Broken Heart Strings - Psychological Stress in Cardiac Patients after Chordae Tendineae Rupture

Chordae tendineae rupture is a potentially life-threatening cardiac event often resulting in acute mitral regurgitation with significant haemodynamic dysfunctions that require immediate medical intervention. However, to date, the psychological burden of cardiac patients with chordae tendineae rupture has been starkly neglected. Despite its potentially devastating effects on affected patients' physical health, the potential psychological effects have yet to be described. Moreover, while traumatic conditions within the spectrum of acute coronary syndrome and potentially traumatic cardiological treatment procedures (e.g., defibrillator implantation) have been at the centre of research efforts, neither the relationship of post-traumatic stress disorder, depression, nor anxiety and chordae tendineae rupture has received any attention so far. Hence, although psycho-emotional comorbidities of heart disease have received much attention, little is known about patients’ psychological burden after acute severe mitral regurgitation due to chordae tendineae rupture. This pilot study aimed to assess affected cardiological patients’ psychological burden after acute severe mitral regurgitation due to chordae tendineae rupture in a mixed-method approach. For the monocentric, cross-sectional, non-interventional study presented in this thesis clinical and psychometric data was systematically collected in two cardiological samples (chordae tendineae rupture case study patients and myocardial infraction control study patients) after hospitalisation for a chordae tendineae rupture event or myocardial infraction

Retrospective study of the association between neutering status and changes secondary to degenerative mitral valve disease

Dissertação de Mestrado Integrado em Medicina VeterináriaMyxomatous mitral valve disease is the most common cardiovascular disease reported in dogs. Although many patients may remain asymptomatic, some of them progress to left-sided congestive heart failure and develop clinical signs. Little has yet been published regarding the possible influence of the neutering status on changes secondary to myxomatous mitral valve disease. This study aims to assess a possible correlation between neutering status and myxomatous mitral valve disease. A retrospective study was conducted and included all the cases diagnosed with myxomatous mitral valve disease, consulted at the Cardiology service of the University of Liverpool. To help assess the association between neutering status and cardiac remodelling, dogs were categorized into four groups: FE (female entire), FN (female neutered), ME (male entire) and MN (male neutered). Retrospective review of echocardiographic data, signalment, and underlying diseases were performed. Echocardiographic measurements were made through offline analysis. Echocardiographic measurements were then compared between groups. Five hundred and eighty-two dogs (n = 582) were included: female entire (n = 24), female neutered (n = 235), male entire (n = 115) and male neutered (n = 208). Left ventricular internal diameter at end diastole (LVIDd), left atrial dimension to the aortic root diameter (LA:Ao) and left atrium maximal dimension to the aortic root dimension (LAmax:Ao) were significantly different between ME and MN, with ME dogs presenting higher mean values for LVIDd and higher median LA:Ao and LAmax:Ao measurements. Left ventricular internal diameter at end systole (LVIDs) was not significantly different between ME and MN. There were no significant differences between FE and FN groups. This study shows that neutering status may influence the development of myxomatous mitral valve disease in male dogs and that entire male dogs could be at higher risk of developing cardiac remodelling secondary to myxomatous mitral valve disease. On the other hand, neutering status doesn’t seem to have an influence on disease progression in female dogs.RESUMO - Estudo retrospetivo da associação entre a esterilização e alterações secundárias à doença mixomatosa da válvula mitral - A doença mixomatosa da válvula mitral é a doença cardiovascular mais prevalente em cães. Apesar da maior parte dos pacientes permanecerem assintomáticos, alguns podem progredir para insuficiência cardíaca esquerda e desenvolver sinais clínicos. Até hoje, existem poucas publicações sobre o possível efeito que a esterilização possa ter no desenvolvimento da doença mixomatosa da válvula mitral. O objetivo deste estudo é avaliar se existe de facto uma relação entre a esterilização e a doença mixomatosa da válvula mitral. Foi realizado um estudo retrospetivo que incluiu todos os casos diagnosticados com doença mixomatosa da válvula mitral consultados no serviço de Cardiologia da Universidade de Liverpool. Para avaliar a relação entre a esterilização e a presença de remodelação cardíaca, os cães foram categorizados em quatro grupos: FE (fêmeas inteiras), FN (fêmeas esterilizadas), ME (machos inteiros) e MN (machos castrados). A história pregressa e os dados ecocardiográficos dos animais foram revistos retrospetivamente e as medidas ecocardiográficas foram obtidas por medição offline. Estas medições foram depois comparadas entre os diferentes grupos. Quinhentos e oitenta e dois cães (n = 582) foram incluídos: fêmeas inteiras (n = 24), fêmeas esterilizadas (n = 235), machos inteiros (n = 115) e machos castrados (n = 208). Nos resultados obtidos, o diâmetro interno do ventrículo esquerdo no final da diástole (LVIDd), o rácio átrio esquerdo-aorta (LA:Ao) e o rácio diâmetro máximo do átrio esquerdo-aorta (LAmax:Ao) foram estatisticamente significativos entre machos inteiros e machos castrados. Os machos inteiros apresentaram não só um LVIDd médio superior, como também uma mediana de LA:Ao e LAmax:Ao superior aos machos castrados. Ao mesmo tempo, o diâmetro interno do ventrículo esquerdo no final da sístole (LVIDs) não mostrou ser estatisticamente significativo entre machos inteiros e machos castrados e nenhum dos parâmetros ecocardiográficos anteriormente referidos revelou ser estatisticamente significativo entre fêmeas inteiras e fêmeas esterilizadas. Este estudo demonstra que a esterilização poderá influenciar o desenvolvimento da doença mixomatosa da válvula mitral e que os cães machos inteiros poderão apresentar um maior risco de desenvolver remodelação cardíaca secundária a esta doença. No entanto, a esterilização não aparenta influenciar a progressão desta doença em cadelas.N/

Pressure Acquisition System for In Vitro Mitral Valve Analysis

In vitro testing of the mitral valve chordae tendineae is utilized to aid in the understanding of the stresses that occur in vivo and improve upon surgical solutions that exist for mitral valve repair. This project aimed to design the water control system for a left heart simulation chamber, as well as the pressure acquisition inside the chamber. A solenoid valve was utilized to control the water supply to the tank and was powered utilizing National Instruments software. National Instruments hardware and software was also used with the pressure transducer in order to obtain pressure readings from the chamber. The system was able to be fully controlled using LabVIEW and a pressure trend line was acquired. Future work will focus on developing a way to obtain more precise pressure measurements and automating the solenoid valve to shut off the water supply once physiological pressure has been met inside the chamber

Estudo da resistência à tração das cordas da valva mitral

OBJECTIVE: To determinate the extension and the resistance of the primary mitral valve chordae tendineae when submitted to traction. The importance of keeping the integrity of papillary muscle, chordae tendineae, and mitral valve cuspid when the replacement of this valve occurs is clear, but the knowledge of the maximum resistance that a primary tendinea chorda can withstand is not known. METHODS: Eight hearts were dissected, and one hundred and thirty two primary human chordae tendineae were measured (length and thickness) and submitted to traction under controlled conditions so that the absolute resistance, resistance relative to thickness (relative resistance), and elongation could be measured. RESULTS: The correlation between the elongation at the moment of rupture and the thickness was equal to 1.54 + 17.02 x thickness (P = 0.026); and to absolute resistance was equal to 0.95 + 1.42 x resistance (P < 0.001); and to the resistance relative to thickness (relative resistance) was equal to 1.95 + 0.08 x relative resistance (P = 0.009). The correlation between the absolute resistance and the thickness was equal to 0.26 + 14.53 x thickness (P < 0.001). CONCLUSION: The resistance of primary mitral valve chordae tendineae is associated with its thickness and elongation at the moment of rupture, but is not associated with the length. The elongation at the moment of rupture shows a relationship with the resistance relative to thickness (relative resistance) and with the thickness of the primary chordae tendineae, but not with the length of the chordae tendineae.OBJETIVO: Determinar o alongamento e a resistência à tração das cordas tendíneas primárias humanas da valva mitral cardíaca. Sabe-se da importância de se manter a integridade do músculo papilar, corda tendínea e cúspide da valva mitral, quando da substituição desta valva, mas não se tem conhecimento da resistência máxima que uma corda tendínea primaria pode sofrer resistência máxima que uma corda tendínea apresenta. MÉTODO: Foram dissecados 8 corações que permitiram a tração de cento e trinta e duas cordas tendíneas primárias humanas. Foram dissecados 8 corações que permitiram a tração de cento e trinta e duas cordas tendíneas primárias humanas, as quais foram medidas (comprimento e espessura) e submetidas a trações em condições controladas, e assim a resistência absoluta, a resistência relativa a espessura (resistência relativa) e o alongamento puderam ser medidos. RESULTADOS: A correlação entre alongamento no momento da ruptura e espessura foi igual a 1,54 + 17,02*espessura (p=0,026); e à resistência absoluta foi igual a 0,95 + 1,42*resistência (

Mechanics of the tricuspid valve: from clinical diagnosis/treatment, in vivo and in vitro investigations, to patient-specific biomechanical modeling

Proper tricuspid valve (TV) function is essential to unidirectional blood flow through the right side of the heart. Alterations to the tricuspid valvular components, such as the TV annulus, may lead to functional tricuspid regurgitation (FTR), where the valve is unable to prevent undesired backflow of blood from the right ventricle into the right atrium during systole. Various treatment options are currently available for FTR; however, research for the tricuspid heart valve, functional tricuspid regurgitation, and the relevant treatment methodologies are limited due to the pervasive expectation among cardiac surgeons and cardiologists that FTR will naturally regress after repair of left-sided heart valve lesions. Recent studies have focused on (i) understanding the function of the TV and the initiation or progression of FTR using both in-vivo and in-vitro methods, (ii) quantifying the biomechanical properties of the tricuspid valve apparatus as well as its surrounding heart tissue, and (iii) performing computational modeling of the TV to provide new insight into its biomechanical and physiological function. This review paper focuses on these advances and summarizes recent research relevant to the TV within the scope of FTR. Moreover, this review also provides future perspectives and extensions critical to enhancing the current understanding of the functioning and remodeling tricuspid valve in both the healthy and pathophysiological states

Collagen birefringence assessment in heart chordae tendineae through PS-OCT

Degenerative mitral regurgitation is a serious and frequent human heart valve disease. Malfunctioning of this valve brings the left-sided heart through a significant increase of pressure and volume overload. Severe degenerative mitral incompetence generally requires surgical repair or valve replacement with a bioprosthesis or mechanical heart valve. Degenerative disease affects the leaflets or/and the chordae tendineae, which link both leaflets to the papillary muscles. During mitral valve surgical repair, reconstruction of the valve leaflets, annulus and chordae are provided to prevent postoperative recurrence of valve regurgitation. The operative evaluation of the diseased and apparently normal chordae tendineae mainly depends of the surgeon´s experience, without any other objective diagnosis tool. In this work, PS-OCT (Polarization Sensitive-Optical Coherence Tomography) is applied for the first time to evaluate the pathological condition of human chordae coming from the mitral valve. It consists on a prospective study to test the viability of this technique for the evaluation of the collagen core of chords. This core presents a strong birefringence due to the longitudinal and organized arrangement of its collagen bundles. Different densities and organizations of the collagen core translate into different birefringence indicators whose measurement become an objective marker of the core structure. Ex-vivo mitral degenerative chordae tendineae have been analyzed with PS-OCT. Intensity OCT is used to obtain complementary morphological information of the chords. Birefringence results correlate with the previously reported values for human tendinous tissue.The authors thank the “Ministerio de Economía, Industria y Competitividad” (MINECO) for their support in this work under projects DA2TOI (FIS2010-19860), SENSA (TEC2016-76021-C2-2-R), the “Instituto de Salud Carlos III” (ISCIII) through projects FUSIODERM (DTS15/00238) and CIBERBBN and the co-financed by FEDER funds

A finite strain nonlinear human mitral valve model with fluid structure interaction

A simulated human mitral valve under a physiological pressure loading is developed using a hybrid finite element immersed boundary method, which incorporates experimentally based constitutive laws in a three-dimensional fluid-structure interaction framework. A transversely isotropic material constitutive model is used for characterizing the mechanical behaviour of the mitral valve tissue based on recent mechanical tests of healthy human mitral leaflets. Our results show good agreement, in terms of the flow rate and the closing and opening configurations, with the measurements from the magnetic resonance images. The stresses in the anterior leaflet are found to be higher than those in the posterior leaflet, and concentrated around the annulus trigons and free edges of the valve leaflets. Those areas are located where the leaflet has the highest curvature. Effects of the chordae tendineae in the material model are studied and the results show that these chordae play an important role in providing a secondary orifice for the flow when valve opens. Although there are some discrepancies to be overcome in future works, our simulations show that the developed computational model is promising in mimicking the in vivo mitral valve dynamics and providing important information that are not obtainable by in vivo measurements. This article is protected by copyright. All rights reserved

Mitral insufficiency due to ruptured chordae tendineae

The clinical features in six patients with mitral insufficiency due to chordae tendineae have been. The patients in whom the etiology was not known did not become symptomatic till they were past 40, although a murmur had been present for several years. Pulmonary edema or paroxysmal nocturnal dyspnea were the initial symptoms in a number of these patients, preceding the more usual shortness of breath with exertion. The auscultatory and phonocardiographic features are specific. On fluoroscopy readily recognizable paradoxical pulsation of the left atrium was present in some of them. At cardiac catheterization a tall left atrial “v” wave with peak pressure as high as or higher than the peak pressure in the pulmonary artery was constantly found. In a patient with mitral insufficiency where the murmur is harsh and accompanied by a thrill in the fourth intercostal space near the left sternal border and in whom an ejection type systolic murmur is heard unaccompanied by the slow rising pulse of aortic stenosis, the possibility of mitral insufficiency due to ruptured chordae tendineae should be considered