D meshwork of aggregated cardiomyocyte chains, exhibiting marked local structural variations. In contrary to previous findings, up to two-fifths of the chains are found to have a partially transmural alignment, thus deviating from the prevailing tangential orientation. Upon contraction, they produce, in addition to a tangential force, a radial force component that counteracts ventricular constriction and aids widening of the ventricular cavity. In experimental studies, we have provided evidence for the existence of such forces, which are auxotonic in nature. This is in contrast to the tangentially aligned myocytes that produce constrictive forces, which are unloading in nature. The ventricular myocardium is, therefore, able to function in an antagonistic fashion, with the prevailing constrictive forces acting simultaneously with a dilatory force component. The ratio of constrictive to dilating force varies locally according to the specific mural architecture. Such antagonism acts according to local demands to preserve the ventricular shape, store the elastic energy that drives the fast late systolic dilation and apportion mural motion to facilitate the spiralling nature of intracavitary flow. Intracavitary pressure and flow dynamics are thus governed concurrently by ventricular constrictive and dilative force components. Antagonistic activity, however, increases deleteriously in states of cardiac disease, such as hypertrophy and fibrosis. ß-blockade at low dosage acts selectively to temper the auxotonic forces.
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Affiliation(s)
- Paul P Lunkenheimer
- Department of Experimental Cardiac- and Thoraco-Vascular Surgery, University Hospital Muenster, Muenster, Germany
| | - Peter Niederer
- Institute of Biomedical Engineering, ETH, University of Zurich, Zurich, Switzerland
| | - Robert S Stephenson
- Comparative Medicine Laboratory, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Klaus Redmann
- Department of Experimental Cardiac- and Thoraco-Vascular Surgery, University Hospital Muenster, Muenster, Germany
| | | | - Morten Smerup
- University Hospital, Thoraxkirurgisk Klinik, Copenhagen, Denmark
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Lunkenheimer PP, Niederer P, Lunkenheimer JM, Keller H, Redmann K, Smerup M, Anderson RH. [The antagonistic function of the heart muscle sustains the autoregulation according to Frank and Starling : Part I: Structure and function of heart muscle]. Herz 2018; 45:170-177. [PMID: 30054713 DOI: 10.1007/s00059-018-4734-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 07/05/2018] [Indexed: 10/28/2022]
Abstract
In the tradition of Harvey and according to Otto Frank the heart muscle structure is arranged in a strictly tangential fashion hence all contractile forces act in the direction of ventricular ejection. In contrast, morphology confirms that the heart consists of a 3-dimensional network of muscle fibers with up to two fifths of the chains of aggregated myocytes deviating from a tangential alignment at variable angles. Accordingly, the myocardial systolic forces contain, in addition to a constrictive also a (albeit smaller) radially acting component. Using needle force probes we have correspondingly measured an unloading type of force in a tangential direction and an auxotonic type in dilatative transversal direction of the ventricular walls to show that the myocardial body contracts actively in a 3-dimensional pattern. This antagonism supports the autoregulation of heart muscle function according to Frank and Starling, preserving ventricular shape, enhances late systolic fast dilation and attenuates systolic constriction of the ventricle wall. Auxotonic dilating forces are particularly sensitive to inotropic medication. Low dose beta-blocker is able to attenuate the antagonistic activity. All myocardial components act against four components of afterload, the hemodynamic, the myostructural, the stromatogenic and the hydraulic component. This complex interplay critically complicates clinical diagnostics. Clinical implications are far-reaching (see Part II, https://doi.org/10.1007/s00059-018-4735-x).
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Affiliation(s)
- P P Lunkenheimer
- Experimentelle Thorax‑, Herz- und Gefäßchirurgie, Universitätskliniken Münster, Münster, Deutschland.
| | - P Niederer
- Institute of Biomedical Engineering, ETH and University Zürich, Zürich, Schweiz
| | - J M Lunkenheimer
- Krankenhaus der Augustinerinnen/Severinsklösterchen, Jakobstr. 27-31, Köln, Deutschland
| | - H Keller
- Klinik Hirslanden, Zürich, Schweiz
| | - K Redmann
- Universitätskliniken, Münster, Deutschland
| | - M Smerup
- Thoraxkirurgisk Klinik, University Hospital, Kopenhagen, Dänemark
| | - R H Anderson
- Institute of Genetic Medicine, Newcastle University, Newcastle, Großbritannien
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5
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Post-operative ventricular flow dynamics following atrioventricular valve surgical and device therapies: A review. Med Eng Phys 2018; 54:1-13. [DOI: 10.1016/j.medengphy.2018.01.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 12/17/2017] [Accepted: 01/28/2018] [Indexed: 01/26/2023]
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Suchá D, Symersky P, Tanis W, Mali WP, Leiner T, van Herwerden LA, Budde RP. Multimodality Imaging Assessment of Prosthetic Heart Valves. Circ Cardiovasc Imaging 2015; 8:e003703. [DOI: 10.1161/circimaging.115.003703] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Echocardiography and fluoroscopy are the main techniques for prosthetic heart valve (PHV) evaluation, but because of specific limitations they may not identify the morphological substrate or the extent of PHV pathology. Cardiac computed tomography (CT) and magnetic resonance imaging (MRI) have emerged as new potential imaging modalities for valve prostheses. We present an overview of the possibilities and pitfalls of CT and MRI for PHV assessment based on a systematic literature review of all experimental and patient studies. For this, a comprehensive systematic search was performed in PubMed and Embase on March 24, 2015, containing CT/MRI and PHV synonyms. Our final selection yielded 82 articles on surgical valves. CT allowed adequate assessment of most modern PHVs and complemented echocardiography in detecting the obstruction cause (pannus or thrombus), bioprosthesis calcifications, and endocarditis extent (valve dehiscence and pseudoaneurysms). No clear advantage over echocardiography was found for the detection of vegetations or periprosthetic regurgitation. Whereas MRI metal artifacts may preclude direct prosthesis analysis, MRI provided information on PHV-related flow patterns and velocities. MRI demonstrated abnormal asymmetrical flow patterns in PHV obstruction and allowed prosthetic regurgitation assessment. Hence, CT shows great clinical relevance as a complementary imaging tool for the diagnostic work-up of patients with suspected PHV obstruction and endocarditis. MRI shows potential for functional PHV assessment although more studies are required to provide diagnostic reference values to allow discrimination of normal from pathological conditions.
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Affiliation(s)
- Dominika Suchá
- From the Departments of Radiology (D.S., W.P.Th.M.M., T.L., R.P.J.B.) and Cardiothoracic Surgery (L.A.v.H.), University Medical Center Utrecht, Utrecht, The Netherlands; Department of Cardiothoracic Surgery, VU University Medical Center, Amsterdam, The Netherlands (P.S.); Department of Cardiology, HagaZiekenhuis, The Hague, The Netherlands (W.T.); and Department of Radiology, Erasmus Medical Center, Rotterdam, The Netherlands (R.P.J.B.)
| | - Petr Symersky
- From the Departments of Radiology (D.S., W.P.Th.M.M., T.L., R.P.J.B.) and Cardiothoracic Surgery (L.A.v.H.), University Medical Center Utrecht, Utrecht, The Netherlands; Department of Cardiothoracic Surgery, VU University Medical Center, Amsterdam, The Netherlands (P.S.); Department of Cardiology, HagaZiekenhuis, The Hague, The Netherlands (W.T.); and Department of Radiology, Erasmus Medical Center, Rotterdam, The Netherlands (R.P.J.B.)
| | - W. Tanis
- From the Departments of Radiology (D.S., W.P.Th.M.M., T.L., R.P.J.B.) and Cardiothoracic Surgery (L.A.v.H.), University Medical Center Utrecht, Utrecht, The Netherlands; Department of Cardiothoracic Surgery, VU University Medical Center, Amsterdam, The Netherlands (P.S.); Department of Cardiology, HagaZiekenhuis, The Hague, The Netherlands (W.T.); and Department of Radiology, Erasmus Medical Center, Rotterdam, The Netherlands (R.P.J.B.)
| | - Willem P.Th.M. Mali
- From the Departments of Radiology (D.S., W.P.Th.M.M., T.L., R.P.J.B.) and Cardiothoracic Surgery (L.A.v.H.), University Medical Center Utrecht, Utrecht, The Netherlands; Department of Cardiothoracic Surgery, VU University Medical Center, Amsterdam, The Netherlands (P.S.); Department of Cardiology, HagaZiekenhuis, The Hague, The Netherlands (W.T.); and Department of Radiology, Erasmus Medical Center, Rotterdam, The Netherlands (R.P.J.B.)
| | - Tim Leiner
- From the Departments of Radiology (D.S., W.P.Th.M.M., T.L., R.P.J.B.) and Cardiothoracic Surgery (L.A.v.H.), University Medical Center Utrecht, Utrecht, The Netherlands; Department of Cardiothoracic Surgery, VU University Medical Center, Amsterdam, The Netherlands (P.S.); Department of Cardiology, HagaZiekenhuis, The Hague, The Netherlands (W.T.); and Department of Radiology, Erasmus Medical Center, Rotterdam, The Netherlands (R.P.J.B.)
| | - Lex A. van Herwerden
- From the Departments of Radiology (D.S., W.P.Th.M.M., T.L., R.P.J.B.) and Cardiothoracic Surgery (L.A.v.H.), University Medical Center Utrecht, Utrecht, The Netherlands; Department of Cardiothoracic Surgery, VU University Medical Center, Amsterdam, The Netherlands (P.S.); Department of Cardiology, HagaZiekenhuis, The Hague, The Netherlands (W.T.); and Department of Radiology, Erasmus Medical Center, Rotterdam, The Netherlands (R.P.J.B.)
| | - Ricardo P.J. Budde
- From the Departments of Radiology (D.S., W.P.Th.M.M., T.L., R.P.J.B.) and Cardiothoracic Surgery (L.A.v.H.), University Medical Center Utrecht, Utrecht, The Netherlands; Department of Cardiothoracic Surgery, VU University Medical Center, Amsterdam, The Netherlands (P.S.); Department of Cardiology, HagaZiekenhuis, The Hague, The Netherlands (W.T.); and Department of Radiology, Erasmus Medical Center, Rotterdam, The Netherlands (R.P.J.B.)
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Altered left ventricular vortex ring formation by 4-dimensional flow magnetic resonance imaging after repair of atrioventricular septal defects. J Thorac Cardiovasc Surg 2015; 150:1233-40.e1. [PMID: 26282608 DOI: 10.1016/j.jtcvs.2015.07.048] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 07/01/2015] [Accepted: 07/15/2015] [Indexed: 11/22/2022]
Abstract
OBJECTIVES During normal left ventricular (LV) filling, a vortex ring structure is formed distal to the left atrioventricular valve (LAVV). Vortex structures contribute to efficient flow organization. We aimed to investigate whether LAVV abnormality in patients with a corrected atrioventricular septal defect (AVSD) has an impact on vortex ring formation. METHODS Whole-heart 4D flow MRI was performed in 32 patients (age: 26 ± 12 years), and 30 healthy subjects (age: 25 ± 14 years). Vortex ring cores were detected at peak early (E-peak) and peak late filling (A-peak). When present, the 3-dimensional position and orientation of the vortex ring was defined, and the circularity index was calculated. Through-plane flow over the LAVV, and the vortex formation time (VFT), were quantified to analyze the relationship of vortex flow with the inflow jet. RESULTS Absence of a vortex ring during E-peak (healthy subjects 0%, vs patients 19%; P = .015), and A-peak (healthy subjects 10% vs patients 44%; P = .008) was more frequent in patients. In 4 patients, this was accompanied by a high VFT (5.1-7.8 vs 2.4 ± 0.6 in healthy subjects), and in another 2 patients with abnormal valve anatomy. In patients compared with controls, the vortex cores had a more-anterior and apical position, closer to the ventricular wall, with a more-elliptical shape and oblique orientation. The shape of the vortex core closely resembled the valve shape, and its orientation was related to the LV inflow direction. CONCLUSIONS This study quantitatively shows the influence of abnormal LAVV and LV inflow on 3D vortex ring formation during LV inflow in patients with corrected AVSD, compared with healthy subjects.
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8
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Westerdale JC, Adrian R, Squires K, Chaliki H, Belohlavek M. Effects of Bileaflet Mechanical Mitral Valve Rotational Orientation on Left Ventricular Flow Conditions. Open Cardiovasc Med J 2015; 9:62-8. [PMID: 26312080 PMCID: PMC4541318 DOI: 10.2174/1874192401509010062] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 05/10/2015] [Accepted: 05/12/2015] [Indexed: 11/22/2022] Open
Abstract
We studied left ventricular flow patterns for a range of rotational orientations of a bileaflet mechanical heart valve (MHV) implanted in the mitral position of an elastic model of a beating left ventricle (LV). The valve was rotated through 3 angular positions (0, 45, and 90 degrees) about the LV long axis. Ultrasound scans of the elastic LV were obtained in four apical 2-dimensional (2D) imaging projections, each with 45 degrees of separation. Particle imaging velocimetry was performed during the diastolic period to quantify the in-plane velocity field obtained by computer tracking of diluted microbubbles in the acquired ultrasound projections. The resulting velocity field, vorticity, and shear stresses were statistically significantly altered by angular positioning of the mechanical valve, although the results did not show any specific trend with the valve angular position and were highly dependent on the orientation of the imaging plane with respect to the valve. We conclude that bileaflet MHV orientation influences hemodynamics of LV filling. However, determination of ‘optimal’ valve orientation cannot be made without measurement techniques that account for the highly 3-dimensional (3D) intraventricular flow.
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Affiliation(s)
- John C Westerdale
- School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, Arizona, USA
| | - Ronald Adrian
- School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, Arizona, USA
| | - Kyle Squires
- School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, Arizona, USA
| | - Hari Chaliki
- Division of Cardiovascular Disease, Mayo Clinic, Scottsdale, Arizona, USA
| | - Marek Belohlavek
- Division of Cardiovascular Disease, Mayo Clinic, Scottsdale, Arizona, USA
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Maisano F, Alfieri O, Banai S, Buchbinder M, Colombo A, Falk V, Feldman T, Franzen O, Herrmann H, Kar S, Kuck KH, Lutter G, Mack M, Nickenig G, Piazza N, Reisman M, Ruiz CE, Schofer J, Søndergaard L, Stone GW, Taramasso M, Thomas M, Vahanian A, Webb J, Windecker S, Leon MB. The future of transcatheter mitral valve interventions: competitive or complementary role of repair vs. replacement? Eur Heart J 2015; 36:1651-9. [PMID: 25870204 DOI: 10.1093/eurheartj/ehv123] [Citation(s) in RCA: 153] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Accepted: 03/23/2015] [Indexed: 11/14/2022] Open
Abstract
Transcatheter mitral interventions has been developed to address an unmet clinical need and may be an alternative therapeutic option to surgery with the intent to provide symptomatic and prognostic benefit. Beyond MitraClip therapy, alternative repair technologies are being developed to expand the transcatheter intervention armamentarium. Recently, the feasibility of transcatheter mitral valve implantation in native non-calcified valves has been reported in very high-risk patients. Acknowledging the lack of scientific evidence to date, it is difficult to predict what the ultimate future role of transcatheter mitral valve interventions will be. The purpose of the present report is to review the current state-of-the-art of mitral valve intervention, and to identify the potential future scenarios, which might benefit most from the transcatheter repair and replacement devices under development.
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Affiliation(s)
- Francesco Maisano
- University Hospital of Zurich, Rämistrasse 100, 8089-CH, Zurich, Switzerland
| | | | | | | | | | | | | | | | - Howard Herrmann
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - Saibal Kar
- Cedars Sinai Medical Center, Los Angeles, USA
| | | | | | | | | | | | - Mark Reisman
- University of Washington Medical Center, Washington, USA
| | - Carlos E Ruiz
- Lenox Hill Heart and Vascular Institute of New York, New York, USA
| | | | | | - Gregg W Stone
- Columbia University Medical Center, New York Presbyterian Hospital, New York, USA
| | - Maurizio Taramasso
- University Hospital of Zurich, Rämistrasse 100, 8089-CH, Zurich, Switzerland
| | - Martyn Thomas
- Guy's & St Thomas' Hospitals NHS Foundation Trust, London, UK
| | | | - John Webb
- St. Paul's Hospital, University of British Columbia, Vancouver, Canada
| | | | - Martin B Leon
- Columbia University Medical Center, New York Presbyterian Hospital, New York, USA
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Lunkenheimer PP, Niederer P, Sanchez-Quintana D, Murillo M, Smerup M. Models of ventricular structure and function reviewed for clinical cardiologists. J Cardiovasc Transl Res 2012; 6:176-86. [PMID: 23271645 DOI: 10.1007/s12265-012-9440-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 12/12/2012] [Indexed: 10/27/2022]
Abstract
The architectural arrangement of cardiomyocytes aggregated together within the ventricular walls remains controversial. Two models currently attract clinical attention, with neither model standing rigorous anatomical scrutiny. The first is based on the notion that ventricular mass can be unraveled consistently to produce a unique myocardial band. The second model was initially based on the notion that cardiomyocytes were bundled together in uniform fashion, with fibrous shelves interposed in transmural fashion. This concept was subsequently modified to accept the fact that the fibrous matrix supporting the cardiomyocytes within the ventricular walls does not form transmural sheets. Current observations demonstrate that not all cardiomyocytes are aggregated together in tangential fashion. A significant netting component is aligned in obliquely intruding and transversal fashion. The interaction between the tangential and transversal chains of cardiomyocytes with the fibrous matrix produces antagonistic forces, with both unloading and auxotonic forces necessary to explain normal and abnormal cardiodynamics. This article is part of a JCTR special issue on Cardiac Anatomy.
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Affiliation(s)
- Paul P Lunkenheimer
- Department of Experimental Thoraco-Vascular Surgery, Universitätsklinik, Münster, Domagkstraße 11, 48149 Münster, Germany.
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Jainandunsing JS, Mahmood F. High Transvalvular Gradients Across a Prosthetic Valve in the Mitral Position: Not Ignoring the Bigger Picture. J Cardiothorac Vasc Anesth 2012; 26:968-9. [DOI: 10.1053/j.jvca.2012.03.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Indexed: 11/11/2022]
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12
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Faludi R, Szulik M, D'hooge J, Herijgers P, Rademakers F, Pedrizzetti G, Voigt JU. Left ventricular flow patterns in healthy subjects and patients with prosthetic mitral valves: An in vivo study using echocardiographic particle image velocimetry. J Thorac Cardiovasc Surg 2010; 139:1501-10. [DOI: 10.1016/j.jtcvs.2009.07.060] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2008] [Revised: 06/10/2009] [Accepted: 07/06/2009] [Indexed: 10/19/2022]
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13
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Affiliation(s)
- Carl Johan Carlhäll
- Department of Clinical Physiology, University Hospital and Center for Medical Image Science and Visualization, Linköping University, Linköping, Sweden
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14
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Can we interpret the orientation of major or minor orifice in implanted tilting disc mechanical mitral valve on X-ray chest P-A view ? “The Sion Sign”. Indian J Thorac Cardiovasc Surg 2010. [DOI: 10.1007/s12055-009-0041-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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15
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Liu X, Weale P, Reiter G, Kino A, Dill K, Gleason T, Carroll T, Carr J. Breathhold time-resolved three-directional MR velocity mapping of aortic flow in patients after aortic valve-sparing surgery. J Magn Reson Imaging 2009; 29:569-75. [PMID: 19243038 DOI: 10.1002/jmri.21685] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
PURPOSE To evaluate the utility of breathhold time-resolved three-directional MR velocity mapping for quantifying the restoration of normal flow patterns in patients after aortic valve-sparing surgery. MATERIALS AND METHODS Breathhold time-resolved three-directional MR velocity mapping was performed on 13 patients with aortic valve-sparing surgery. Ten healthy volunteers and 12 patients with ascending aortic aneurysm underwent the same MR examination for comparison. Aortic laminar flow, turbulent flow, and the presence of vortical flow in the sinuses of Valsalva were semiquantitatively assessed and statistically compared between the three groups of subjects. RESULTS The average score of laminar flow in the ascending aorta for patients with surgery was not significantly different from that of volunteers (P=0.210), but was significantly greater than that of patients with aneurysm (P<0.01). The average score of turbulent flow in patients with surgery was significantly smaller than that of patients with aneurysm (P<0.01). The presence of systolic vortical flow in the sinuses of Valsalva for patients with surgery was not significantly different from that of healthy volunteers (P=0.405) and patients with aneurysm (P=0.238). CONCLUSION Breathhold time-resolved three-directional MR velocity mapping allows for quantifying flow patterns in the aortic root and ascending aorta. Normal laminar flow in the ascending aorta and vortical flow in the sinuses of Valsalva can be restored in patients after aortic valve-sparing surgery.
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Affiliation(s)
- Xin Liu
- Department of Radiology, Northwestern University, Chicago, Illinois 60611, USA
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Lunkenheimer PP, Redmann K, Niederer P, Schmid P, Smerup M, Stypmann J, Däbritz S, Rothaus K, Anderson RH. Models versus established knowledge in describing the functional morphology of the ventricular myocardium. Heart Fail Clin 2008; 4:273-88. [PMID: 18598980 DOI: 10.1016/j.hfc.2008.02.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The myocytes comprising the ventricular mass are arranged so as to function in antagonistic fashion, the walls having the capacity to generate both constrictive and dilatory forces. This dualistic activity is organized on the basis of a site-specific morphologic pattern, permitting marked regional specificity for mural motion and providing a target for regional therapy. Diseased regions can be removed surgically without danger of jeopardizing the remaining healthy mural segments. The sensitivity of the intruding population of myocytes to positive and negative inotropic medication is markedly more pronounced than that of the prevailing tangentially aligned myocytes. This asymmetrical action of inotropes in the setting of global ventricular imbalance promotes the potential to restore constrictive as opposed to dilatory actions.
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Watanabe H, Sugiura S, Hisada T. The looped heart does not save energy by maintaining the momentum of blood flowing in the ventricle. Am J Physiol Heart Circ Physiol 2008; 294:H2191-6. [DOI: 10.1152/ajpheart.00041.2008] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Previous studies suggested that the reconstruction or maintenance of physiological blood flow paths in the heart is important to obtain a good outcome following cardiac surgery, but this concept has no established theoretical foundation. We developed a multiscale, multiphysics heart simulator, based on the finite element method, and compared the hemodynamics of ventricles with physiological and nonphysiological flow paths. We found that the physiological flow path did not have an energy-saving effect but facilitated the separation of the outflow and inflow paths, so avoiding any mixing of the blood. The work performed by the ventricular wall was comparable at slower and faster heart rates (physiological vs. nonphysiological, 0.864 vs. 0.874 J, heart rate = 60 beats/min; and 0.599 vs. 0.590 J, heart rate = 100 beats/min), indicating that chiral asymmetry of the flow paths in the mammalian heart has minimal functional merit. At lower heart rates, the blood coming in the first beat was cleared almost completely by the ninth beat in both models. However, at high heart rates, such complete clearance was observed only in the physiological model, whereas 27.0% of blood remained in the nonphysiological model. This multiscale heart simulator provided detailed information on the cardiac mechanics and flow dynamics and could be a useful tool in cardiac physiology.
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