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1.
Curr Probl Cardiol ; 49(1 Pt A): 102063, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37648041

RESUMO

To develop a mathematical formula for calculating the length of ruptured mitral valve chordae (with a view to surgically replacing them with artificial chordae) when rupture occurs at scallop A1, A3, P1, or P3. We studied human cadaver hearts collected by the Faculty of Medicine at Amiens Picardy University Hospital. The donors' mean age standard deviation age at death was 79 ± 10. After weighing and dissection, we counted the number of para-commissural chordae per scallop and measured their length with a digital calliper. A total of 31 human cadaver hearts (14 from females and 17 from males) were analyzed. The mean lengths of scallops A1, A2, A3, P1, P2, and P3 were 17.45, 19.42, 17.58, 13.32, 14.52, and 13.26 mm, respectively. A linear regression gave the following mathematical equations: A1 = 0.96 × A2- - 1.3 (R: 0.99; P < 0.001); A3 = 0.9 × A2 + 0.17 (R: 0.95; P < 0.01); P1 = 0.87 × P2 +0.74 (R: 0.89; P < 0.001), and P3 = 0.91 × P2 - 0.01 (R: 0.87; P < 0.0001). When the patient's anatomy prevents manual measurements of the chordae during mitral valve repair surgery, the mathematical formulae derived here can be used to predict the length of the chordae on A1, A3, P1, and P3 from the length of the chordae on A2 and P2. The mitral chordae can therefore be replaced with prostheses with a great degree of precision.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Insuficiência da Valva Mitral , Masculino , Feminino , Humanos , Valva Mitral/cirurgia , Cordas Tendinosas/cirurgia , Cordas Tendinosas/anatomia & histologia , Insuficiência da Valva Mitral/cirurgia , Cadáver
2.
Anat Histol Embryol ; 52(6): 927-935, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37485820

RESUMO

This study aimed to provide comparative anatomical data on the mitral valve and to substantiate the choice between large species for pre-clinical testing of cardiac devices. Different anatomical parameters of the anterior and posterior leaflets, chordae and papillary muscles were measured to characterize the anatomy of the mitral valve in 10 individuals for each four species. Ratios were calculated and used to circumvent the interspecies variations of body and heart size and weight. The results underline many relevant anatomical similarities and differences between man and the three animal species. We confirm that the porcine species is a better model based on anatomical measurements. But many parameters should be considered depending on the shape, size and purpose of the device. The mitral and aortic valve are closer than in man leading to potential damage of the aortic valve by a mitral device. The ovine mitral annulus is more flattened and would sustain more mechanical forces on a round-shaped stent. The anterior and posterior leaflets have comparable height in the animal species leading to more space for implantation. The porcine valve has more chordae allowing less space around the valve for a transcatheter stent. Our observations introduce new comparative data in the perspective of the choice of a large animal model for pre-clinical testing of mitral devices. They are very helpful for all cardiologists, surgeons or engineers who need to understand the reasons for success or failure of a device and to have key elements of discussion.


Assuntos
Cordas Tendinosas , Valva Mitral , Humanos , Animais , Ovinos , Cães , Suínos , Valva Mitral/anatomia & histologia , Valva Mitral/fisiologia , Valva Mitral/cirurgia , Anatomia Comparada , Cordas Tendinosas/anatomia & histologia , Cordas Tendinosas/fisiologia , Músculos Papilares/anatomia & histologia , Valva Aórtica
3.
Sci Rep ; 9(1): 4677, 2019 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-30886234

RESUMO

In this paper, we propose a very innovative designed system that enables optimal length adjustment during transapical neochordae implantation for mitral valve repair, increasing accuracy and reproducibility of neochordae length adjustment. Also, such a new device allowed real-time measurement and recording of chordae tension, producing original physiological data. To the best of our knowledge, the tension of chordae had never been measured previously as precisely, especially in in vivo human clinical trials. Preliminary experimental data have been collected on 10 selected patients, giving us the opportunity to assess for the first time the tension applied on the chordae implanted in beating human hearts. The final goal of our measuring device is to provide reliable objective intraoperative data to improve the understanding of changes occurring after mitral valve repair (MVR). This novel measuring instrument may bring change in the paradigm of MVR by allowing repair with strong objective and quantitative, instead of qualitative anatomical analysis.


Assuntos
Cordas Tendinosas/cirurgia , Implante de Prótese de Valva Cardíaca , Insuficiência da Valva Mitral/cirurgia , Valva Mitral/cirurgia , Cordas Tendinosas/anatomia & histologia , Desenho de Equipamento , Equipamentos e Provisões , Humanos , Valva Mitral/anatomia & histologia , Reprodutibilidade dos Testes
4.
Acta Biomater ; 85: 241-252, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30579963

RESUMO

BACKGROUND: Healthy function of tricuspid valve (TV) structures is essential to avoid tricuspid regurgitation (TR) and may significantly improve disease prognosis. Mitral valve (MV) structures have been extensively studied, but little is known about the TV and right-sided heart diseases. Therefore, clinical decisions and finite element (FE) simulations often rely heavily on MV data for TV applications, despite fundamentally different mechanical and physiological environments. METHOD/RESULTS: To bridge this gap, we performed a rigorous mechanical, morphological, and microstructural characterization of the MV and TV leaflets and chordae in a porcine model. Planar biaxial testing, uniaxial testing, second harmonic generation imaging and Verhoeff Van Gieson staining were performed. Morphological parameters, tissue moduli, extensibility, and anisotropy were quantified and compared. No major differences in leaflet mechanics or structure were found between TV and MV; chordal mechanics, morphology, and structure were found to compensate for anatomical and physiological loading differences between the valves. No differences in chordal mechanics were observed by insertion point within a leaflet; the septal tricuspid leaflet (STL) and posterior mitral leaflet (PML) did not have distinguishable strut chords, and the STL had the shortest chords. Within a valve, chords from septally-located leaflets were more extensible. MV chords were stiffer. CONCLUSIONS: This study presents the first rigorous comparative mechanical and structural dataset of MV and TV structures. Valve type and anatomical location may be stronger predictors of chordal mechanics. Chords from septally-located leaflets differ from each other and from their intravalvular counterparts; they merit special consideration in surgical and computational applications. STATEMENT OF SIGNIFICANCE: A better understanding of the tricuspid valve (TV) and its associated structures is important for making advancements towards the repair of tricuspid regurgitation. Mitral valve structures have been extensively studied, but little is known about the TV and right-sided heart diseases. Clinical decisions and computational simulations often rely heavily on MV data for TV applications, despite fundamentally different environments. We therefore performed a rigorous mechanical, morphological, and microstructural characterization of atrioventricular leaflets and chordae tendineae in a porcine model. Finding that valve type and anatomical location may be strong predictors of chordal mechanics, chords from septally-located leaflets differ from each other and from their intravalvular counterparts; they merit special consideration in surgical and computational applications.


Assuntos
Cordas Tendinosas/anatomia & histologia , Cordas Tendinosas/fisiologia , Valva Mitral/anatomia & histologia , Valva Mitral/fisiologia , Valva Tricúspide/anatomia & histologia , Valva Tricúspide/fisiologia , Animais , Fenômenos Biomecânicos , Modelos Biológicos , Suínos
5.
Eur. j. anat ; 22(6): 509-514, nov. 2018. ilus, tab
Artigo em Inglês | IBECS | ID: ibc-182118

RESUMO

Since cardiovascular diseases are emerging as major causes of morbidity and mortality in the modern era, emphasis is laid on understanding normal as well as variant cardiac anatomy. Moreover, the advancement in diagnostic and therapeutic cardio-invasive techniques have prompted the revision of our existing knowledge and understanding about fine details of atrio-ventricular, valvular and chordo-papillary complexes. This study is an endeavour to establish the morphology of the tricuspid valve and chordo-papillary complex of the right ventricle in north Indian population and to compare it with previously provided data by different researchers. The study was conducted using 52 formalin-fixed adult human hearts. The presence, number, shapes, length, number of additional heads of the papillary muscles were observed. The morphology of the tricuspid valve was also noted. The morphology and morphometry of the tricuspid valve and papillary muscles were defined. Awareness of such information, whether normal or variant, is considered a prerequisite for successful, uncomplicated cardiac surgeries and interventional radiology


No disponible


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Valva Tricúspide/anatomia & histologia , Ventrículos do Coração/anatomia & histologia , Músculos Papilares/anatomia & histologia , Cordas Tendinosas/anatomia & histologia , Dissecação/métodos , Cordas Tendinosas/citologia , Músculos Papilares/citologia , Ventrículos do Coração/citologia
6.
Int Heart J ; 59(5): 959-967, 2018 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-30101845

RESUMO

The degree or nature of functional mitral regurgitation (MR) is not necessarily correlated with the size or function of the left ventricle (LV). We hypothesized that the anatomical structure of the mitral valve (MV) complex might play a role in functional MR in ischemic or nonischemic dilated cardiomyopathy (DCM).The structure of the LV and MV complex in DCM patients (n = 29) was assessed using electrocardiogram-gated 320-slice computed tomography and was compared with that in healthy patients (n = 12). Twenty-five DCM patients with mild or low MR (DCM-lowMR) had markedly greater length, diameter, and sphericity index of the LV and a larger tenting area than the controls. The distance between the papillary muscle (PM) tip and the mitral annular plane was not different between DCM-lowMR and normal hearts despite the greater LV length observed in DCM-lowMR. Furthermore, DCM-lowMR had markedly longer chordae tendineae (DCM-lowMR: 24 [20-26] mm; controls: 14 [13-16] mm; P < 0.01) and larger anterior leaflets (DCM-lowMR: 30 [27-31] mm; controls: 22 [20-24] mm; P < 0.01), thus suggesting the adaptive remodeling of the MV complex. Four DCM patients with moderate-severe MR had unbalanced remodeling, such as excessive LV dilatation, short anterior mitral leaflets, and short chordae tendineae.The development of functional MR might be associated with the remodeling of LV and MV components, such as the PMs, chordae tendineae, or anterior MV leaflets. Detailed anatomical assessments of the LV and MV complex would contribute to the adequate staging of ischemic or nonischemic DCM.


Assuntos
Remodelamento Atrial/fisiologia , Cardiomiopatia Dilatada/diagnóstico por imagem , Cordas Tendinosas/diagnóstico por imagem , Ventrículos do Coração/diagnóstico por imagem , Insuficiência da Valva Mitral/diagnóstico por imagem , Valva Mitral/diagnóstico por imagem , Idoso , Cardiomiopatia Dilatada/classificação , Cardiomiopatia Dilatada/patologia , Cardiomiopatia Dilatada/fisiopatologia , Cordas Tendinosas/anatomia & histologia , Cordas Tendinosas/fisiopatologia , Ecocardiografia/métodos , Eletrocardiografia/métodos , Feminino , Ventrículos do Coração/anatomia & histologia , Ventrículos do Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Valva Mitral/anatomia & histologia , Valva Mitral/fisiopatologia , Insuficiência da Valva Mitral/fisiopatologia , Músculos Papilares/anatomia & histologia , Músculos Papilares/diagnóstico por imagem , Músculos Papilares/fisiopatologia , Estudos Retrospectivos , Tomografia Computadorizada por Raios X
7.
PLoS One ; 13(6): e0198331, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29902273

RESUMO

OBJECTIVES: Functional mitral regurgitation (FMR) is a significant complication of left ventricle (LV) dysfunction associated with poor prognosis and commonly treated by undersized ring annuloplasty. This study aimed to quantitatively simulate the treatment outcomes and mitral valve (MV) biomechanics following ring annulopalsty and papillary muscle relocation (PMR) procedures for a FMR patient. METHODS: We utilized a validated finite element model of the left heart for a patient with severe FMR and LV dilation from our previous study and simulated virtual ring annuloplasty procedures with various sizes of Edwards Classic and GeoForm annuloplasty rings. The model included detailed geometries of the left ventricle, mitral valve, and chordae tendineae, and incorporated age- and gender- matched nonlinear, anisotropic hyperelastic tissue material properties, and simulated chordal tethering at diastole due to LV dilation. RESULTS: Ring annuloplasty with either the Classic or GeoForm ring improved leaflet coaptation and increased the total leaflet closing force while increased posterior mitral leaflet (PML) stresses and strains. Classic rings resulted in larger coaptation forces and areas compared to GeoForm rings. The PMR procedure further improved the leaflet coaptation, decreased the PML stress and strain for both ring shapes and all sizes in this patient model. CONCLUSIONS: This study demonstrated that a rigorously developed patient-specific computational model can provide useful insights into annuloplasty repair techniques for the treatment of FMR patients and could potentially serve as a tool to assist in pre-operative planning for MV repair surgical or interventional procedures.


Assuntos
Cordas Tendinosas/anatomia & histologia , Anuloplastia da Valva Mitral/métodos , Insuficiência da Valva Mitral/cirurgia , Músculos Papilares/cirurgia , Anisotropia , Análise de Elementos Finitos , Próteses Valvulares Cardíacas , Humanos , Modelos Biológicos
8.
Artigo em Inglês | MEDLINE | ID: mdl-27342229

RESUMO

Over the years, three-dimensional models of the mitral valve have generally been organized around a simplified anatomy. Leaflets have been typically modeled as membranes, tethered to discrete chordae typically modeled as one-dimensional, non-linear cables. Yet, recent, high-resolution medical images have revealed that there is no clear boundary between the chordae and the leaflets. In fact, the mitral valve has been revealed to be more of a webbed structure whose architecture is continuous with the chordae and their extensions into the leaflets. Such detailed images can serve as the basis of anatomically accurate, subject-specific models, wherein the entire valve is modeled with solid elements that more faithfully represent the chordae, the leaflets, and the transition between the two. These models have the potential to enhance our understanding of mitral valve mechanics and to re-examine the role of the mitral valve chordae, which heretofore have been considered to be 'invisible' to the fluid and to be of secondary importance to the leaflets. However, these new models also require a rethinking of modeling assumptions. In this study, we examine the conventional practice of loading the leaflets only and not the chordae in order to study the structural response of the mitral valve apparatus. Specifically, we demonstrate that fully resolved 3D models of the mitral valve require a fluid-structure interaction analysis to correctly load the valve even in the case of quasi-static mechanics. While a fluid-structure interaction mode is still more computationally expensive than a structural-only model, we also show that advances in GPU computing have made such models tractable. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Simulação por Computador , Imageamento Tridimensional/métodos , Valva Mitral/anatomia & histologia , Valva Mitral/fisiologia , Modelos Anatômicos , Cordas Tendinosas/anatomia & histologia , Cordas Tendinosas/fisiologia , Humanos
9.
Anat Histol Embryol ; 45(6): 485-489, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27027271

RESUMO

The canine right atrioventricular valve cusps are anchored to papillary muscles by chordae tendineae. During ventricular systole, these tendineae keep the cusps from being pushed into the atrium. While this is the general description for chordae tendineae, several researchers have briefly documented chordae tendineae in animal and human hearts that do not attach to papillary muscles. In the 39 canine hearts examined, atypical chordae tendineae were observed in two hearts. In both dogs, a single stranded chordae tendineae extended from the free edge of the parietal cusp of the right atrioventricular valve to the ventricular free wall. While the discovery of these atypical tendineae provides additional information on canine cardiac anatomy, their presence may also be clinically significant. A review of the veterinary and biomedical literature showed entanglement in normal chordae tendineae can be a complication during cardiac catheterization or pacemaker lead placement. Given this issue with normal chordae tendineae, it seems logical to propose that these atypical tendineae could also cause catheter or pacemaker lead entanglement and therefore warrant further study and documentation.


Assuntos
Cateterismo/veterinária , Cordas Tendinosas/anormalidades , Cordas Tendinosas/anatomia & histologia , Cães/anatomia & histologia , Ventrículos do Coração/anatomia & histologia , Músculos Papilares/anatomia & histologia , Valva Tricúspide/anatomia & histologia , Animais , Feminino , Ventrículos do Coração/anormalidades , Masculino , Marca-Passo Artificial
10.
J Heart Valve Dis ; 25(5): 596-605, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-28238242

RESUMO

BACKGROUND: Tricuspid regurgitation may be a precursor for heart failure, reduced functional capacity, and poor survival. A human compatible experimental model is required to understand the pathophysiology of the tricuspid valve disease as a basis for validating novel tricuspid valve interventions before clinical use. The study aim was to evaluate and compare the tricuspid valve anatomy of porcine and human hearts. METHODS: The anatomy of the tricuspid valve and the surrounding structures that affect the valve during a cardiac cycle were examined in detail in 100 fresh and 19 formalin-fixed porcine hearts obtained from Danish Landrace pigs (body weight 80 kg). All valvular dimensions were compared with human data acquired from literature sources. RESULTS: No difference was seen in the tricuspid annulus circumference between porcine and human hearts (13.0 ± 1.2 cm versus 13.5 ± 1.5 cm; p = NS), or in valve area (5.7 ± 1.6 cm2 versus 5.6 ± 1.0 cm2; p = NS). The majority of chordae types exhibited a larger chordal length and thickness in human hearts compared to porcine hearts. In both species, the anterior papillary muscle (PM) was larger than other PMs in the right ventricle, but muscle length varied greatly (range: 5.2-40.3 mm) and was significantly different in pigs and in humans (12.2 ± 3.2 mm versus 19.2 mm; p <0.001). CONCLUSIONS: The porcine tricuspid valve was determined to be a valid model for preclinical animal studies, despite various anatomic differences being noted between porcine and human hearts.


Assuntos
Modelos Animais de Doenças , Insuficiência da Valva Tricúspide/patologia , Valva Tricúspide/anatomia & histologia , Animais , Cordas Tendinosas/anatomia & histologia , Humanos , Músculos Papilares/anatomia & histologia , Suínos , Valva Tricúspide/fisiopatologia , Insuficiência da Valva Tricúspide/fisiopatologia , Insuficiência da Valva Tricúspide/cirurgia
11.
Proc Inst Mech Eng H ; 230(2): 77-84, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26645804

RESUMO

A number of studies have investigated the morphological and mechanical properties of the chordae tendineae of the mitral valve, providing comparisons between basal, marginal, and strut chordae and between chordae at the anterior and posterior leaflets. This study contributes to the literature by comparing the failure load of the chordae tendineae attached to the three posterior leaflet scallops, the anterolateral scallop (P1), middle scallop (P2), and posteromedial scallop (P3) of the mitral valve. In all, 140 chordae isolated from 23 porcine hearts were tested. First, the cross-sectional diameters of all branches in each chorda were measured using a microscope. Next, after positioning the chorda in a tensile testing machine, a preload of 0.2 N was applied, and the chordal length was measured. Cyclic loading between 0 and 0.3 N, 10 times with a speed of 1.5 mm/s, was conducted, after which the machine travelled at 1.5 mm/s until the chorda broke. We found that P2 chordae were thicker than P1 and P3 chordae and longer than P1 chordae. P2 chordae failed at significantly higher loads than P1 and P3 chordae. For all three types of chordae, almost half of the failures occurred at the chordal branch that was closest to the leaflet.


Assuntos
Cordas Tendinosas/anatomia & histologia , Cordas Tendinosas/fisiologia , Valva Mitral/anatomia & histologia , Valva Mitral/fisiologia , Anatomia Transversal , Animais , Suínos , Resistência à Tração/fisiologia
12.
Anat Sci Int ; 91(2): 143-50, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25677415

RESUMO

The tricuspid valve complex has been studied since the beginning of the twentieth century, and variations in the structural orientation of the tricuspid leaflets has been reported before, as the occurrence of accessory leaflets poses a major problem during surgeries related to the tricuspid valve. In this study, 36 adult formalin-fixed human hearts were analyzed to compare the number, form and size of the tricuspid leaflets. The result shows that in right ventricles, the number of leaflets can vary from the routine three to as many as seven, and the localization of such accessory leaflets of the tricuspid valve differs between specimens. Five leaflet forms were the most common, and the 'typical' form of tricuspid valves with no accessory leaflets was only present in a small percentage of the cases studied. Measurements of the main and accessory leaflets showed that the anterior leaflets were the largest, followed by the inferior leaflets, while the septal and the accessory leaflets were the smallest in size. On the basis of these results, it is suggested that three leaflets of the tricuspid valve are relatively uncommon, with frequent occurrences of accessory leaflets. The multicuspidal form of the tricuspid valve therefore raises concern about understanding the functional and physiological significance of the accessory leaflets.


Assuntos
Variação Anatômica , Valva Tricúspide/anatomia & histologia , Adulto , Idoso , Cadáver , Cordas Tendinosas/anatomia & histologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Músculos Papilares/anatomia & histologia
13.
EuroIntervention ; 10 Suppl U: U106-11, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25256321

RESUMO

Mitral regurgitation is a common valvular heart disease and its prevalence is expected to increase with population ageing. Percutaneous techniques for the treatment of mitral regurgitation are emerging as an alternative therapeutic option. However, the mitral valve is a complex structure, and a comprehensive understanding of the anatomy of the mitral valve apparatus and its surrounding structures is crucial for a correct selection of patients and the success of transcatheter mitral valve interventions.


Assuntos
Procedimentos Endovasculares , Anuloplastia da Valva Mitral , Insuficiência da Valva Mitral/cirurgia , Valva Mitral/anatomia & histologia , Cordas Tendinosas/anatomia & histologia , Implante de Prótese de Valva Cardíaca , Humanos , Valva Mitral/cirurgia , Músculos Papilares/anatomia & histologia
14.
J Mech Behav Biomed Mater ; 30: 186-95, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24316874

RESUMO

This study aimed to characterise viscoelastic properties of different categories of chordae tendineae over a range of frequencies. Dynamic Mechanical Analysis (DMA) was performed using a materials testing machine. Chordae (n=51) were dissected from seven porcine hearts and categorised as basal, marginal, strut or commissural. Chordae were loaded under a sinusoidally varying tensile load at a range of frequencies between 0.5 and 5Hz, both at a standardised load (i.e. same mean load of 4N for all chordae) and under chordal specific loading (i.e. based on in vivo loads for different chordae). Storage modulus and stiffness were frequency-dependent. Loss modulus and stiffness were frequency-independent. Storage and loss moduli, but not stiffness, decreased with chordal diameter. Therefore, strut chordae have the lowest moduli and marginal chordae the highest moduli. The hierarchy of dynamic storage and loss moduli is: marginal, commissural, basal and strut. In conclusion, viscoelastic properties of chordae are dependent on both frequency and chordal type. Future/novel replacement chordal materials should account for frequency and diameter dependent viscoelastic properties of chordae tendineae.


Assuntos
Cordas Tendinosas/anatomia & histologia , Elasticidade , Teste de Materiais , Valva Mitral/anatomia & histologia , Animais , Fenômenos Biomecânicos , Cordas Tendinosas/fisiologia , Humanos , Valva Mitral/fisiologia , Suínos , Resistência à Tração , Viscosidade , Suporte de Carga
15.
Eur Heart J Cardiovasc Imaging ; 14(10): 986-95, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23341146

RESUMO

AIMS: To explore the potentiality of cardiovascular magnetic resonance (CMR) in the quantitative evaluation of mitral valve annulus (MVA) and tricuspid valve annulus (TVA) morphology and dynamics. METHODS AND RESULTS: CMR was performed in 13 normal subjects and 9 patients with mitral (n = 7) or tricuspid regurgitation (n = 2), acquiring cine-images in 18 radial long-axis planes passing through the middle of MVA or TVA. A novel algorithm was used to obtain dynamic three-dimensional (3D) reconstruction of MVA and TVA. Analysis was feasible in all cases, allowing accurate 3D annular reconstruction and tracking. The 3D area increased from systole [MVA, median = 10.0 cm(2) (first quartile = 8.6, third quartile = 11.4); TVA, 11.2 cm(2) (8.8-13.2)] to diastole [MVA, 10.6 cm(2) (9.4, 11.7); TVA, 11.9 cm(2) (9.2-13.5)], with TVA larger than MVA. While the longest diameter showed similar systolic and diastolic values, the shortest diameter elongated from systole [MVA, 30 mm (29-33); TVA, 33 mm (31-36)] to diastole [MVA, 31 mm (29-32); TVA, 36 mm (33-39)]. Also, TVA became more circular than MVA. TVA showed lower peak systolic excursion in the septal [15.9 mm (13.0-18.5)] and anterior regions [17.9 mm (12.2-20.7)] compared with the posterior [21.9 mm (18.6-24.0)] segment. Values in MVA were smaller than in TVA, slightly higher in anterior [11.2 mm (9.5-13.0)] than in posterior [12.4 mm (10.2-14.6)] segments. Valvular regurgitation was associated with enlarged, flattened, and more circular annuli. CONCLUSION: The applied method was feasible and accurate in normal and regurgitant valves, and may potentially have an impact on diagnosis, improvement of surgical techniques and design of annular prostheses.


Assuntos
Imageamento Tridimensional , Imagem Cinética por Ressonância Magnética/métodos , Insuficiência da Valva Mitral/diagnóstico , Valva Mitral/anatomia & histologia , Insuficiência da Valva Tricúspide/diagnóstico , Valva Tricúspide/anatomia & histologia , Adulto , Anuloplastia da Valva Cardíaca/métodos , Estudos de Casos e Controles , Cordas Tendinosas/anatomia & histologia , Cordas Tendinosas/cirurgia , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valva Mitral/patologia , Valva Mitral/cirurgia , Valores de Referência , Índice de Gravidade de Doença , Estatísticas não Paramétricas , Valva Tricúspide/patologia , Valva Tricúspide/cirurgia
16.
Singapore Med J ; 54(1): 44-8, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23338917

RESUMO

INTRODUCTION: Papillary muscle rupture and dysfunction can lead to complications of prolapsed mitral valve and mitral regurgitation. Multiple operative procedures of the papillary muscles, such as resection, repositioning and realignment, are carried out to restore normal physiological function. Therefore, it is important to know both the variations and the normal anatomy of papillary muscles. METHODS: This study was carried out on 116 human cadaveric hearts. The left ventricles were opened along the left border in order to view the papillary muscles. The number, shape, position and pattern of the papillary muscles were observed. RESULTS: In this series, the papillary muscles were mostly found in groups instead of in twos, as is described in standard textbooks. Four different shapes of papillary muscles were identified - conical, broad-apexed, pyramidal and fan-shaped. We also discovered various patterns of papillary muscles. CONCLUSION: No two mitral valve complexes have the same architectural arrangement. Each case seems to be unique. Therefore, it is important for scientists worldwide to study the variations in the mitral valve complex in order to ascertain the reason behind each specific architectural arrangement. This will enable cardiothoracic surgeons to tailor the surgical procedures according to the individual papillary muscle pattern.


Assuntos
Coração/anatomia & histologia , Valva Mitral/patologia , Músculos Papilares/patologia , Adulto , Anatomia/métodos , Cadáver , Cordas Tendinosas/anatomia & histologia , Humanos , Pessoa de Meia-Idade , Insuficiência da Valva Mitral/fisiopatologia , Modelos Anatômicos , Cirurgia Torácica/métodos
17.
J Heart Valve Dis ; 21(4): 433-9, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22953667

RESUMO

BACKGROUND AND AIM OF THE STUDY: Mitral valve chordae tendineae are an essential component for correct functioning of the human heart. The microstructural make-up of the chordae is responsible for their tensile properties, and is seen gradually to change with age. However, little is known of the maturation of chordae tendineae and their microstructure. METHODS: To examine such maturation, structural changes in chordae tendineae were studied in rats at 1, 3, 7, 15 and 30 days of postnatal life, and in adult rats. Differences in the chordae microstructure of each age group were observed using light microscopy. The collagen fibril crimp period was determined using polarized light microscopy. RESULTS: At day 1 after birth the chordae had yet to develop, and the lateral sides of the mitral valve leaflets were completely attached to the papillary muscles. Chordae developed through the formation of gaps in the leaflet tissue. From day 7 on, numerous chordae were seen. As the chordae matured, crimped collagen fibrils were formed and began to align in a longitudinally packed core with increasing density. The collagen fibril crimp period increased significantly with the age of the animal. CONCLUSION: Rat chordae tendineae have yet to develop at postnatal day 1. Morphological development and microstructural maturation of the chordae are not completed until adulthood (>30 days). A further understanding of the development of mitral valve chordae tendineae will provide insight for the use of tissue-engineered chordae in surgical repair.


Assuntos
Cordas Tendinosas/anatomia & histologia , Cordas Tendinosas/crescimento & desenvolvimento , Valva Mitral/anatomia & histologia , Valva Mitral/crescimento & desenvolvimento , Músculos Papilares/anatomia & histologia , Músculos Papilares/crescimento & desenvolvimento , Fatores Etários , Animais , Animais Recém-Nascidos , Cordas Tendinosas/fisiologia , Colágeno/fisiologia , Humanos , Microscopia de Polarização , Valva Mitral/fisiologia , Miofibrilas/fisiologia , Músculos Papilares/fisiologia , Ratos , Ratos Sprague-Dawley , Engenharia Tecidual
18.
Braz. j. morphol. sci ; 29(1): 49-52, Jan.-Mar. 2012. ilus
Artigo em Inglês | LILACS | ID: lil-654225

RESUMO

Forty Santa Ines sheep (Ovis aries Lin.) hearts were examined with the purpose of studying the present types of chordae  tendineae in the left valve complex. The study was performed at the State University of North Fluminense Darcy Ribeiro, Morphology sector of the Agricultural Science Animal Health Center Laboratory. Hearts were initially kept in 10% formalin solution and later dissected to undergo removal and plannifcation of left atrioventricular complex. With the removal of the left atrioventricular complex began the observation and characterization of the cord. After the analysis we observed the presence of eight types of cuspidal chordae tendineae present in the left valve complex, they were classifed as type I, II, III, IV, V, VI, VII and commissural kind.


Assuntos
Animais , Cordas Tendinosas , Coração/anatomia & histologia , Cordas Tendinosas/anatomia & histologia , Coração , Dissecação , Ovinos
19.
Catheter Cardiovasc Interv ; 79(5): 720-5, 2012 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-21953731

RESUMO

OBJECTIVES: The objective of the study was to describe the distribution and determine the predictors of aortic valve annulus diameter (AVAD) in Chinese patients with severe calcific aortic valve stenosis (CAS). BACKGROUND: AVAD in Chinese patients with CAS has not been reported. Predictors of AVAD in patients with CAS are unclear. METHODS: One hundred elderly patients (≥60 years) with severe CAS were included in the study. AVAD in all patients was measured by transthoracic echocardiograph (AVAD-TTE) and in 74 patients of them was measured intra-operatively (AVAD-intra). RESULTS: The intraclass correlation coefficient (ICC) between AVAD-TTE and AVAD-intra was 0.81 (95% CI: 0.72-0.88). The differences between AVAD-TTE and AVAD-intra ranged from -3 to 3 mm and were ≤≤ 2mm in 91.9% (68/74) of patients. The intra-observer ICC for TTE was 0.87 (95% CI: 0.74-0.94). Mean AVAD in the whole population was 21.80 ± 2.09 (17-27) mm. 11% of cases had an AVAD < 20 mm, 78% had an AVAD between 20 and 24 mm, and 11% had an AVAD between 25 and 27 mm. The correlation between AVAD and height (r = 0.476, P < 0.001) was stronger than that between AVAD and weight (r = 0.215, P = 0.034) or body surface area (BSA) (r = 0.358, P < 0.001). Multivariate regression showed that height, sex, and age but not BSA were independent predictors of AVAD (all P < 0.05). CONCLUSION: Most of Chinese patients with CAS can be candidates for transcatheter aortic valve implantation procedure in terms of AVAD, whereas more sizes of prosthetic valves need to be developed. Sex, age, and especially height, but not BAS, are independent predictors of AVAD in patients with CAS.


Assuntos
Estenose da Valva Aórtica/cirurgia , Cateterismo Cardíaco/métodos , Cordas Tendinosas/anatomia & histologia , Implante de Prótese de Valva Cardíaca/métodos , Próteses Valvulares Cardíacas , Desenho de Prótese , Idoso , Idoso de 80 Anos ou mais , Antropometria , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/etnologia , Povo Asiático/genética , Calcinose/fisiopatologia , Cateterismo Cardíaco/efeitos adversos , China , Cordas Tendinosas/diagnóstico por imagem , Estudos de Coortes , Ecocardiografia Doppler/métodos , Ecocardiografia Transesofagiana/métodos , Feminino , Seguimentos , Implante de Prótese de Valva Cardíaca/efeitos adversos , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Determinação de Necessidades de Cuidados de Saúde , Estudos Prospectivos , Medição de Risco , Índice de Gravidade de Doença , Taxa de Sobrevida , Resultado do Tratamento
20.
Am J Vet Res ; 72(9): 1186-92, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21879976

RESUMO

OBJECTIVE: To compare echocardiographic variables of dogs with postmortem anatomic measurements and histologic characteristics of the mitral valve (MV). ANIMALS: 21 cardiologically normal dogs. PROCEDURES: The MV was measured echocardiographically by use of the right parasternal 5-chamber long-axis view. Dogs were euthanized, and anatomic measurements of the MV annulus (MVa) were performed at the level of the left circumflex coronary artery. Mitral valve leaflets (MVLs) and chordae tendineae were measured. Structure of the MVLs was histologically evaluated in 3 segments (proximal, middle, and distal). RESULTS: Echocardiographic measurements of MVL length did not differ significantly from anatomic measurements. A positive correlation was detected between body weight and MVa area. There was a negative correlation between MVa area and the percentage by which the MVL area exceeded the MVa area. Anterior MVLs had a significantly higher number of chordae tendineae than did posterior MVLs. Histologically, layering of MVLs was less preserved in the distal segment, whereas the muscular component and adipose tissue were significantly more diffuse in the proximal and middle segments. CONCLUSIONS AND CLINICAL RELEVANCE: The MV in cardiologically normal dogs had wide anatomic variability. Anatomic measurements of MVL length were correlated with echocardiographic measurements.


Assuntos
Cordas Tendinosas/anatomia & histologia , Cães/anatomia & histologia , Ecocardiografia/métodos , Valva Mitral/anatomia & histologia , Animais , Cordas Tendinosas/diagnóstico por imagem , Ecocardiografia/veterinária , Feminino , Masculino , Valva Mitral/diagnóstico por imagem
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