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Tao J, Duan F, Long J, Meng Q, Zhang B, Zhu Z, Wang H. The Role of the Submitral Apparatus in Hypertrophic Obstructive Cardiomyopathy. J Am Soc Echocardiogr 2023; 36:133-145. [PMID: 36191671 DOI: 10.1016/j.echo.2022.09.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 07/14/2022] [Accepted: 09/25/2022] [Indexed: 02/06/2023]
Abstract
Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiovascular disease, is characterized by unexplained hypertrophy of any myocardial segment, and has a prevalence of 0.2% to 0.5% among the general population. As one of the phenotypes of hypertrophic cardiomyopathy, left ventricular outflow tract obstruction (LVOTO) is associated with high morbidity and mortality, including cardiac death. The integration of various factors, including septal hypertrophy, malformation of the mitral valve apparatus, and an anomalous mitral subvalvular apparatus, may contribute to the occurrence of LVOTO. Previous studies have thoroughly discussed the role of the mitral valve in the mechanisms of systolic anterior motion and LVOTO. Recent studies have shown the importance of determining the potential mechanism of the submitral apparatus in inducing systolic anterior motion and LVOTO. The authors review recent advances in knowledge regarding the submitral apparatus of patients with hypertrophic cardiomyopathy.
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Affiliation(s)
- Jia Tao
- Department of Echocardiography, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Fujian Duan
- Department of Echocardiography, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; Department of Anesthesiology, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jili Long
- Department of Echocardiography, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Qinglong Meng
- Department of Echocardiography, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Bing Zhang
- Department of Echocardiography, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Zhenhui Zhu
- Department of Echocardiography, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Hao Wang
- Department of Echocardiography, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
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2
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Brunel L, Williams ZA, Yastrebov K, Robinson BM, Wise IK, Paterson HS, Bannon PG. Splitting the anterior mitral leaflet impairs left ventricular function in an ovine model. EUROPEAN JOURNAL OF CARDIO-THORACIC SURGERY : OFFICIAL JOURNAL OF THE EUROPEAN ASSOCIATION FOR CARDIO-THORACIC SURGERY 2022; 63:6849520. [PMID: 36440952 DOI: 10.1093/ejcts/ezac539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 11/01/2022] [Indexed: 11/30/2022]
Abstract
OBJECTIVES During mitral valve replacement, the anterior mitral leaflet is usually resected or modified. Anterior leaflet splitting seems the least disruptive modification. Reattachment of the modified leaflet to the annulus reduces the annulopapillary distance. The goal of this study was to quantify the acute effects on left ventricular function of splitting the anterior mitral leaflet and shortening the annulopapillary distance. METHODS In 6 adult sheep, a wire was placed around the anterior leaflet and exteriorized through the left ventricular wall to enable splitting the leaflet in the beating heart. Releasable snares to reduce annulopapillary distance were likewise positioned and exteriorized. A mechanical mitral prosthesis was inserted to prevent mitral incompetence during external manipulations of the native valve. Instantaneous changes in left ventricular function were recorded before and after shortening the annulopapillary distance, then before and after splitting the anterior leaflet. RESULTS After splitting the anterior leaflet, preload recruitable stroke work, stroke work, stroke volume, cardiac output, left ventricular end systolic pressure and mean pressure were significantly decreased by 26%, 23%, 12%, 9%, 15% and 11%, respectively. Shortening the annulopapillary distance was associated with significant decreases in the end systolic pressure volume relationship, preload recruitable stroke work, stroke work and left ventricular end systolic pressure by 67%, 33%, 15% and 13%, respectively. Shortening the annulopapillary distance after splitting the leaflet had no significant effect. CONCLUSIONS Splitting the anterior mitral leaflet acutely impaired left ventricular contractility and haemodynamics in an ovine model. Shortening the annulopapillary distance after leaflet splitting did not further impair left ventricular function.
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Affiliation(s)
| | - Zoe A Williams
- DVC Research Portfolio, The University of Sydney, NSW, Australia
| | - Konstantin Yastrebov
- Prince of Wales Medical School, Faculty of Medicine and Health, The University of New South Wales, NSW, Australia
| | - Benjamin M Robinson
- Institute of Academic Surgery and Baird Institute for Applied Heart and Lung Surgery, Camperdown, NSW, Australia
| | - Innes K Wise
- Department of Laboratory Animal Services, The University of Sydney, NSW, Australia
| | - Hugh S Paterson
- Central Clinical School-Surgery, Faculty of Medicine and Health, The University of Sydney, NSW, Australia
| | - Paul G Bannon
- Institute of Academic Surgery and Baird Institute for Applied Heart and Lung Surgery, Camperdown, NSW, Australia.,Central Clinical School-Surgery, Faculty of Medicine and Health, The University of Sydney, NSW, Australia
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3
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Calafiore AM, Prapas S, Totaro A, Guarracini S, Cargoni M, Katsavrias K, Fattouch K, Di Mauro M. Cutting the second order chords during mitral valve repair. J Card Surg 2022; 37:4072-4078. [PMID: 36378871 DOI: 10.1111/jocs.17194] [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: 07/04/2022] [Revised: 08/15/2022] [Accepted: 09/04/2022] [Indexed: 11/16/2022]
Abstract
The chordae tendinae connect the papillary muscles (PMs) to the mitral valve. While the first-order chordae serve to secure the leaflets to maintain valve closure and prevent mitral valve prolapse, the second-order chordae are believed to play a role in maintaining normal left ventricle size and geometry. The PMs, from where the chordae tendinae originate, function as shock absorbers that compensate for the geometric changes of the left ventricular wall. The second-order chordae connect the PMs to both trigons under tension. The tension distributed towards the second-order chordae has been demonstrate to be more than threefold that in their first-order counterpart. Cutting the second-order chordae puts all the tension on the first-order chordae, which are then closer to their rupture point. However, it has been experimentally demonstrated that the tension at which the first-order chordae break is 6.8 newtons (N), by far higher than the maximal tension reached, that is 0.4 N. Even if the clinical reports have been favorable, the importance of cutting the second-order chordae to recover curvature of the anterior leaflet and increase the coaptation length between the mitral valve leaflets has been slowly absorbed by the surgical world. Nevertheless, there are progressive demonstrations that chordal tethering affects the anterior leaflet not only in secondary, but also in primary mitral regurgitation, having a not negligible role in the long-term outcome of mitral repair.
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Affiliation(s)
| | - Sotirios Prapas
- Division of Cardiac Surgery A, Henry Dunant Hospital, Athens, Greece
| | - Antonio Totaro
- Department of Cardiovascular Diseases, Gemelli Molise, Campobasso, Italy
| | | | - Marco Cargoni
- Department of Surgical, Oncologic and Stomatological Disciplines, GVM Care & Research, Maria Eleonora Hospital, University of Palermo, Palermo, Italy
| | - Kostas Katsavrias
- Division of Cardiac Surgery A, Henry Dunant Hospital, Athens, Greece
| | - Khalil Fattouch
- Department of Cardiac Anesthesia, Mazzini Hospital, Teramo, Italy
| | - Michele Di Mauro
- Departmente of Cardio-Thoracic and Vascular Surgery, Heart and Vascular Center, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center (MUMC), Maastricht, The Netherlands
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4
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Guigui SA, Torres C, Escolar E, Mihos CG. Systolic anterior motion of the mitral valve in hypertrophic cardiomyopathy: a narrative review. J Thorac Dis 2022; 14:2309-2325. [PMID: 35813751 PMCID: PMC9264047 DOI: 10.21037/jtd-22-182] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 04/15/2022] [Indexed: 11/06/2022]
Abstract
Background and Objective The prevalence of hypertrophic cardiomyopathy (HCM) is estimated to be 1 in 200 to 500 individuals, with systolic anterior motion (SAM) of the mitral valve (MV) and left ventricular outflow tract (LVOT) obstruction present in 60% to 70%. In this narrative review, we aim to elucidate the pathophysiology of SAM-septal contact and LVOT obstruction in HCM by presenting a detailed review on the anatomy of the MV apparatus in HCM, examining the various existing theories pertaining to the SAM phenomenon as supported by cardiac imaging, and providing a critical assessment of management strategies for SAM in HCM. Methods A literature review was performed using PubMed, EMBASE, Ovid, and the Cochrane Library, of all scientific articles published through December 2021. A focus was placed on descriptive studies, reports correlating echocardiographic findings with pathologic diagnosis, and outcomes studies. Key Content and Findings The pathophysiology of SAM involves the complex interplay between HCM morphology, MV apparatus anatomic abnormalities, and labile hemodynamic derangements. Echocardiography and cardiac magnetic resonance (CMR) vector flow mapping have identified drag forces, as opposed to the "Venturi effect", as the main hydraulic forces responsible for SAM. The degree of mitral regurgitation with SAM is variable, and its severity is correlated with degree of LVOT obstruction and outcomes. First line therapy for the amelioration of SAM and LVOT obstruction is medical therapy with beta-blockers, non-dihydropyridine calcium-channel blockers, and disopyramide, in conjunction with lifestyle modifications. In refractory cases septal reduction therapy is performed, which may be combined with a 'resect-plicate-release' procedure, anterior mitral leaflet extension, surgical edge-to-edge MV repair, anterior mitral leaflet retention plasty, or secondary chordal cutting. Conclusions Recent scientific advances in the field of HCM have allowed for a maturation of our understanding of the SAM phenomenon. Cardiac imaging plays a critical role in its diagnosis, treatment, and surveillance, and in our ability to apply the appropriate therapeutic regimens. The increasing prevalence of HCM places an emphasis on continued basic and clinical research to further improve outcomes for this challenging population.
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Affiliation(s)
- Sarah A Guigui
- Echocardiography Laboratory, Columbia University Division of Cardiology, Mount Sinai Heart Institute, Miami Beach, FL, USA.,Columbia University Division of Cardiology, Mount Sinai Heart Institute, Miami Beach, FL, USA
| | - Christian Torres
- Columbia University Division of Cardiology, Mount Sinai Heart Institute, Miami Beach, FL, USA
| | - Esteban Escolar
- Columbia University Division of Cardiology, Mount Sinai Heart Institute, Miami Beach, FL, USA.,Coronary Care Unit, Columbia University Division of Cardiology, Mount Sinai Heart Institute, Miami Beach, FL, USA
| | - Christos G Mihos
- Echocardiography Laboratory, Columbia University Division of Cardiology, Mount Sinai Heart Institute, Miami Beach, FL, USA.,Columbia University Division of Cardiology, Mount Sinai Heart Institute, Miami Beach, FL, USA
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5
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Pausch J, Girdauskas E, Conradi L, Reichenspurner H. Secondary mitral regurgitation repair techniques and outcomes: Subannular repair techniques in secondary mitral regurgitation type IIIb. JTCVS Tech 2022; 10:92-97. [PMID: 34977710 PMCID: PMC8691802 DOI: 10.1016/j.xjtc.2021.09.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 09/02/2021] [Indexed: 11/30/2022] Open
Affiliation(s)
- Jonas Pausch
- Department of Cardiovascular Surgery University Heart & Vascular Center Hamburg, Hamburg, Germany
| | - Evaldas Girdauskas
- Department of Cardiothoracic Surgery, University Hospital Augsburg, Augsburg, Germany
| | - Lenard Conradi
- Department of Cardiovascular Surgery University Heart & Vascular Center Hamburg, Hamburg, Germany
| | - Hermann Reichenspurner
- Department of Cardiovascular Surgery University Heart & Vascular Center Hamburg, Hamburg, Germany
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Varma PK, Krishna N, Jose R, Gopal K, Ahamed H. "Do alternative approaches work in surgical septal myectomy?". Asian Cardiovasc Thorac Ann 2021; 30:84-91. [PMID: 34120476 DOI: 10.1177/02184923211025396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Trans-aortic septal myectomy is the gold standard for septal reduction therapy. This technique has low peri-procedural mortality and excellent long-term survival. Moreover, it relieves the heart failure symptoms and improves the quality of life. Secondary chordal cutting along with septal myectomy has shown to improve the outcome but can potentially cause deterioration of left ventricular function. In patients with relatively thin inter-ventricular septum, abnormalities of mitral valve apparatus may be the main reason for systolic anterior motion and left ventricular outflow tract obstruction. These patients may require additional procedures on the mitral valve to shift the coaptation plane away from outflow tract. Mitral valve replacement should be performed only in patients with intrinsic mitral valve abnormalities that are not suitable for repair and its routine use along with limited septal myectomy should be discouraged. Minimal access surgery although attractive in concept requires more robust data before universal application.
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Affiliation(s)
- Praveen Kerala Varma
- Center for Hypertrophic Cardiomyopathy, Amrita Institute of Medical sciences, Amrita Viswa Vidyapeetham (Amrita University), Kochi, India
| | - Neethu Krishna
- Center for Hypertrophic Cardiomyopathy, Amrita Institute of Medical sciences, Amrita Viswa Vidyapeetham (Amrita University), Kochi, India
| | - Rajesh Jose
- Center for Hypertrophic Cardiomyopathy, Amrita Institute of Medical sciences, Amrita Viswa Vidyapeetham (Amrita University), Kochi, India
| | - Kirun Gopal
- Center for Hypertrophic Cardiomyopathy, Amrita Institute of Medical sciences, Amrita Viswa Vidyapeetham (Amrita University), Kochi, India
| | - Hisham Ahamed
- Center for Hypertrophic Cardiomyopathy, Amrita Institute of Medical sciences, Amrita Viswa Vidyapeetham (Amrita University), Kochi, India
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Ji Q, Wang YL, Yang Y, Lai H, Ding WJ, Xia LM, Wang CS. Mini-invasive surgical instruments in transaortic myectomy for hypertrophic obstructive cardiomyopathy: a single-center experience with 168 cases. J Cardiothorac Surg 2021; 16:25. [PMID: 33731165 PMCID: PMC7968270 DOI: 10.1186/s13019-021-01403-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 03/08/2021] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Although septal myectomy is a standard strategy for managing patients with hypertrophic obstructive cardiomyopathy (HOCM) and drug-refractory symptoms, so far, only a few experienced myectomy centers exist globally. Mainly, this can be explained by the many technical challenges presented by myectomy. From our clinical experience, applying the mini-invasive surgical instruments during myectomy potentially reduces the technical difficulty. This study reports the preliminary experience regarding transaortic septal myectomy using mini-invasive surgical instruments for managing patients with HOCM and drug-refractory symptoms; also, we evaluate the early results following myectomy. METHODS Between March 2016 and March 2019, consecutive HOCM patients who underwent isolated transaortic septal myectomy using the mini-invasive surgical instruments were enrolled in this analysis. Intraoperative, in-hospital and follow-up results were analyzed. RESULTS We included 168 eligible patients (83 males, mean 56.8 ± 12.3 years). The midventricular obstruction was recorded in 7 (4.2%) patients. All patients underwent transaortic septal myectomy with a mean aortic cross-clamping time of 36.0 ± 8.1 min. During myectomy, 9 (5.4%) patients received repeat aortic cross-clamping. Surgical mortality was 0.6%. Notably, 5 (3.0%) patients developed complete atrioventricular block, they needed permanent pacemaker implantation. The median follow-up time was 6 months; however, no follow-up deaths occurred with a significant improvement in New York Heart Association functional status. We reported a sharp decrease in the maximum gradients from the preoperative value (11.6 ± 7.4 mmHg vs. 94.4 ± 22.6 mmHg, p < 0.001). The median degree of mitral regurgitation fell to 1.0 (vs. 3.0 preoperatively, p < 0.001) with a significant reduction in the proportion of moderate or more regurgitation (1.2% vs. 57.7%, p < 0.001). CONCLUSIONS Mini-invasive surgical instruments may be beneficial in reducing the technical challenges of transaortic septal myectomy procedure. Of note, transaortic septal myectomy using the mini-invasive surgical instruments may present with favorable results.
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Affiliation(s)
- Qiang Ji
- Department of Cardiovascular Surgery of Zhongshan Hospital Fudan University, 180 Fenglin Rd, Shanghai, 200032, China
| | - Yu Lin Wang
- Department of Cardiovascular Surgery of Zhongshan Hospital Fudan University, 180 Fenglin Rd, Shanghai, 200032, China
| | - Ye Yang
- Department of Cardiovascular Surgery of Zhongshan Hospital Fudan University, 180 Fenglin Rd, Shanghai, 200032, China
| | - Hao Lai
- Department of Cardiovascular Surgery of Zhongshan Hospital Fudan University, 180 Fenglin Rd, Shanghai, 200032, China
| | - Wen Jun Ding
- Department of Cardiovascular Surgery of Zhongshan Hospital Fudan University, 180 Fenglin Rd, Shanghai, 200032, China
| | - Li Min Xia
- Department of Cardiovascular Surgery of Zhongshan Hospital Fudan University, 180 Fenglin Rd, Shanghai, 200032, China.
- Department of Cardiovascular Surgery of Xiamen Branch of Zhongshan Hospital Fudan University, 668 Jinhu Road, Huli District, Xiamen, 510530, China.
| | - Chun Sheng Wang
- Shanghai Municipal Institute for Cardiovascular Diseases, 1609 Xietu Road, Shanghai, 200032, China.
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Ram E, Schwammenthal E, Kuperstein R, Jamal T, Nahum E, Sternik L, Raanani E. Secondary chordal resection with septal myectomy for treatment of symptomatic obstructive hypertrophic cardiomyopathy. Eur J Cardiothorac Surg 2021; 60:699-707. [PMID: 33693690 DOI: 10.1093/ejcts/ezab116] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 01/09/2021] [Accepted: 01/31/2021] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES Left ventricular outflow tract obstruction causes symptoms of heart failure in most patients with hypertrophic cardiomyopathy. Resection of the secondary mitral valve (MV) chordae has recently been shown to move the MV apparatus posteriorly, thereby eradicating the outflow gradient. The aim of this study was to evaluate whether secondary chordal resection concomitant to septal myectomy improves outcomes. METHODS Between 2005 and 2020, a total of 165 patients underwent septal myectomy without MV repair or replacement in our Medical Center. Secondary MV chordal resection was performed in 60 patients, and their outcomes were compared with those of the remaining 105 patients who did not undergo chordal resection (controls). Mean age was 61 ± 13 and 58 ± 16 years, respectively (P = 0.205). RESULTS There were no in-hospital deaths throughout the entire cohort. Of those patients who underwent secondary chordal resection, New York Heart Association functional class decreased from 3 (interquartile range 2-3) preoperatively to 1 (interquartile range 1-2) postoperatively (P < 0.001), and resting outflow gradient decreased from 91 ± 39 mmHg to 13 ± 8 mmHg (86% change, P < 0.001). Compared with controls, patients who underwent secondary chordal resection had a significant lower resting outflow gradient at follow-up (14 ± 7 mmHg vs 21 ± 15 mmHg, P = 0.002). The rate of moderate or more than moderate mitral regurgitation at 5 years was 2% in the secondary chordal resection group and 5% in the controls (hazard ratio 1.05, confidence interval 0.11-10.32; P = 0.965). CONCLUSIONS In this observational study, we report that secondary chordal resection concomitant to septal myectomy for left ventricular outflow tract obstruction is safe, relieves heart failure symptoms and reduces left ventricular outflow tract gradient in appropriately selected patients.
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Affiliation(s)
- Eilon Ram
- Department of Cardiac Surgery, Leviev Cardiothoracic and Vascular Center, Sheba Medical Center, Tel Hashomer, Israel.,Affiliated to the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ehud Schwammenthal
- Affiliated to the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.,Department of Cardiology, Leviev Cardiothoracic and Vascular Center, Sheba Medical Center, Tel Hashomer, Israel
| | - Rafael Kuperstein
- Affiliated to the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.,Department of Cardiology, Leviev Cardiothoracic and Vascular Center, Sheba Medical Center, Tel Hashomer, Israel
| | - Tamer Jamal
- Department of Cardiac Surgery, Leviev Cardiothoracic and Vascular Center, Sheba Medical Center, Tel Hashomer, Israel.,Affiliated to the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Eyal Nahum
- Department of Cardiac Surgery, Leviev Cardiothoracic and Vascular Center, Sheba Medical Center, Tel Hashomer, Israel.,Affiliated to the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Leonid Sternik
- Department of Cardiac Surgery, Leviev Cardiothoracic and Vascular Center, Sheba Medical Center, Tel Hashomer, Israel.,Affiliated to the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ehud Raanani
- Department of Cardiac Surgery, Leviev Cardiothoracic and Vascular Center, Sheba Medical Center, Tel Hashomer, Israel.,Affiliated to the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
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Corporan D, Onohara D, Amedi A, Saadeh M, Guyton RA, Kumar S, Padala M. Hemodynamic and transcriptomic studies suggest early left ventricular dysfunction in a preclinical model of severe mitral regurgitation. J Thorac Cardiovasc Surg 2021; 161:961-976.e22. [PMID: 33277035 PMCID: PMC7889661 DOI: 10.1016/j.jtcvs.2020.08.119] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 08/06/2020] [Accepted: 08/24/2020] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Primary mitral regurgitation is a valvular lesion in which the left ventricular ejection fraction remains preserved for long periods, delaying a clinical trigger for mitral valve intervention. In this study, we sought to investigate whether adverse left ventricular remodeling occurs before a significant fall in ejection fraction and characterize these changes. METHODS Sixty-five rats were induced with severe mitral regurgitation by puncturing the mitral valve leaflet with a 23-G needle using ultrasound guidance. Rats underwent longitudinal cardiac echocardiography at biweekly intervals and hearts explanted at 2 weeks (n = 15), 10 weeks (n = 15), 20 weeks (n = 15), and 40 weeks (n = 15). Sixty age- and weight-matched healthy rats were used as controls. Unbiased RNA-sequencing was performed at each terminal point. RESULTS Regurgitant fraction was 40.99 ± 9.40%, with pulmonary flow reversal in the experimental group, and none in the control group. Significant fall in ejection fraction occurred at 14 weeks after mitral regurgitation induction. However, before 14 weeks, end-diastolic volume increased by 93.69 ± 52.38% (P < .0001 compared with baseline), end-systolic volume increased by 118.33 ± 47.54% (P < .0001 compared with baseline), and several load-independent pump function indices were reduced. Transcriptomic data at 2 and 10 weeks before fall in ejection fraction indicated up-regulation of myocyte remodeling and oxidative stress pathways, whereas those at 20 and 40 weeks indicated extracellular matrix remodeling. CONCLUSIONS In this rodent model of mitral regurgitation, left ventricular ejection fraction was preserved for a long duration, yet rapid and severe left ventricular dilatation, and biological remodeling occurred before a clinically significant fall in ejection fraction.
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Affiliation(s)
- Daniella Corporan
- Structural Heart Research and Innovation Laboratory, Carlyle Fraser Heart Center at Emory University Hospital Midtown, Atlanta, Ga
| | - Daisuke Onohara
- Structural Heart Research and Innovation Laboratory, Carlyle Fraser Heart Center at Emory University Hospital Midtown, Atlanta, Ga
| | - Alan Amedi
- Structural Heart Research and Innovation Laboratory, Carlyle Fraser Heart Center at Emory University Hospital Midtown, Atlanta, Ga
| | - Maher Saadeh
- Structural Heart Research and Innovation Laboratory, Carlyle Fraser Heart Center at Emory University Hospital Midtown, Atlanta, Ga
| | - Robert A Guyton
- Structural Heart Research and Innovation Laboratory, Carlyle Fraser Heart Center at Emory University Hospital Midtown, Atlanta, Ga; Division of Cardiothoracic Surgery, Department of Surgery, Emory University School of Medicine, Atlanta, Ga
| | - Sandeep Kumar
- Department of Biomedical Engineering, Emory University School of Medicine, Atlanta, Ga
| | - Muralidhar Padala
- Structural Heart Research and Innovation Laboratory, Carlyle Fraser Heart Center at Emory University Hospital Midtown, Atlanta, Ga; Division of Cardiothoracic Surgery, Department of Surgery, Emory University School of Medicine, Atlanta, Ga.
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10
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Calafiore AM, Totaro A, De Amicis V, Pelini P, Pinna G, Testa N, Alfonso JJ, Mazzei V, Sacra C, Gaudino M, Di Mauro M. Surgical mitral plasticity for chronic ischemic mitral regurgitation. J Card Surg 2020; 35:772-778. [PMID: 32126160 DOI: 10.1111/jocs.14487] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND AND AIM OF THE STUDY The outcome of mitral valve (MV) repair for chronic ischemic mitral regurgitation (IMR) is suboptimal, due to the high recurrence rate of moderate or severe mitral regurgitation (MR) during follow-up. The MV adapts to new MR increasing its area to cover the enlarged annular area (mitral plasticity). As this process is often incomplete, we aimed to evaluate if augmenting the anterior leaflet (AL) and cutting the second-order chords (CC) together with restrictive mitral annuloplasty, a strategy we call "surgical mitral plasticity," could improve the midterm results of MV repair for IMR. MATERIALS AND METHODS From November 2017 to October 2019, 22 patients with chronic IMR underwent surgical mitral plasticity. Mean age was 73 ± 7 years and six were female. Mean ejection fraction was 32% ± 11%, IMR grade was moderate in 10 and severe in 12. Mean clinical and echocardiographic follow-up was 12 ± 6 months. RESULTS There was no early death, and one patient died 6 months after surgery. Ejection fraction improved from 32% ± 15% to 40% ± 6% (P = .031). IMR was absent or mild in all patients, and none showed recurrent moderate or more IMR. Tenting area decreased significantly from 2.5 ± 0.5 to 0.5 ± 0.3 cm² and coaptation length increased from 1.9 ± 0.7 to 7.8 ± 1.6 mm. All patients were in New York Heart Association class I or II. CONCLUSIONS Mitral plasticity, if uncomplete, is ineffective in preventing IMR to become significant. Surgical mitral plasticity, by completing incomplete process of MV adaptation, has a strong rationale, which however needs to be validated with longer follow-up.
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Affiliation(s)
| | - Antonio Totaro
- Department of Cardiovascular Diseases, Gemelli Molise, Campobasso, Italy
| | | | - Piero Pelini
- Division of Cardiac Surgery, D'Annunzio University, Chieti, Italy
| | - Giovanni Pinna
- Division of Cardiac Surgery, Federico II University, Naples, Italy
| | - Nicola Testa
- Department of Cardiovascular Diseases, Gemelli Molise, Campobasso, Italy
| | - Juan J Alfonso
- Department of Research, Prince Sultan Cardiac Center, Riyadh, Saudi Arabia
| | - Valerio Mazzei
- Department of Cardiovascular Diseases, Gemelli Molise, Campobasso, Italy
| | - Cosimo Sacra
- Department of Cardiovascular Diseases, Gemelli Molise, Campobasso, Italy
| | - Mario Gaudino
- Department of Cardiothoracic Surgery, Weill Cornell Medicine, New York, New York
| | - Michele Di Mauro
- Division of Cardiac Surgery, D'Annunzio University, Chieti, Italy
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11
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Maggiore P, Anastasius M, Huang AL, Blanke P, Leipsic J. Transcatheter Mitral Valve Repair and Replacement: Current Evidence for Intervention and the Role of CT in Preprocedural Planning-A Review for Radiologists and Cardiologists Alike. Radiol Cardiothorac Imaging 2020; 2:e190106. [PMID: 33778537 DOI: 10.1148/ryct.2020190106] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 09/05/2019] [Accepted: 09/26/2019] [Indexed: 01/21/2023]
Abstract
The mitral valve is a complex structure with a three-dimensional saddle shape annulus. Mitral regurgitation occurs from leaflet coaptation failure that is either primary (a problem with the leaflets) or secondary (chamber dilatation in the setting of cardiomyopathy). There has been an increase in focus on transcatheter mitral valve interventions, for both mitral repair and replacement. These technologies have rapidly developed to provide treatment for a substantial number of patients with severe symptomatic mitral regurgitation who are at too high of a risk to undergo open heart surgery. CT assessment of the mitral valve has developed with equal rapidity, with regard to preprocedural planning for transcatheter therapies. This review will provide an overview of mitral valve anatomy, an update on the current transcatheter repair and replacement therapies, as well as a focused overview of the role of multislice CT in mitral assessment prior to intervention. © RSNA, 2020.
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Affiliation(s)
- Paul Maggiore
- Centre for Heart Valve Innovation, St Paul's Hospital, University of British Columbia, 1081 Burrard St, Vancouver, BC, Canada V6Z 1Y6
| | - Malcolm Anastasius
- Centre for Heart Valve Innovation, St Paul's Hospital, University of British Columbia, 1081 Burrard St, Vancouver, BC, Canada V6Z 1Y6
| | - Alex L Huang
- Centre for Heart Valve Innovation, St Paul's Hospital, University of British Columbia, 1081 Burrard St, Vancouver, BC, Canada V6Z 1Y6
| | - Philipp Blanke
- Centre for Heart Valve Innovation, St Paul's Hospital, University of British Columbia, 1081 Burrard St, Vancouver, BC, Canada V6Z 1Y6
| | - Jonathon Leipsic
- Centre for Heart Valve Innovation, St Paul's Hospital, University of British Columbia, 1081 Burrard St, Vancouver, BC, Canada V6Z 1Y6
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12
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Athanasuleas CL, Stanley AWH, Buckberg GD. Mitral regurgitation: anatomy is destiny. Eur J Cardiothorac Surg 2018; 54:627-634. [PMID: 29718159 DOI: 10.1093/ejcts/ezy174] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 03/18/2018] [Indexed: 11/13/2022] Open
Abstract
Mitral regurgitation (MR) occurs when any of the valve and ventricular mitral apparatus components are disturbed. As MR progresses, left ventricular remodelling occurs, ultimately causing heart failure when the enlarging left ventricle (LV) loses its conical shape and becomes globular. Heart failure and lethal ventricular arrhythmias may develop if the left ventricular end-systolic volume index exceeds 55 ml/m2. These adverse changes persist despite satisfactory correction of the annular component of MR. Our goal was to describe this process and summarize evolving interventions that reduce the volume of the left ventricle and rebuild its elliptical shape. This 'valve/ventricle' approach addresses the spherical ventricular culprit and offsets the limits of treating MR by correcting only its annular component.
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Affiliation(s)
- Constantine L Athanasuleas
- Section of Cardiothoracic Surgery, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | | | - Gerald D Buckberg
- Department of Cardiothoracic Surgery, University of California Los Angeles, Los Angeles, CA, USA
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13
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Mihos CG, Xydas S, Yucel E, Capoulade R, Williams RF, Mawad M, Garcia G, Santana O. Mitral valve repair and subvalvular intervention for secondary mitral regurgitation: a systematic review and meta-analysis of randomized controlled and propensity matched studies. J Thorac Dis 2017; 9:S582-S594. [PMID: 28740711 DOI: 10.21037/jtd.2017.05.56] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Combining a ring annuloplasty (Ring) with a mitral subvalvular intervention (Ring + subvalvular) in patients with secondary mitral regurgitation (MR) may improve mitral valve (MV) repair durability. However, the outcomes of this strategy compared with a Ring only, have not been clearly defined. METHODS A systematic review and meta-analysis was performed utilizing randomized controlled and propensity matched studies which compared a Ring + subvalvular versus Ring MV repair for the treatment of secondary MR. Risk ratio (RR), weighted mean difference (MD), and the 95% confidence interval (CI) were calculated by the Mantel-Haenszel and inverse-variance methods, for clinical outcomes and echocardiographic measures of follow-up MR, left ventricular (LV) reverse remodeling, and MV apparatus geometry. RESULTS Five studies were identified, with a total of 397 patients. Baseline characteristics were similar between groups, and all patients had moderate to severe secondary MR, with the vast majority in the setting of ischemic cardiomyopathy. A Ring + subvalvular repair consisted of papillary muscle approximation (n=2), papillary muscle relocation (n=2), or secondary chordal cutting (n=1). Follow-up ranged from 10.1 (mean range =0.25-42) to 69 [interquartile range (IQR) =23-82] months. When compared with Ring only at last follow-up, a Ring + subvalvular MV repair was associated with: (I) a smaller MR grade (MD =-0.44, 95% CI -0.69 to -0.19; P=0.0005); (II) a reduced risk of moderate or greater recurrent MR (RR =0.43, 95% CI, 0.27-0.66; P=0.0002); (III) a smaller mean LV end-diastolic diameter (MD =-3.56 mm, 95% CI -5.40 to -1.73; P=0.0001) and a greater ejection fraction (MD =2.64%, 95% CI, 0.13-5.15; P=0.04); and, (IV) an improved MV apparatus geometry. There were no differences in operative mortality, post-operative morbidity, or follow-up survival between surgical approaches. CONCLUSIONS When compared with Ring only, a Ring + subvalvular MV repair is associated with greater LV reverse remodeling and systolic function, less recurrence of moderate or greater MR, and an improved geometry of the MV apparatus at short and mid-term follow-up.
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Affiliation(s)
- Christos G Mihos
- Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Steve Xydas
- Columbia University Division of Cardiac Surgery, Mount Sinai Heart Institute, Miami Beach, FL, USA
| | - Evin Yucel
- Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Romain Capoulade
- Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Roy F Williams
- Columbia University Division of Cardiac Surgery, Mount Sinai Heart Institute, Miami Beach, FL, USA
| | - Maurice Mawad
- Columbia University Division of Cardiac Surgery, Mount Sinai Heart Institute, Miami Beach, FL, USA
| | - Guillermo Garcia
- Department of Anesthesia, Mount Sinai Medical Center, Miami Beach, FL, USA
| | - Orlando Santana
- Columbia University Division of Cardiology, Mount Sinai Heart Institute, Miami Beach, FL, USA
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Roshanali F, Naderan M, Shoar S, Vedadian A, Sandoughdaran S, Shoar N, Mandegar MH. Length of second-order chordae as a predictor of systolic anterior motion of the mitral valve. Interact Cardiovasc Thorac Surg 2016; 23:280-5. [PMID: 27099267 DOI: 10.1093/icvts/ivw106] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Accepted: 03/16/2016] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES The aim of the present study was to ascertain whether the length of anterior mitral leaflet second-order chordae (SOC) could be considered as a predictor of the incidence of post-repair systolic anterior motion (SAM) and left ventricular outflow tract obstruction (LVOTO) in patients with myxomatous mitral valve disease. METHODS With the implementation of preoperative transoesophageal echocardiography (TEE), the length of anterior mitral leaflet SOC, anterior leaflet (AL) and posterior leaflet (PL) as well as the distance from the coaptation point to the septum (C-S distance) before and after mitral valve repair (MVR) surgery were measured in 190 patients, comprising 12 who developed SAM and 178 who did not. RESULTS The results revealed that, in patients who developed SAM, SOC were significantly higher (2.76 ± 0.15 vs 1.83 ± 0.32 mm, P < 0.001) and the C-S distance was significantly lower (2.18 ± 0.36 vs 2.91 ± 0.36 mm, P < 0.001) in comparison to the obtained results for those who did not develop SAM. SOC and the C-S distance were independent risk factors of developing SAM and had the largest area under the receiver operating characteristic (ROC) curve (P < 0.001). With application of a cut-off ROC curve analysis, the cut-offs selected for the two variables of C-S distance and SOC were 2.5 and 2.6, respectively. Sensitivity and specificity of SAM development were 100% [95% confidence interval (CI): 73.5-100] and 87.1% (95% CI: 81.0-91.4) for SOC ≥2.6 and 83.3% (95% CI: 51.6-97.9) and 73.6% (95% CI: 66.4-79.9) for the C-S distance ≤2.5. CONCLUSIONS The two variables of the second-order chordae and the distance from the coaptation point to the septum were associated with an increased risk of the post-repair systolic anterior motion after mitral valve repair.
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Affiliation(s)
| | - Mohammad Naderan
- Department of Surgery, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Saeed Shoar
- Department of Cardiac Surgery, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Ali Vedadian
- Department of Cardiology, Day General Hospital, Tehran, Iran
| | - Saleh Sandoughdaran
- Department of Cardiac Surgery, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Nasrin Shoar
- Department of Cardiology, Day General Hospital, Tehran, Iran
| | - Mohammad Hossein Mandegar
- Department of Cardiac Surgery, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
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Natarajan N, Patel P, Bartel T, Kapadia S, Navia J, Stewart W, Tuzcu EM, Schoenhagen P. Peri-procedural imaging for transcatheter mitral valve replacement. Cardiovasc Diagn Ther 2016; 6:144-59. [PMID: 27054104 DOI: 10.21037/cdt.2016.02.04] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Mitral regurgitation (MR) has a high prevalence in older patient populations of industrialized nations. Common etiologies are structural, degenerative MR and functional MR secondary to myocardial remodeling. Because of co-morbidities and associated high surgical risk, open surgical mitral repair/replacement is deferred in a significant percentage of patients. For these patients transcatheter repair/replacement are emerging as treatment options. Because of the lack of direct visualization, pre- and intra-procedural imaging is critical for these procedures. In this review, we summarize mitral valve anatomy, trans-catheter mitral valve replacement (TMVR) options, and imaging in the context of TMVR.
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Affiliation(s)
- Navin Natarajan
- 1 Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA ; 2 Department of Cardiovascular Medicine, 3 Department of Cardiothoracic Surgery, Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH 44106, USA ; 4 Imaging Institute, Cleveland Clinic, Cleveland, OH 44106, USA
| | - Parag Patel
- 1 Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA ; 2 Department of Cardiovascular Medicine, 3 Department of Cardiothoracic Surgery, Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH 44106, USA ; 4 Imaging Institute, Cleveland Clinic, Cleveland, OH 44106, USA
| | - Thomas Bartel
- 1 Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA ; 2 Department of Cardiovascular Medicine, 3 Department of Cardiothoracic Surgery, Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH 44106, USA ; 4 Imaging Institute, Cleveland Clinic, Cleveland, OH 44106, USA
| | - Samir Kapadia
- 1 Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA ; 2 Department of Cardiovascular Medicine, 3 Department of Cardiothoracic Surgery, Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH 44106, USA ; 4 Imaging Institute, Cleveland Clinic, Cleveland, OH 44106, USA
| | - Jose Navia
- 1 Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA ; 2 Department of Cardiovascular Medicine, 3 Department of Cardiothoracic Surgery, Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH 44106, USA ; 4 Imaging Institute, Cleveland Clinic, Cleveland, OH 44106, USA
| | - William Stewart
- 1 Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA ; 2 Department of Cardiovascular Medicine, 3 Department of Cardiothoracic Surgery, Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH 44106, USA ; 4 Imaging Institute, Cleveland Clinic, Cleveland, OH 44106, USA
| | - E Murat Tuzcu
- 1 Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA ; 2 Department of Cardiovascular Medicine, 3 Department of Cardiothoracic Surgery, Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH 44106, USA ; 4 Imaging Institute, Cleveland Clinic, Cleveland, OH 44106, USA
| | - Paul Schoenhagen
- 1 Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA ; 2 Department of Cardiovascular Medicine, 3 Department of Cardiothoracic Surgery, Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH 44106, USA ; 4 Imaging Institute, Cleveland Clinic, Cleveland, OH 44106, USA
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16
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Bothe W, Schubert H, Diab M, Faerber G, Bettag C, Jiang X, Fischer MS, Denzler J, Doenst T. Fully automated tracking of cardiac structures using radiopaque markers and high-frequency videofluoroscopy in an in vivo ovine model: from three-dimensional marker coordinates to quantitative analyses. SPRINGERPLUS 2016; 5:220. [PMID: 27026914 PMCID: PMC4771645 DOI: 10.1186/s40064-016-1868-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 02/16/2016] [Indexed: 11/10/2022]
Abstract
PURPOSE Recently, algorithms were developed to track radiopaque markers in the heart fully automated. However, the methodology did not allow to assign the exact anatomical location to each marker. In this case study we describe the steps from the generation of three-dimensional marker coordinates to quantitative data analyses in an in vivo ovine model. METHODS In one adult sheep, twenty silver balls were sutured to the right side of the heart: 10 to the tricuspid annulus, one to the anterior tricuspid leaflet and nine to the epicardial surface of the right ventricle. In addition, 13 cylindrical tantalum markers were implanted into the left ventricle. Data were acquired with a biplanar X-ray acquisition system (Neurostar R, Siemens AG, 500 Hz). Radiopaque marker coordinates were determined fully automated using novel tracking algorithms. RESULTS The anatomical marker locations were identified using a 3-dimensional model of a single frame containing all tracked markers. First, cylindrical markers were manually separated from spherical markers, thus allowing to distinguish right from left heart markers. The fast moving leaflet marker was identified by using video loops constructed of all recorded frames. Rotation of the 3-dimensional model allowed the identification of the precise anatomical position for each marker. Data sets were then analyzed quantitatively using customized software. CONCLUSIONS The method presented in this case study allowed quantitative data analyses of radiopaque cardiac markers that were tracked fully automated with high temporal resolution. However, marker identification still requires substantial manual work. Future improvements including the implication of marker identification algorithms and data analysis software could allow almost real-time quantitative analyses of distinct cardiac structures with high temporal and spatial resolution.
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Affiliation(s)
- Wolfgang Bothe
- Department of Cardiothoracic Surgery, University Hospital Jena, 07747 Jena, Germany ; Department of Cardiovascular Surgery, University Heart Center Freiburg - Bad Krozingen, Freiburg, Germany
| | - Harald Schubert
- Institute of Laboratory Animals Science, Friedrich-Schiller-University, Jena, Germany
| | - Mahmoud Diab
- Department of Cardiothoracic Surgery, University Hospital Jena, 07747 Jena, Germany
| | - Gloria Faerber
- Department of Cardiothoracic Surgery, University Hospital Jena, 07747 Jena, Germany
| | - Christoph Bettag
- Department of Cardiothoracic Surgery, University Hospital Jena, 07747 Jena, Germany
| | - Xiaoyan Jiang
- Computer Vision Group, Friedrich Schiller University, Jena, Germany
| | - Martin S Fischer
- Institute of Systematic Zoology and Evolutionary Biology, Friedrich Schiller University, Jena, Germany
| | - Joachim Denzler
- Computer Vision Group, Friedrich Schiller University, Jena, Germany
| | - Torsten Doenst
- Department of Cardiothoracic Surgery, University Hospital Jena, 07747 Jena, Germany
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17
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Tan TC, Hung JW. Standard transthoracic echocardiography and transesophageal echocardiography views of mitral pathology that every surgeon should know. Ann Cardiothorac Surg 2015; 4:449-60. [PMID: 26539350 DOI: 10.3978/j.issn.2225-319x.2015.03.05] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
The mitral valve is the most commonly diseased heart valve and the prevalence of mitral valve disease increases proportionally with age. Echocardiography is the primary diagnostic imaging modality used in the assessment of patients with mitral valve disease. It is a noninvasive method which provides accurate anatomic and functional information regarding the mitral valve and can identify the mechanism of mitral valve pathology. This is especially useful as it may guide surgical repair. This is increasingly relevant given the growing trend of patients undergoing mitral valve repair. Collaboration between cardiac surgeons and echocardiographers is critical in the evaluation of mitral valve disease and for identification of complex valvular lesions that require advanced surgical skill to repair. This article will provide an overview of transthoracic and transesophageal assessment of common mitral valve pathology that aims to aid surgical decision making.
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Affiliation(s)
- Timothy C Tan
- Cardiac Ultrasound Laboratory, Division of Cardiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Judy W Hung
- Cardiac Ultrasound Laboratory, Division of Cardiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
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18
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Ferrazzi P, Spirito P, Iacovoni A, Calabrese A, Migliorati K, Simon C, Pentiricci S, Poggio D, Grillo M, Amigoni P, Iascone M, Mortara A, Maron BJ, Senni M, Bruzzi P. Transaortic Chordal Cutting. J Am Coll Cardiol 2015; 66:1687-96. [DOI: 10.1016/j.jacc.2015.07.069] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 07/23/2015] [Accepted: 07/24/2015] [Indexed: 12/01/2022]
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Parannular Elliptical Posterior Resection: A Low-Impact Reparative Technique for Mitral Valve Prolapse. INNOVATIONS-TECHNOLOGY AND TECHNIQUES IN CARDIOTHORACIC AND VASCULAR SURGERY 2015; 10:252-7; discussion 257. [PMID: 26360980 DOI: 10.1097/imi.0000000000000181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Although effective, Carpentier technique for mitral regurgitation presents two "Achille's heel": the resection of the whole prolapsing section of posterior mitral leaflet (PML) including chordae tendinae and the annular distortion due to plication. An alternative technique of limited PML resection, which preserves mitral anatomy decreasing the impact on valve function, and 9-year outcome are presented. METHODS Since April 2005 till March 2014, of 205 patients affected by mitral prolapse scheduled for repair (mitral valve repair), 54 patients have been included in the study. The rationale of the new technique was to limit PML resection to achieve a fair reduction of the prolapsing scallop(s) height, to avoid leaflet and annular distortion, and to spare the coaptation surface and other substantial structures. According to the observation that the posterior smooth zone of PML is quite free from chordal insertions, an elliptical slice of tissue was resected from this area. Annuloplasty and neochordal insertion when indicated completed the procedure. RESULTS Up to 9 years of follow-up was 98% complete. One in-hospital death, two late noncardiac deaths, one redo operation due to endocarditis were reported. On late follow-up, 92% patients were on New York Heart Association class I. Late echocardiography showed stability of repair (regurgitation grade of ≤1 in 92% of patients). Nearly two third of valves preserved good PML mobility. CONCLUSIONS The parannular elliptical posterior leaflet resection, providing excellent stable midterm results, seems to be a safe alternative method for repair of PML prolapse. It avoids distortion and weakening of annulus and leaflet, and it allows restoring a proper coaptation surface and maintains a satisfactory PML motion.
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20
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Da Col U, Perticoni S, Ramoni E. Parannular Elliptical Posterior Resection: A Low-Impact Reparative Technique for Mitral Valve Prolapse. INNOVATIONS-TECHNOLOGY AND TECHNIQUES IN CARDIOTHORACIC AND VASCULAR SURGERY 2015. [DOI: 10.1177/155698451501000406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Uberto Da Col
- Department of Cardiac Surgery, S. Maria della Misericordia Hospital, Perugia, Italy
| | - Simone Perticoni
- Department of Cardiac Surgery, S. Maria della Misericordia Hospital, Perugia, Italy
| | - Enrico Ramoni
- Department of Cardiac Surgery, S. Maria della Misericordia Hospital, Perugia, Italy
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21
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Gunnal SA, Wabale RN, Farooqui MS. Morphological study of chordae tendinae in human cadaveric hearts. Heart Views 2015; 16:1-12. [PMID: 25838872 PMCID: PMC4379635 DOI: 10.4103/1995-705x.152994] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Objectives: The chordae tendinae (CT) are strong, fibrous connections between the valve leaflets and the papillary muscles. Dysfunction of the papillary muscles and chordae is frequent. Mitral valve replacement with preservation of CT and papillary muscles may preserve postoperative left ventricular function better than conventional mitral valve replacement in patients with chronic mitral regurgitation. Methods: The study was carried out on 116 human cadaveric hearts. The heart was opened through the atrioventricular valve to view the constituents of the complex. Origin, attachments, insertions, distribution, branching pattern and gross structure of CT were observed and studied in detail. Results: In the present study more than 21 terminologies of CT were defined by classifying it into six different types. Classification is done according to the origin, attachments, insertion, distribution, branching pattern and gross structure. Terminologies defined are as follows. Apical pillar chordae, Basal pillar chordae, True chordae, False chordae, Interpillar chordae, Pillar wall chordae, Cusp chordae, Cleft chordae, Commissural chordae, First order chordae, Second order chordae, Free zone chordae, Marginal chordae, Rough zone chordae, Straight chordae, Branched-fan shaped chordae, Spiral chordae, Irregular-web chordae, Tendinous chordae, Muscular chordae, Membranous chordae. Basal pillar chordae are found in 9.48%. Mean number of chordae taking origin from apical half of a single papillary muscle or single head of papillary muscle was 9.09 with the range of 3-18. Mean number of the marginal chordae attached to a single cusp was 22.63 ranging from 11 to 35. Strut chordae showed interesting insertion with broad aponeurosis in 38.79% and large muscular flaps in 13.79%. Chordae muscularis were found in 14% and membranous chordae were found in 6%. Conclusions: This knowledge may prove useful for cardiologists and cardiac surgeons.
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Affiliation(s)
- S A Gunnal
- Department of Anatomy, Rural Medical College, Maharashtra, India
| | - R N Wabale
- Department of Anatomy, Rural Medical College, Maharashtra, India
| | - M S Farooqui
- Department of Anatomy, Rural Medical College, Maharashtra, India
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Wakasa S, Matsui Y. Benefits of submitral procedures for ischemic mitral regurgitation. Gen Thorac Cardiovasc Surg 2014; 62:511-5. [PMID: 25022809 DOI: 10.1007/s11748-014-0453-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Indexed: 10/25/2022]
Abstract
The surgical strategy for ischemic mitral regurgitation (MR) remains controversial. Ischemic MR is a secondary valve disease caused by left ventricular (LV) remodeling and subsequent papillary muscle displacement, usually without structural valve lesions. Reduction annuloplasty is the standard surgical procedure for this condition, though it cannot clearly provide a survival benefit for those with LV dysfunction and is associated with a high prevalence of late recurrence of MR. The valvular procedure alone could be insufficient to treat ischemic MR in terms of long-term survival and the prevention of recurrence because ischemic MR is primarily a ventricular disorder. Thus, recent studies have focused on alternative procedures that target the primary cause of ischemic MR, the papillary muscles and left ventricle. We believe that the appropriate selection of surgical procedures among valvular, subvalvular, and even ventricular ones, considering the severity of LV remodeling for each patient would be more beneficial. Here we review recent studies featuring various surgical approaches to ischemic MR, especially with submitral procedures.
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Affiliation(s)
- Satoru Wakasa
- Department of Cardiovascular and Thoracic Surgery, Hokkaido University Graduate School of Medicine, Kita-15, Nishi-7, Kita-ku, Sapporo, 060-8638, Japan
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23
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Da Col U, Di Lazzaro D, Affronti A, Perticoni S, Ragni T. Nine Years' Experience with the Chordal Cutting Technique in Ischemic Mitral Regurgitation. J Card Surg 2014; 29:605-8. [DOI: 10.1111/jocs.12392] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Uberto Da Col
- S.C. Cardiochirurgia; Ospedale S. Maria della Misericordia, Azienda Ospedaliera di Perugia; Perugia Italy
| | - Davide Di Lazzaro
- S.C. Cardiochirurgia; Ospedale S. Maria della Misericordia, Azienda Ospedaliera di Perugia; Perugia Italy
| | - Alessandro Affronti
- S.C. Cardiochirurgia; Ospedale S. Maria della Misericordia, Azienda Ospedaliera di Perugia; Perugia Italy
| | - Simone Perticoni
- S.C. Cardiochirurgia; Ospedale S. Maria della Misericordia, Azienda Ospedaliera di Perugia; Perugia Italy
| | - Temistocle Ragni
- S.C. Cardiochirurgia; Ospedale S. Maria della Misericordia, Azienda Ospedaliera di Perugia; Perugia Italy
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24
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Codreanu I, Robson MD, Rider OJ, Pegg TJ, Dasanu CA, Jung BA, Clarke K, Holloway CJ. Effects of ventricular insertion sites on rotational motion of left ventricular segments studied by cardiac MR. Br J Radiol 2014; 86:20130326. [PMID: 24133098 DOI: 10.1259/bjr.20130326] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE Obtaining new details for rotational motion of left ventricular (LV) segments using velocity encoding cardiac MR and correlating the regional motion patterns to LV insertion sites. METHODS Cardiac MR examinations were performed on 14 healthy volunteers aged between 19 and 26 years. Peak rotational velocities and circumferential velocity curves were obtained for 16 ventricular segments. RESULTS Reduced peak clockwise velocities of anteroseptal segments (i.e. Segments 2 and 8) and peak counterclockwise velocities of inferoseptal segments (i.e. Segments 3 and 9) were the most prominent findings. The observations can be attributed to the LV insertion sites into the right ventricle, limiting the clockwise rotation of anteroseptal LV segments and the counterclockwise rotation of inferoseptal segments as viewed from the apex. Relatively lower clockwise velocities of Segment 5 and counterclockwise velocities of Segment 6 were also noted, suggesting a cardiac fixation point between these two segments, which is in close proximity to the lateral LV wall. CONCLUSION Apart from showing different rotational patterns of LV base, mid ventricle and apex, the study showed significant differences in the rotational velocities of individual LV segments. Correlating regional wall motion with known orientation of myocardial aggregates has also provided new insights into the mechanisms of LV rotational motions during a cardiac cycle. ADVANCES IN KNOWLEDGE LV insertion into the right ventricle limits the clockwise rotation of anteroseptal LV segments and the counterclockwise rotation of inferoseptal segments adjacent to the ventricular insertion sites. The pattern should be differentiated from wall motion abnormalities in cardiac pathology.
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Affiliation(s)
- I Codreanu
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
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Murashita T, Okada Y, Kanemitsu H, Fukunaga N, Konishi Y, Nakamura K, Koyama T. Midterm outcomes of chordal cutting in combination with downsized ring annuloplasty for ischemic mitral regurgitation. Ann Thorac Cardiovasc Surg 2014; 20:1008-15. [PMID: 24492174 DOI: 10.5761/atcs.oa.13-00293] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
PURPOSE We describe midterm outcomes after division of secondary chords (chordal cutting) combined with downsized ring annuloplasty for ischemic mitral regurgitation (IMR). METHODS We compared the clinical outcomes in patients who underwent chordal cutting with downsized ring annuloplasty (CC-group, n = 15) and those who underwent conventional ring annuloplasty only (Conventional-group, n = 35) for IMR. Follow-up was complete in all patients. The median follow-up time was 4.1 years. RESULTS Thirty-day mortality was 0% in CC-group and 20% in Conventional-group. The overall survival rate at 5-year was 80.8% ± 12.6% in CC-group and 61.7% ± 8.4% in Conventional-group (Log-rank, p = 0.145). The freedom rate from valve-related events at 5 year was 84.6% ± 10.0% in CC-group and 65.3% ± 10.1% in Conventional-group (Log-rank, p = 0.213). Recurrence of severe mitral regurgitation was revealed in 3 patients of CC-group. Preoperative tenting height was the significant predictor of mitral regurgitation recurrence. In CC-group, the mean left ventricular ejection fraction was 38.0% ± 14.0%, which was similar to the preoperative value of 40.0% ± 13.2% (p = 0.349). CONCLUSIONS Chordal cutting with downsized ring annuloplasty for IMR is a simple method and provides satisfactory early outcomes. However, it carries with high recurrence of MR especially for patients with high tenting height.
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Affiliation(s)
- Takashi Murashita
- Department of Cardiovascular Surgery, Kobe City Medical Center General Hospital, Kobe, Hyogo, Japan
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Askov JB, Honge JL, Jensen MO, Nygaard H, Hasenkam JM, Nielsen SL. Significance of force transfer in mitral valve–left ventricular interaction: In vivo assessment. J Thorac Cardiovasc Surg 2013; 145:1635-41, 1641.e1. [DOI: 10.1016/j.jtcvs.2012.07.062] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Revised: 07/10/2012] [Accepted: 07/26/2012] [Indexed: 11/26/2022]
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Darvishi S, Behnam H, Pouladian M, Samiei N. Measuring Left Ventricular Volumes in Two-Dimensional Echocardiography Image Sequence Using Level-set Method for Automatic Detection of End-Diastole and End-systole Frames. Res Cardiovasc Med 2013; 2:39-45. [PMID: 25478488 PMCID: PMC4253755 DOI: 10.5812/cardiovascmed.6397] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Revised: 02/01/2012] [Accepted: 02/09/2012] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Identifying End-Diastole (ED) and End-Systole (ES) frames is highly important in the process of evaluating cardiac function and measuring global parameters accurately, such as Ejection Fraction (EF), Cardiac Output (CO) and Stroke Volume. OBJECTIVES The current study aimed to develop a new method based on measuring volume changes in Left Ventricle (LV) during cardiac cycle. MATERIAL AND METHODS For this purpose, the Level Set method was used both in detecting endocardium border and quantifying cardiac function of all frames. RESULTS Demonstrating LV volumes displays ED and ES frames and the volumes used in calculating the required parameters. CONCLUSIONS Since ES and ED frames exist in iso-volumic phases of the cardiac cycle with minimum and maximum values of LV volume signals, such peaks can be utilized in finding related frames.
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Affiliation(s)
- Saeed Darvishi
- Faculty of Biomedical Engineering, Department of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, IR Iran
- Corresponding author: Saeed Darvishi, Faculty of Biomedical Engineering, Department of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, IR Iran. Tel.: +98-2144444330, Fax: +98-2144444331, E-mail: s.
| | - Hamid Behnam
- Department of the Electronic Engineering, Iran University of Science and Technology, Tehran, IR Iran
| | - Majid Pouladian
- Department of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, IR Iran
| | - Niloufar Samiei
- Echocardiography Research Center, Rajaie Cardiovascular Medical and Research Center, Tehran University of Medical Sciences, Tehran, IR Iran
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Timek TA, Miller DC. Another multidisciplinary look at ischemic mitral regurgitation. Semin Thorac Cardiovasc Surg 2012; 23:220-31. [PMID: 22172360 DOI: 10.1053/j.semtcvs.2011.07.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/21/2011] [Indexed: 12/31/2022]
Abstract
Ischemic mitral regurgitation (IMR) continues to challenge surgeons and scientists alike. This vexing clinical entity frequently complicates myocardial infarction and carries a poor prognosis both in the setting of coronary disease and idiopathic dilated cardiomyopathy. Ischemic mitral regurgitation encompasses a difficult patient population that is characterized by high operative mortality, poor long term outcomes, and frequent recurrent insufficiency after standard surgical repair. Yet optimal surgical repair and improved clinical outcomes can only be achieved with better knowledge of the pathophysiology of IMR which is still incompletely understood. The causative mechanism of IMR appears to lie in the annular and subvalvular frame of the valve rather than leaflet or chordal structure leading to such labels as "ischemic," "functional," "non-organic," and "cardiomyopathy associated" being applied in the clinical literature. Although ischemic mitral regurgitation is a prevailing clinical entity, it has not been consistently defined in the literature, contributing to considerable confusion and contradictory results of clinical studies. As the mechanisms of pathophysiology have been better elucidated, novel surgical and interventional strategies have been developed recently to provide better treatment for this difficult patient population. In this review, we undertake a multidisciplinary update of the pathophysiology, classification, and surgical and interventional treatment of ischemic mitral regurgitation in today's clinical practice.
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Affiliation(s)
- Tomasz A Timek
- West Michigan Cardiothoracic Surgeons and Spectrum Health System, Grand Rapids, Michigan, USA
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Roosens B, Bala G, Droogmans S, Van Camp G, Breyne J, Cosyns B. Animal models of organic heart valve disease. Int J Cardiol 2012; 165:398-409. [PMID: 22475840 DOI: 10.1016/j.ijcard.2012.03.065] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Revised: 02/18/2012] [Accepted: 03/03/2012] [Indexed: 01/23/2023]
Abstract
Heart valve disease is a frequently encountered pathology, related to high morbidity and mortality rates in industrialized and developing countries. Animal models are interesting to investigate the causality, but also underlying mechanisms and potential treatments of human valvular diseases. Recently, animal models of heart valve disease have been developed, which allow to investigate the pathophysiology, and to follow the progression and the potential regression of disease with therapeutics over time. The present review provides an overview of animal models of primary, organic heart valve disease: myxoid age-related, infectious, drug-induced, degenerative calcified, and mechanically induced valvular heart disease.
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Affiliation(s)
- Bram Roosens
- Centrum Voor Hart- en Vaatziekten (CHVZ), Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel (VUB), Brussels, Belgium.
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Padala M, Gyoneva L, Yoganathan AP. Effect of anterior strut chordal transection on the force distribution on the marginal chordae of the mitral valve. J Thorac Cardiovasc Surg 2011; 144:624-633.e2. [PMID: 22154223 DOI: 10.1016/j.jtcvs.2011.10.032] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Revised: 09/12/2011] [Accepted: 10/20/2011] [Indexed: 11/27/2022]
Abstract
OBJECTIVES Transection of the secondary chordae on the anterior leaflet of the mitral valve to relieve leaflet tethering and reduce regurgitation is an experimentally proven procedure to correct functional mitral regurgitation. In the present study, we sought to investigate whether transecting the secondary chordae would have an effect on the marginal chordal force on the same leaflet. METHODS Adult porcine mitral valves (n = 8) were studied in a pulsatile heart simulator, in which the papillary muscle positions can be precisely positioned. Miniature transducers were inserted into the anterior marginal chordae to measure the chordal forces. Each valve was studied under baseline conditions, 3 different tethering conditions (apical, apical-lateral, and apical-lateral-posterior), and after chordal cutting in the 3 tethering conditions. The temporal changes and peak and average marginal chordal forces under each condition are reported. RESULTS Apical tethering increased the marginal chordal force by an average of 96% but remained unchanged after chordal cutting. With apical-lateral tethering, the marginal chordal force increased by 210% from baseline and increased further to 350% of baseline after chordal cutting. After apical-lateral-posterior tethering, the marginal chordal force increased to 335% of baseline before transection and by 548% after transection. CONCLUSIONS The increase in the marginal chordal force after secondary chordal cutting depends on the location of the papillary muscles and the extent of leaflet tethering. Although chordal cutting might not alter the valve mechanics under minimal leaflet tethering, it significantly affects the mechanics when the leaflet tethering is more pronounced, which is typically seen in patients with functional mitral regurgitation.
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Affiliation(s)
- Muralidhar Padala
- Division of Cardiothoracic Surgery, Emory University School of Medicine, Atlanta, GA, USA
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Abstract
PURPOSE OF REVIEW Despite improvements in surgical techniques, valvular regurgitation results in major morbidity in children with heart disease. Functional anatomy, mechanisms of valve closure and adaptation to changing hemodynamic stress in normal mitral and tricuspid valves are complex and only partially understood. As well, pathology of atrioventricular valve regurgitation is further complicated by congenital valve abnormalities involving leaflet tissue, supporting chordal apparatus and displaced papillary muscles. This review provides a current understanding of the mechanisms that result in atrioventricular valve failure. RECENT FINDINGS Mitral valve leaflets have contractile elements, in addition to atrial muscle modulation of leaflet tension. When placed under mechanical tethering stress, the mitral valve adapts by leaflet expansion, which increases coaptation surface reserve and chordal thickening. Both pediatric and adult studies are increasingly reporting on the importance of subvalvar apparatus function in maintaining valve competency. SUMMARY The maintenance of efficient valve function is accomplished by a complex series of events involving atrial and annular contraction, annular deformation, active leaflet tension, chordal transmission of papillary muscle contractions and ventricular contraction.
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Affiliation(s)
- Nee S Khoo
- Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada
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Salhiyyah K, Yacoub MH, Chester AH. Cellular mechanisms in mitral valve disease. J Cardiovasc Transl Res 2011; 4:702-9. [PMID: 21892743 DOI: 10.1007/s12265-011-9318-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Accepted: 08/15/2011] [Indexed: 01/23/2023]
Abstract
The mitral valve is a living structure comprised of specific structural components which contain a heterogeneous population of cells. The cells include an amalgam of interstitial cells within the valve and a continuous covering of endothelial cells, each of which play a role in responding to the mechanical forces that the valve experiences, to maintain the function and durability of the valve. Attention on the characteristics and function of valve cells has focused mainly on those in the aortic valve, with relatively few studies addressing the role of these cells in the physiological and pathophysiological function of the mitral valve. This article reviews what is known about the function of cells within the mitral valve and how the changes in the physical and chemical environments can affect their function in the different types of mitral valve disease. Investigating the contribution of the cellular components of the mitral valve to valve function in health and disease will aid the understanding of how the durability and function of the valve are regulated, and possibly highlight molecular and pharmacological targets for the development of novel treatments for mitral valve disease.
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Affiliation(s)
- Kareem Salhiyyah
- Imperial College London, Heart Science Centre, Harefield, Middlesex, UB9 6JH, UK
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Mechanistic Insights into Ischemic Mitral Regurgitation: Echocardiographic and Surgical Implications. J Am Soc Echocardiogr 2011; 24:707-19. [DOI: 10.1016/j.echo.2011.04.001] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Indexed: 11/24/2022]
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Messas E, Bel A, Szymanski C, Cohen I, Touchot B, Handschumacher MD, Desnos M, Carpentier A, Menasché P, Hagège AA, Levine RA. Relief of mitral leaflet tethering following chronic myocardial infarction by chordal cutting diminishes left ventricular remodeling. Circ Cardiovasc Imaging 2010; 3:679-86. [PMID: 20826595 DOI: 10.1161/circimaging.109.931840] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND one of the key targets in treating mitral regurgitation (MR) is reducing the otherwise progressive left ventricular (LV) remodeling that exacerbates MR and conveys adverse prognosis. We have previously demonstrated that severing 2 second-order chordae to the anterior mitral leaflet relieves tethering and ischemic MR acutely. The purpose of this study was to test whether this technique reduces the progression of LV remodeling in the chronic ischemic MR setting. METHODS AND RESULTS a posterolateral MI was created in 18 sheep by obtuse marginal branch ligation. After chronic remodeling and MR development at 3 months, 6 sheep were randomized to sham surgery (control group) and 12 to second-order chordal cutting (6 each to anterior leaflet [AntL] and bileaflet [BiL] chordal cutting, techniques that are in clinical application). At baseline, chronic infarction (3 months), and follow-up at a mean of 6.6 months post-myocardial infarction (MI) (euthanasia), we measured LV end-diastolic (EDV) and end-systolic volume (ESV), ejection fraction, wall motion score index, and posterior leaflet (PL) restriction angle relative to the annulus by 2D and 3D echocardiography. All measurements were comparable among groups at baseline and chronic MI. At euthanasia, AntL and BiL chordal cutting limited the progressive remodeling seen in controls. LVESV increased relative to chronic MI by 109±8.7% in controls versus 30.5±6.1% with chordal cutting (P<0.01) (LVESV in controls, 82.5±2.6 mL; in AntL, 60.6±5.1 mL; in BiL, 61.8±4.1 mL). LVEDV increased by 63±2.0% in controls versus 26±5.5% and 22±3.4% with chordal cutting (P<0.01). LV ejection fraction and wall motion score index were not significantly different at follow-up among the chordal cutting and control groups. MR progressively increased to moderate in controls but decreased to trace-mild with AntL and BiL chordal cutting (MR vena contracta in controls, 5.9±1.1 mm; in AntL, 2.6±0.1 mm; in BiL, 1.7±0.1 mm; P<0.01). BiL chordal cutting provided greater PL mobility (decreased PL restriction angle to 54.2±5.0° versus 83±3.2° with AntL chordal cutting; P<0.01). CONCLUSIONS reduced leaflet tethering by chordal cutting in the chronic post-MI setting substantially decreases the progression of LV remodeling with sustained reduction of MR over a chronic follow-up. These benefits have the potential to improve clinical outcomes.
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Affiliation(s)
- Emmanuel Messas
- Hôpital Européen Georges Pompidou, Department of Cardiology, University Paris Descartes, Paris.
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Silbiger JJ, Bazaz R. Contemporary insights into the functional anatomy of the mitral valve. Am Heart J 2009; 158:887-95. [PMID: 19958853 DOI: 10.1016/j.ahj.2009.10.014] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2009] [Accepted: 10/13/2009] [Indexed: 11/29/2022]
Abstract
The mitral valve is a highly complex structure the normal functioning of which requires the coordinated interaction of the leaflets, annulus, chordae tendineae, and papillary muscles. Perturbations of any of these components can interfere with normal valve function. The integrity of the mitral valve is also essential to maintaining normal left ventricular geometry and function through closely coupled ventricular-valvular interactions. This review summarizes recent developments in our understanding of the anatomy and physiology of the mitral valve.
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Affiliation(s)
- Jeffrey J Silbiger
- Department of Cardiology, Mount Sinai Services at Elmhurst Hospital Center, Mount Sinai School of Medicine, New York, NY, USA.
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Affiliation(s)
- Yoshiro Matsui
- Department of Cardiovascular Surgery, Hokkaido University Hospital
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Mynard J, Penny D, Smolich J. Accurate Automatic Detection of End-Diastole From Left Ventricular Pressure Using Peak Curvature. IEEE Trans Biomed Eng 2008; 55:2651-7. [DOI: 10.1109/tbme.2008.2001295] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Carlhäll CJ, Nguyen TC, Itoh A, Ennis DB, Bothe W, Liang D, Ingels NB, Miller DC. Alterations in transmural myocardial strain: an early marker of left ventricular dysfunction in mitral regurgitation? Circulation 2008; 118:S256-62. [PMID: 18824764 DOI: 10.1161/circulationaha.107.753525] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND In asymptomatic patients with severe isolated mitral regurgitation (MR), identifying the onset of early left ventricular (LV) dysfunction can guide the timing of surgical intervention. We hypothesized that changes in LV transmural myocardial strain represent an early marker of LV dysfunction in an ovine chronic MR model. METHODS AND RESULTS Sheep were randomized to control (CTRL, n=8) or experimental (EXP, n=12) groups. In EXP, a 3.5- or 4.8-mm hole was created in the posterior mitral leaflet to generate "pure" MR. Transmural beadsets were inserted into the lateral and anterior LV wall to radiographically measure 3-dimensional transmural strains during systole and diastolic filling, at 1 and 12 weeks postoperatively. MR grade was higher in EXP than CTRL at 1 and 12 weeks (3.0 [2-4] versus 0.5 [0-2]; 3.0 [1-4] versus 0.5 [0-1], respectively, both P<0.001). At 12 weeks, LV mass index was greater in EXP than CTRL (201+/-18 versus 173+/-17 g/m(2); P<0.01). LVEDVI increased in EXP from 1 to 12 weeks (P=0.015). Between the 1 and 12 week values, the change in BNP (-4.5+/-4.4 versus -3.0+/-3.6 pmol/L), PRSW (9+/-13 versus 23+/-18 mm Hg), tau (-3+/-11 versus -4+/-7 ms), and systolic strains was similar between EXP and CTRL. The changes in longitudinal diastolic filling strains between 1 and 12 weeks, however, were greater in EXP versus CTRL in the subendocardium (lateral: -0.08+/-0.05 versus 0.02+/-0.14; anterior: -0.10+/-0.05 versus -0.02+/-0.07, both P<0.01). CONCLUSIONS Twelve weeks of ovine "pure" MR caused LV remodeling with early changes in LV function detected by alterations in transmural myocardial strain, but not by changes in BNP, PRSW, or tau.
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Affiliation(s)
- Carl J Carlhäll
- Department of Cardiothoracic Surgery, Falk Cardiovascular Research Center, Stanford University School of Medicine, Stanford, CA 94305-5247, USA
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Stephens EH, Nguyen TC, Itoh A, Ingels NB, Miller DC, Grande-Allen KJ. The effects of mitral regurgitation alone are sufficient for leaflet remodeling. Circulation 2008; 118:S243-9. [PMID: 18824762 DOI: 10.1161/circulationaha.107.757526] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Although chronic mitral regurgitation results in adverse left ventricular remodeling, its effect on the mitral valve leaflets per se is unknown. In a chronic ovine model, we tested whether isolated mitral regurgitation alone was sufficient to remodel the anterior mitral leaflet. METHODS AND RESULTS Twenty-nine sheep were randomized to either control (CTRL, n=11) or experimental (HOLE, n=18) groups. In HOLE, a 2.8- to 4.8-mm diameter hole was punched in the middle scallop of the posterior mitral leaflet to create "pure" mitral regurgitation. At 12 weeks, the anterior mitral leaflet was analyzed immunohistochemically to assess markers of collagen and elastin synthesis as well as matrix metalloproteinases and proteoglycans. A semiquantitative grading scale for characteristics such as intensity and delineation of stain between layers was used to quantify differences between HOLE and CTRL specimens across the heterogeneous leaflet structure. At 12 weeks, mitral regurgitation grade was greater in HOLE versus CTRL (3.0+/-0.8 versus 0.4+/-0.4, P<0.001). In HOLE anterior mitral leaflet, saffron-staining collagen (Movat) decreased, consistent with an increase in matrix metalloproteases throughout the leaflet. Type III collagen expression was increased in the midleaflet and free edge and expression of prolyl-4-hydroxylase (indicating collagen synthesis) was increased in the spongiosa layer. The proteoglycan decorin, also involved in collagen fibrillogenesis, was increased compared with CTRL (all P</=0.05). CONCLUSIONS In HOLE anterior mitral leaflet, the increased expression of proteins related to collagen synthesis and matrix degradation suggests active matrix turnover. These are the first observations showing that regurgitation alone can stimulate mitral leaflet remodeling. Such leaflet remodeling needs to be considered in reparative surgical techniques.
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Nguyen TC, Itoh A, Carlhäll CJ, Bothe W, Timek TA, Ennis DB, Oakes RA, Liang D, Daughters GT, Ingels NB, Miller DC. The effect of pure mitral regurgitation on mitral annular geometry and three-dimensional saddle shape. J Thorac Cardiovasc Surg 2008; 136:557-65. [PMID: 18805251 DOI: 10.1016/j.jtcvs.2007.12.087] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2007] [Revised: 11/26/2007] [Accepted: 12/18/2007] [Indexed: 10/21/2022]
Abstract
OBJECTIVE Chronic ischemic mitral regurgitation is associated with mitral annular dilatation in the septal-lateral dimension and flattening of the annular 3-dimensional saddle shape. To examine whether these perturbations are caused by the ischemic insult, mitral regurgitation, or both, we investigated the effects of pure mitral regurgitation (low pressure volume overload) on annular geometry and shape. METHODS Eight radiopaque markers were sutured evenly around the mitral annulus in sheep randomized to control (CTRL, n = 8) or experimental (HOLE, n = 12) groups. In HOLE, a 3.5- to 4.8-mm hole was punched in the posterior leaflet to generate pure mitral regurgitation. Four-dimensional marker coordinates were obtained radiographically 1 and 12 weeks postoperatively. Mitral annular area, annular septal-lateral and commissure-commissure dimensions, and annular height were calculated every 16.7 ms. RESULTS Mitral regurgitation grade was 0.4 +/- 0.4 in CTRL and 3.0 +/- 0.8 in HOLE (P < .001) at 12 weeks. End-diastolic left ventricular volume index was greater in HOLE at both 1 and 12 weeks; end-systolic volume index was larger in HOLE at 12 weeks. Mitral annular area increased in HOLE predominantly in the commissure-commissure dimension, with no difference in annular height between HOLE versus CTRL at 1 or 12 weeks, respectively. CONCLUSION In contrast with annular septal-lateral dilatation and flattening of the annular saddle shape observed with chronic ischemic mitral regurgitation, pure mitral regurgitation was associated with commissure-commissure dimension annular dilatation and no change in annular shape. Thus, infarction is a more important determinant of septal-lateral dilatation and annular shape than mitral regurgitation, which reinforces the need for disease-specific designs of annuloplasty rings.
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Affiliation(s)
- Tom C Nguyen
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, California 94305-5247, USA
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Mabrouk-Zerguini N, Léger P, Aubert S, Ray R, Leprince P, Riou B, Coriat P, Ouattara A. Tei index to assess perioperative left ventricular systolic function in patients undergoing mitral valve repair. Br J Anaesth 2008; 101:479-85. [PMID: 18640993 DOI: 10.1093/bja/aen212] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Using echocardiography, perioperative assessment of systolic function by fractional area change (FAC) is questionable in patients suffering from mitral regurgitation (MR). Tei index, an index expressing global cardiac function, has been reported to be unchanged after mitral valve surgery. We tested the hypothesis where the Tei index could be useful in assessing the perioperative cardiac function in patients undergoing mitral valve repair (MVR). METHODS Twenty-five patients were enrolled. Transoesophageal echocardiography was performed perioperatively before and after the correction of MR. We compared the impact of the MVR on the left ventricular FAC and the Tei index. FAC was calculated from the transgastric short-axis view and Tei index was determined from the four chambers and deep transgastric views. RESULTS Two patients were excluded because of poor acoustic windows. FAC significantly decreased after MVR from 53 (9)% to 42 (10)% (P<0.001), while Tei index was unaffected [0.46 (0.16) vs 0.47 (0.17), NS]. A significant relationship was found between the preoperative Tei index and the postoperative FAC (R=-0.64, P<0.001). Moreover, a significant and clinically relevant relationship was determined between the predicted (using preoperative Tei index) and the measured postoperative FAC (R=0.64, P<0.001). CONCLUSIONS FAC but not the Tei index is influenced by MVR. The preoperative determination of the Tei index allows predicting postoperative FAC and offers the opportunity to identify patients in whom a severe unsuspected systolic dysfunction could render difficult the weaning from cardiopulmonary bypass.
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Affiliation(s)
- N Mabrouk-Zerguini
- Department of Anaesthesiology and Critical Care, Centre Hospitalier Universitaire Pitié-Salpêtrière, UMPC Univ Paris 06, F-75013 Paris, France
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Fazel SS, Ihlberg L, David TE. Mitral valve reconstruction in the failing heart. Scand J Surg 2007; 96:111-20. [PMID: 17679352 DOI: 10.1177/145749690709600205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- S S Fazel
- Peter Munk Cardiac Centre, Division of Cardiac Surgery, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada.
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Kheradvar A, Milano M, Gharib M. Correlation Between Vortex Ring Formation and Mitral Annulus Dynamics During Ventricular Rapid Filling. ASAIO J 2007; 53:8-16. [PMID: 17237643 DOI: 10.1097/01.mat.0000249870.44625.22] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
One of the most important fluid phenomena observed in the left ventricle during diastole is the presence of vortex rings that develop with a strong jet entering through the mitral valve. The present study is focused on the rapid filling phase of diastole, during which the left ventricle expands and receives blood through the fully open mitral valve. The atrioventricular system during the rapid filling phase was emulated experimentally with a simplified mechanical model in which the relevant pressure decay and the dimension of mitral annulus approximate the physiologic and pathologic values. Digital particle image velocimetry measurements were correlated with the force measurements on the mitral annulus plane to analyze the relation between flow and the mitral annulus motion. The recoil force on the displaced annulus plane was computed on the basis of plane acceleration and plane velocity and correlated with the inflow jet. Measurements of the recoil force for different values of the mitral annulus diameter showed that the recoil force was generated during fluid propulsion and that it is maximal for an annulus diameter close to the normal adult value in a healthy left ventricle. We also tested annulus diameters smaller and larger than the normal one. The smaller annulus corresponds to the stenotic valves and the larger annulus exists in dilated cardiomyopathy cases. In both conditions, the recoil force was found to be smaller than in the normal case. These observations are consistent with the previously reported results for dilated cardiomyopathy and mitral stenosis clinical conditions.
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Affiliation(s)
- Arash Kheradvar
- Cardiovascular and Biofluid Dynamics Laboratory, California Institute of Technology, Pasadena, California 91125, USA
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A. Levine R, Otsuji Y, Schwammenthal E, Sakata R, Tei C. Ischemic Mitral Regurgitation: From New Understanding to New Solutions Role of Echocardiography. J Echocardiogr 2006. [DOI: 10.2303/jecho.4.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Affiliation(s)
- Robert A Levine
- Massachusetts General Hospital, Department of Medicine, Harvard Medical School, Boston, MA, USA.
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Rodriguez F, Langer F, Harrington KB, Tibayan FA, Zasio MK, Liang D, Daughters GT, Ingels NB, Miller DC. Cutting second-order chords does not prevent acute ischemic mitral regurgitation. Circulation 2005; 110:II91-7. [PMID: 15364845 DOI: 10.1161/01.cir.0000138396.24335.6a] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Cutting anterior mitral leaflet second-order chordae has been proposed for repair in ischemic mitral regurgitation (IMR). We examined the efficacy of such chordal cutting in preventing acute IMR. METHODS AND RESULTS Six sheep underwent radiopaque marker placement (left ventricle, mitral annulus, papillary muscles [PMs], and leaflets). The largest second-order chord from each PM was encircled with exteriorized wire snares. Three-dimensional marker coordinates were obtained with biplane videofluoroscopy before and during acute ischemia (80 seconds of mid-circumflex occlusion). Color Doppler transesophageal echocardiography was used to grade MR on a 0 to 4+ scale. Data were acquired immediately before and after dividing second-order chordae. Slope of the end-diastolic volume-stroke work relationship (PRSW) was calculated to assess systolic function. Chordal cutting increased anterior leaflet inflection angle (155+/-12 versus 162+/-9 degrees; P=0.03), resulting in a flatter leaflet, but did not increase effective leaflet length (1.97+/-0.24 versus 2.08+/-0.23 cm; P=0.15); PRSW decreased (63+/-15 versus 56+/-12 mm Hg; P=0.008). Both before and after chordal cutting, ischemia caused: Septal-lateral annular dilation (P=0.005), posterior PM displacement away from the mid-septal annulus (P=0.06), increased leaflet tenting area (P=0.001), and increased leaflet tenting volume (P=0.002). Before chordal cutting, MR increased significantly during ischemia (0.5+/-0.3 versus 1.7+/-0.4; P<0.001), and IMR increased similarly even after the second-order chords were cut (0.7+/-0.4 versus 1.9+/-0.9; P<0.001). CONCLUSIONS Cutting second-order chordae resulted in LV systolic dysfunction and neither prevented nor decreased the severity of acute IMR, septal-lateral annular dilation, leaflet tenting area, or leaflet tenting volume.
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Affiliation(s)
- Filiberto Rodriguez
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, Calif 94305-5247, USA
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Rodriguez F, Langer F, Harrington KB, Cheng A, Daughters GT, Criscione JC, Ingels NB, Miller DC. Alterations in transmural strains adjacent to ischemic myocardium during acute midcircumflex occlusion. J Thorac Cardiovasc Surg 2005; 129:791-803. [PMID: 15821645 DOI: 10.1016/j.jtcvs.2004.11.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE Helically oriented left ventricular fibers assemble into transmural sheets, which are important for wall-thickening mechanics: 15% fiber shortening results in 40% cross-fiber left ventricular wall thickening and a 60% ejection fraction through sheet extension, thickening, and shear. Normal cardiac microstructure and strains are optimized; deviations could result in apoptosis and deleterious matrix remodeling, which degenerates into global cardiomyopathy. We studied alterations in transmural strains adjacent to ischemic myocardium during acute midcircumflex occlusion. METHODS Nine sheep had radiopaque markers implanted to measure left ventricular systolic fractional area shortening; 3 transmural bead columns were inserted into the midlateral wall for strain analysis. Three-dimensional marker coordinates were obtained with biplane videofluoroscopy before and during 70 seconds of ischemia. Systolic strains were quantified along circumferential, longitudinal, and radial axes (n = 9) and were transformed into fiber-sheet coordinates by using quantitative microstructural measurements (n = 5). RESULTS A functional border was defined in the midlateral left ventricle; ischemia decreased posterolateral fractional area shortening, and anterolateral fractional area shortening increased. In this demarcation junction, subepicardial end-systolic radial wall thickening decreased (0.16 +/- 0.08 vs 0.11 +/- 0.06) and sheet-normal shear was abolished (0.08 +/- 0.04 vs -0.01 +/- 0.03). Longitudinal shortening decreased in the subepicardium and midwall (-0.05 +/- 0.04 vs +/- -0.01 +/- 0.06), but circumferential-radial shear increased at these depths (0.04 +/- 0.04 vs 0.11 +/- 0.05). Subendocardial fiber stretch occurred during early systole (-0.01 +/- 0.03 vs 0.02 +/- 0.03), and end-systolic fiber-sheet shear increased (0.07 +/- 0.01 vs 0.11 +/- 0.04, all P < .05). CONCLUSIONS Increased circumferential-radial shear and altered fiber-sheet strains reflect mechanical interactions between ischemic and nonischemic myocardium, which might be important in triggering remodeling processes that evolve into global ischemic cardiomyopathy.
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Affiliation(s)
- Filiberto Rodriguez
- Department of Cardiothoracic Surgery, Stanford University School of Medcine, Stanford, CA 94305-5247, USA
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