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1.
Cardiol Young ; : 1-6, 2024 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-39376080

RESUMO

INTRODUCTION: Bicuspid aortic valve is the most common CHD and commonly associated with activity restrictions that may lead to a sedentary lifestyle known to increase obesity risk. It is unknown whether obesity is associated with changes in aortic dimensions or aortic valve function in young people with bicuspid aortic valve. This study investigates whether overweight and obese children with bicuspid aortic valve have worse aortic valve function or increased aortic dimensions compared to healthy weight children with bicuspid aortic valve. METHODS: This was a single centre retrospective cohort study comprised of patients 5 to 25 years old with a diagnosis of bicuspid aortic valve between 1 January, 2019 and 31 December, 2020. Patients were classified as healthy weight or overweight/obese. Values for aortic dimensions as well as peak and mean aortic valve gradients were obtained from echocardiogram reports. RESULTS: About 251 patients were analysed. Demographics were similar between groups. When indexed to height, the aortic valve annulus (1.28 ± 0.14 vs. 1.34 ± 0.15, p = 0.001) and sinotubular junctions (1.44 ± 0.21 vs. 1.49 ± 0.24, p = 0.038) were larger in the overweight/obese group, with no differences in aortic root or ascending aorta sizes. The obese/overweight group had a higher peak aortic valve gradient (23.03 ± 1.64 mmHg vs. 16.17 ± 1.55 mmHg, p = 0.003) compared to the healthy weight group. CONCLUSION: Healthy weight patients did not have larger aortic dimensions compared to the overweight/obese patients. There was evidence of worsening aortic valve stenosis in overweight/obese patients compared to those at a healthy weight.

2.
Pacing Clin Electrophysiol ; 46(12): 1455-1464, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37957879

RESUMO

BACKGROUND: Leadless pacemakers (PMs) were recently introduced to overcome lead-related complications. They showed high safety and efficacy profiles. Prospective studies assessing long-term safety on cardiac structures are still missing. OBJECTIVE: The purpose of this study was to compare the mechanical impact of Micra with conventional PM on heart function. METHODS: We conducted a non-inferiority trial in patients with an indication for single chamber ventricular pacing. Patients were 1:1 randomized to undergo implantation of either Micra or conventional monochamber ventricular pacemaker (PM). Patients underwent echocardiography at baseline, 6 and 12 months after implantation. Analysis included left ventricular ejection fraction (LVEF), global longitudinal strain (GLS) and valve function. N-terminal-pro hormone B-type natriuretic peptide (NT-pro-BNP) levels were measured at baseline and 12 months. RESULTS: Fifty-one patients (27 in Micra group and 24 in conventional group) were included. Baseline characteristics were similar for both groups. At 12 months, (1) the left ventricular function as assessed by LVEF and GLS worsened similarly in both groups (∆LVEF -10 ± 7.3% and ∆GLS +5.7 ± 6.4 in Micra group vs. -13.4 ± 9.9% and +5.2 ± 3.2 in conventional group) (p = 0.218 and 0.778, respectively), (2) the severity of tricuspid valve regurgitation was significantly lower with Micra than conventional pacing (p = 0.009) and (3) median NT-pro-BNP was lower in Micra group (970 pg/dL in Micra group versus 1394 pg/dL in conventional group, p = 0.041). CONCLUSION: Micra is non inferior to conventional PMs concerning the evolution of left ventricular function at 12-month follow-up. Our data suggest that Micra has a comparable mechanical impact on the ventricular systolic function but resulted in less valvular dysfunction.


Assuntos
Marca-Passo Artificial , Humanos , Estimulação Cardíaca Artificial/métodos , Coração , Estudos Prospectivos , Volume Sistólico , Resultado do Tratamento , Função Ventricular Esquerda
3.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 39(2): 329-338, 2022 Apr 25.
Artigo em Chinês | MEDLINE | ID: mdl-35523554

RESUMO

The implantation of biventricular assist device (BiVAD) is more challenging than that of left ventricular assist device for the interaction in the process of multiple input and output. Besides, ventricular assist device (VAD) often runs in constant speed (CS) mode in clinical use and thus BiVAD also faces the problems of low pulsation and imbalance of blood volume between systemic circulation and pulmonary circulation. In this paper, a delay assist mode for a VAD by shortening the support time of VAD was put forward. Then, the effect of the delay mode on cardiac output, pulsation and the function of the aortic valve was observed by numerical method and the rules of hemodynamics were revealed. The research showed that compared with VAD supported in CS mode, the VAD using delay mode in systolic and diastolic period proposed in this paper could meet the demand of cardiac output perfusion and restore the function of the arterial valves. The open ratio of aortic valve (AV) and pulmonary valve (PV) increased with the time set in delay mode, and the blood through the AV/PV helped to balance the left and the right cardiac volume. Besides, delay mode also improved the pulsation index of arterial blood flow, which is conducive to the recovery of the ventricular pulse function of patients.


Assuntos
Sistema Cardiovascular , Insuficiência Cardíaca , Coração Auxiliar , Diástole , Frequência Cardíaca , Hemodinâmica , Humanos , Modelos Cardiovasculares
4.
Int Heart J ; 62(1): 95-103, 2021 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-33455980

RESUMO

Enlargement of the mitral valve (MV) has gained attention as a compensatory mechanism for functional mitral regurgitation (FMR). We aimed to determine if MV leaflet area is associated with MV coaptation-zone area and identify the clinical factors associated with MV leaflet size and coaptation-zone area in patients with normal left ventricle (LV) systolic function and size using real-time 3D echocardiography (RT3DE).We performed RT3DE in 135 patients with normal LV size and ejection fraction. MV leaflet and coaptation-zone areas were measured using custom 3D software. The clinical factors associated with MV leaflet and coaptation-zone areas were evaluated using univariate and multivariate linear regression analyses.There was a significant relationship between MV leaflet and coaptation-zone areas (r = 0.499, P < 0.001). MV leaflet area was strongly associated with body surface area (BSA) (r = 0.905, P < 0.001) rather than LV size and age. MV leaflet area/BSA was independently associated with male gender (P = 0.002), lower diastolic blood pressure (P = 0.042), and LV end-diastolic volume (LVEDV) index (P = 0.048); MV coaptation-zone area/BSA was independently associated with lower LVEDV index (P = 0.01).In patients with normal LV systolic function and size, MV leaflet size has a significant impact on competent MV coaptation. MV leaflet area might be intrinsically determined by body size rather than age and LV size, and the MV leaflet area/BSA is relatively constant. On the other hand, some clinical factors might also influence MV leaflet and coaptation-zone area.


Assuntos
Ventrículos do Coração/diagnóstico por imagem , Insuficiência da Valva Mitral/fisiopatologia , Valva Mitral/diagnóstico por imagem , Função Ventricular Esquerda/fisiologia , Idoso , Pressão Sanguínea/fisiologia , Ecocardiografia Tridimensional/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Fatores Sexuais , Volume Sistólico/fisiologia , Sístole
5.
J Physiol ; 598(12): 2297-2310, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32267537

RESUMO

KEY POINTS: Lymphatic valve defects are one of the major causes of lymph transport dysfunction; however, there are no accessible methods for quantitatively assessing valve function. This report describes a novel technique for quantifying lymphatic valve back-leak. Postnatal endothelial-specific deletion of connexin 43 (Cx43) in connexin 37 null (Cx37-/- ) mice results in rapid regression of valve leaflets and severe valve dysfunction. This method can also be used for assessing the function of venous and lymphatic valves from various species, including humans. ABSTRACT: The lymphatic system relies on robust, spontaneous contractions of collecting lymphatic vessels and one-way secondary lymphatic valves to efficiently move lymph forward. Secondary valves prevent reflux and allow for the generation of propulsive pressure during each contraction cycle. Lymphatic valve defects are one of the major causes of lymph transport dysfunction. Genetic mutations in multiple genes have been associated with the development of primary lymphoedema in humans; and many of the same mutations in mice result in valve defects that subsequently lead to chylous ascites or chylothorax. At present the only experimental technique for the quantitative assessment of lymphatic valve function utilizes the servo-null micropressure system, which is highly accurate and precise, but relatively inaccessible and difficult to use. We developed a novel, simplified alternative method for quantifying valve function and determining the degree of pressure back-leak through an intact valve in pressurized, single-valve segments of isolated lymphatic vessels. With this diameter-based method, the competence of each lymphatic valve is challenged over a physiological range of pressures (e.g. 0.5-10cmH2 O) and pressure back-leak is extrapolated from calibrated, pressure-driven changes in diameter upstream from the valve. Using mesenteric lymphatic vessels from C57BL/6J, Ub-CreERT2 ;Rasa1fx/fx , Foxc2Cre/+ , Lyve1-Cre;Cx43fx/fx , and Prox1-CreERT2 ;Cx43fx/fx ;Cx37-/- mice, we tested our method on lymphatic valves displaying a wide range of dysfunction, from fully competent to completely incompetent. Our results were validated by simultaneous direct measurement of pressure back-leak using a servo-null micropressure system. Our diameter-based technique can be used to quantify valve function in isolated lymphatic valves from a variety of species. This method also revealed that haplodeficiency in Foxc2 (Foxc2Cre/+ ) is not sufficient to cause significant valve dysfunction; however, postnatal endothelial-specific deletion of Cx43 in Cx37-/- mice results in rapid regression of valve leaflets and severe valve dysfunction.


Assuntos
Vasos Linfáticos , Linfedema , Animais , Conexina 43/genética , Conexinas , Linfedema/genética , Camundongos , Camundongos Endogâmicos C57BL
6.
Cardiology ; 145(7): 439-445, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32454507

RESUMO

BACKGROUND: After aortic valve replacement (AVR), suspected prosthetic valve dysfunction (mechanical or biological) may arise based on echocardiographic transvalvular velocities and gradients, leading to reoperative surgical intervention being considered. Our experience has found that 4-dimensional (space and time) image reconstruction of ECG-gated computed tomography, termed cine-CT, may be helpful in such cases. We review and illustrate our experience. METHODS: Twenty-seven AVR patients operated previously by a single surgeon (who performs >100 AVRs/year) were referred for repeat evaluation of suspected aortic stenosis (AS) based on elevated transvalvular velocities and gradients. The patients were fully evaluated by cine-CT. RESULTS: In all but 2 cases, the cine-CT strikingly and visually confirmed normal leaflet function and excursion, with no valve thrombosis, restriction by pannus, or obstruction by clot. In only 2 cases did cine-CT reveal decreased mechanical valve leaflet excursion. Repeat surgery was required in only 1 case while all other patients continued clinically without cardiac events. CONCLUSIONS: Echocardiography is an extraordinarily useful tool for the evaluation of prosthetic valve function. Increased pressure recovery beyond the valve and other factors may occasionally lead to exaggerated gradients. Cine-CT is emerging as an extremely valuable tool for further evaluation of suspected prosthetic valve AS. Our experience has been extremely helpful, as is shown in the dramatically reassuring images.


Assuntos
Estenose da Valva Aórtica/diagnóstico por imagem , Valva Aórtica/diagnóstico por imagem , Próteses Valvulares Cardíacas/efeitos adversos , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/cirurgia , Ecocardiografia Doppler , Feminino , Implante de Prótese de Valva Cardíaca , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Reoperação , Sensibilidade e Especificidade , Adulto Jovem
7.
Acta Cardiol Sin ; 36(4): 360-366, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32675928

RESUMO

BACKGROUND: The aim of this study was to investigate the efficiency of tricuspid valve detachment (TVD) during the surgical treatment of perimembranous ventricular septal defects (VSDs) and to compare the early and mid-term results to patients without TVD in terms of tricuspid insufficiency. METHODS: A total of 170 patients who had undergone surgical closure of perimembranous VSDs between November 2012 and January 2019 were included in this study, of whom 50 had an additional TVD procedure during the surgery. All patients were examined by transthoracic echocardiography before and after the operation with regular intervals, and the tricuspid valve function was then evaluated. RESULTS: There was no significant difference between subgroups with an unchanging degree of TVR, however, the result was also similar among those who had a decreased degree of TVR at any level (p = 0.271, p = 0.451). At the end of the study, all patients were in New York Heart Association class I. CONCLUSIONS: We suggest that, in appropriate patients, VSD closure can be safely performed with an additional TVD application through an incision of the septal leaflet of the tricuspid valve without impairing the valve function or reducing the growth potential of the valve at midterm follow-up.

9.
Curr Probl Cardiol ; 49(6): 102534, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38521294

RESUMO

The following letter presents an answer of a comment of our work titled "Ross procedure: valve function, clinical outcomes and predictors after 25 years' follow-up," recently published in your journal by Rangwala et al.1 As our colleagues point out, the Ross procedure has excellent survival rates but a significant risk of valve dysfunction and therefore reintervention at follow-up. Although the survival advantage with the Ross procedure appears to be consistent compared with mechanical valve substitutes, this benefit is not as clear compared with biological valve substitutes. However, biological valve substitutes also have significant reintervention rates during follow-up. The different surgical modifications of the Ross procedure have not clearly demonstrated better results in follow-up in terms of autograft reintervention. This procedure can be performed in a medium-volume center with good results as long as adequate patient selection and adequate surgical training are carried out.


Assuntos
Valva Aórtica , Humanos , Resultado do Tratamento , Valva Aórtica/cirurgia , Implante de Prótese de Valva Cardíaca/métodos , Valva Pulmonar/cirurgia , Valva Pulmonar/transplante , Próteses Valvulares Cardíacas , Seguimentos , Bioprótese , Procedimentos Cirúrgicos Cardíacos/métodos , Reoperação/estatística & dados numéricos , Doenças das Valvas Cardíacas/cirurgia
10.
Curr Probl Cardiol ; 49(5): 102487, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38417472

RESUMO

The following letter presents a critique of the study titled "Ross procedure: valve function, clinical outcomes and predictors after 25 years' follow-up," recently published in your esteemed journal. This study provides a comprehensive analysis of the long-term outcomes of the Ross procedure, focusing on survival rates and incidence of valve dysfunction over a 25-year period. Despite revealing excellent overall survival rates and promising outcomes in pediatric patients, concerns regarding valvular failure and reintervention are underscored. While acknowledging limitations, such as sample size and observational biases, this study highlights the significance of surgeon experience in mitigating adverse outcomes. This critique emphasizes the study's contribution to understanding the efficacy and challenges of the Ross procedure, advocating further research to optimize patient outcomes.


Assuntos
Valva Aórtica , Implante de Prótese de Valva Cardíaca , Criança , Humanos , Valva Aórtica/cirurgia , Seguimentos , Implante de Prótese de Valva Cardíaca/efeitos adversos , Incidência , Reoperação , Fatores de Risco , Resultado do Tratamento
11.
JACC Cardiovasc Interv ; 17(17): 2011-2022, 2024 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-39260959

RESUMO

BACKGROUND: Asymmetrical expansion of transcatheter heart valves (THVs), manifesting as stent frame deformation, is an occasional fluoroscopic finding in transcatheter aortic valve replacement (TAVR). OBJECTIVES: The aim of this study was to investigate the impact of asymmetrical expansion of balloon-expandable THVs on hemodynamic valve performance and clinical outcomes. METHODS: In a prospective registry, TAVR asymmetry index was measured using freeze-frame fluoroscopic images and was defined as the ratio of THV heights: [(longer height/shorter height) - 1] × 100. THV hemodynamic performance was measured using echocardiography before hospital discharge. Impaired hemodynamic valve performance was defined as a mean residual THV gradient ≥20 mm Hg and/or moderate or greater paravalvular regurgitation. RESULTS: Among 1,216 patients undergoing transfemoral TAVR for native severe aortic valve stenosis with contemporary balloon-expandable THVs between February 2014 and June 2022, asymmetry index was an excellent predictor of impaired hemodynamic valve performance (area under the receiver-operating characteristic curve: 0.88; 95% CI: 0.84-0.92; P < 0.001). The optimal asymmetry index threshold for predicting impaired THV performance was >5.5% (sensitivity 77%, specificity 86%) and occurred in 17% of patients. Higher asymmetry index, as a continuous variable, was associated with impaired hemodynamic valve performance independent of total aortic valve calcium, bicuspid anatomy, balloon-expandable valve prosthesis type or size, and Society of Thoracic Surgeons Predicted Risk of Mortality score (OR: 1.37; 95% CI: 1.29-1.46; P < 0.001). High TAVR asymmetry index was not associated with all-cause mortality during a median of 376 days of follow-up (HR: 1.00; 95% CI: 0.71-1.41; P = 0.989). CONCLUSIONS: Asymmetrical expansion of balloon-expandable THVs was associated with impaired hemodynamic valve performance but not with clinical outcomes.


Assuntos
Estenose da Valva Aórtica , Valva Aórtica , Valvuloplastia com Balão , Próteses Valvulares Cardíacas , Hemodinâmica , Desenho de Prótese , Sistema de Registros , Substituição da Valva Aórtica Transcateter , Humanos , Substituição da Valva Aórtica Transcateter/efeitos adversos , Substituição da Valva Aórtica Transcateter/instrumentação , Substituição da Valva Aórtica Transcateter/mortalidade , Masculino , Feminino , Estenose da Valva Aórtica/fisiopatologia , Estenose da Valva Aórtica/cirurgia , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/mortalidade , Idoso de 80 Anos ou mais , Valva Aórtica/fisiopatologia , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/cirurgia , Resultado do Tratamento , Idoso , Fatores de Risco , Fatores de Tempo , Estudos Prospectivos , Índice de Gravidade de Doença , Recuperação de Função Fisiológica , Insuficiência da Valva Aórtica/fisiopatologia , Insuficiência da Valva Aórtica/diagnóstico por imagem , Insuficiência da Valva Aórtica/etiologia
12.
Matrix Biol ; 126: 1-13, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38185344

RESUMO

OBJECTIVE: Mouse models of Marfan syndrome (MFS) with Fibrillin 1 (Fbn1) variant C1041G exhibit cardiovascular abnormalities, including myxomatous valve disease (MVD) and aortic aneurism, with structural extracellular matrix (ECM) dysregulation. In this study, we examine the structure-function-mechanics relations of the mitral valve related to specific transitions in ECM composition and organization in progressive MVD in MFS mice from Postnatal day (P)7 to 1 year-of-age. APPROACH AND RESULTS: Mechanistic links between mechanical forces and biological changes in MVD progression were examined in Fbn1C1041G/+ MFS mice. By echocardiography, mitral valve dysfunction is prevalent at 2 months with a decrease in cardiac function at 6 months, followed by a preserved cardiac function at 12 months. Mitral valve (MV) regurgitation occurs in a subset of mice at 2-6 months, while progressive dilatation of the aorta occurs from 2 to 12 months. Mitral valve tissue mechanical assessments using a uniaxial Permeabilizable Fiber System demonstrate decreased stiffness of MFS MVs at all stages. Histological and microscopic analysis of ECM content, structure, and fiber orientation demonstrate that alterations in ECM mechanics, composition, and organization precede functional abnormalities in Fbn1C1041G/+MFS MVs. At 2 months, ECM abnormalities are detected with an increase in proteoglycans and decreased stiffness of the mitral valve. By 6-12 months, collagen fiber remodeling is increased with abnormal fiber organization in MFS mitral valve leaflets. At the same time, matrifibrocyte gene expression characteristic of collagen-rich connective tissue is increased, as detected by RNA in situ hybridization and qPCR. Together, these studies demonstrate early prevalence of proteoglycans at 2 months followed by upregulation of collagen structure and organization with age in MVs of MFS mice. CONCLUSIONS: Altogether, our data indicate dynamic regulation of mitral valve structure, tissue mechanics, and function that reflect changes in ECM composition, organization, and gene expression in progressive MVD. Notably, increased collagen fiber organization and orientation, potentially dependent on increased matrifibrocyte cell activity, is apparent with altered mitral valve mechanics and function in aging MFS mice.


Assuntos
Síndrome de Marfan , Camundongos , Animais , Síndrome de Marfan/genética , Síndrome de Marfan/patologia , Valva Mitral/metabolismo , Valva Mitral/patologia , Matriz Extracelular/metabolismo , Fibrilina-1/genética , Fibrilina-1/metabolismo , Colágeno/metabolismo , Proteoglicanas/metabolismo
13.
Front Cell Dev Biol ; 12: 1331291, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38450249

RESUMO

Introduction: The bileaflet valves found in collecting lymphatic vessels and some veins are essential for maintaining a unidirectional flow, which is important for lymphatic and venous function. Under an adverse pressure gradient, the two leaflets tightly overlap to prevent backflow. Valves are proposed to share four main stages of development, based on images obtained from randomly oriented valves in fixed mouse embryos, with the best structural views obtained from larger venous valves. It is not known at what stage lymphatic valves (LVs) become functional (e.g., able to oppose backflow), although a requirement for stage 4 is presumed. Methods: To gain an insight into this sequence of events for LVs, we used Prox1CreER T2 :Foxo1 fl/fl mice and Foxc2CreER T2 :Foxo1 fl/fl mouse models, in which deletion of the valve repressor factor Foxo1 promotes the development of new LVs in adult lymphatic vessels. Both strains also contained a Prox1eGFP reporter to image the lymphatic endothelium. Mesenteric collecting lymphatic vessels were dissected, cannulated, and pressurized for ex vivo tests of valve function. LVs at various stages (1-4 and intermediate) were identified in multi-valve segments, which were subsequently shortened to perform the backleak test on single valves. The GFP signal was then imaged at high magnification using a confocal microscope. Z-stack reconstructions enabled 1:1 comparisons of LV morphology with a quantitative measurement of back leak. Results: As expected, LVs of stages 1-3 were completely leaky in response to outflow pressure elevation. Stage 4 valves were generally not leaky, but valve integrity depended on the Cre line used to induce new valve formation. A high percentage of valves at leaflet an intermediate stage (3.5), in which there was an insertion of a second commissure, but without proper luminal alignment, effectively resisted back leak when the outflow pressure was increased. Discussion: Our findings represent the first 3D images of developing lymphatic valves and indicate that valves become competent between stages 3 and 4 of development.

14.
ArXiv ; 2023 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-36798457

RESUMO

Advances in three-dimensional imaging provide the ability to construct and analyze finite element (FE) models to evaluate the biomechanical behavior and function of atrioventricular valves. However, while obtaining patient-specific valve geometry is now possible, non-invasive measurement of patient-specific leaflet material properties remains nearly impossible. Both valve geometry and tissue properties play a significant role in governing valve dynamics, leading to the central question of whether clinically relevant insights can be attained from FE analysis of atrioventricular valves without precise knowledge of tissue properties. As such we investigated 1) the influence of tissue extensibility and 2) the effects of constitutive model parameters and leaflet thickness on simulated valve function and mechanics. We compared metrics of valve function (e.g., leaflet coaptation and regurgitant orifice area) and mechanics (e.g., stress and strain) across one normal and three regurgitant mitral valve (MV) models with common mechanisms of regurgitation (annular dilation, leaflet prolapse, leaflet tethering) of both moderate and severe degree. We developed a novel fully-automated approach to accurately quantify regurgitant orifice areas of complex valve geometries. We found that the relative ordering of the mechanical and functional metrics was maintained across a group of valves using material properties up to 15% softer than the representative adult mitral constitutive model. Our findings suggest that FE simulations can be used to qualitatively compare how differences and alterations in valve structure affect relative atrioventricular valve function even in populations where material properties are not precisely known.

15.
J Mech Behav Biomed Mater ; 142: 105858, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37099920

RESUMO

Advances in three-dimensional imaging provide the ability to construct and analyze finite element (FE) models to evaluate the biomechanical behavior and function of atrioventricular valves. However, while obtaining patient-specific valve geometry is now possible, non-invasive measurement of patient-specific leaflet material properties remains nearly impossible. Both valve geometry and tissue properties play a significant role in governing valve dynamics, leading to the central question of whether clinically relevant insights can be attained from FE analysis of atrioventricular valves without precise knowledge of tissue properties. As such we investigated (1) the influence of tissue extensibility and (2) the effects of constitutive model parameters and leaflet thickness on simulated valve function and mechanics. We compared metrics of valve function (e.g., leaflet coaptation and regurgitant orifice area) and mechanics (e.g., stress and strain) across one normal and three regurgitant mitral valve (MV) models with common mechanisms of regurgitation (annular dilation, leaflet prolapse, leaflet tethering) of both moderate and severe degree. We developed a novel fully-automated approach to accurately quantify regurgitant orifice areas of complex valve geometries. We found that the relative ordering of the mechanical and functional metrics was maintained across a group of valves using material properties up to 15% softer than the representative adult mitral constitutive model. Our findings suggest that FE simulations can be used to qualitatively compare how differences and alterations in valve structure affect relative atrioventricular valve function even in populations where material properties are not precisely known.


Assuntos
Insuficiência da Valva Mitral , Valva Mitral , Adulto , Humanos
16.
Eur J Cardiothorac Surg ; 63(6)2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-36857588

RESUMO

OBJECTIVES: This study aimed to determine the longitudinal change of systemic ventricular function and atrioventricular valve (AVV) regurgitation after total cavopulmonary connection (TCPC). METHODS: In 620 patients who underwent TCPC between 1994 and 2021, 4219 longitudinal echocardiographic examinations of systemic ventricular function and AVV regurgitation were evaluated retrospectively. RESULTS: The most frequent primary diagnosis was hypoplastic left heart syndrome in 172, followed by single ventricle in 131, tricuspid atresia in 95 and double inlet left ventricle (LV) in 91 patients. Dominant right ventricle (RV) was observed in 329 (53%) and dominant LV in 291 (47%). The median age at TCPC was 2.3 (1.8-3.4) years. Transplant-free survival at 5, 10 and 15 years after TCPC was 96.3%, 94.7% and 93.6%, respectively, in patients with dominant RV and 97.3%, 94.6% and 94.6%, respectively, in those with dominant LV (P = 0.987). Longitudinal analysis of systemic ventricular function was similar in both groups during the first 10 years postoperatively. Thereafter, systemic ventricular function worsened significantly in patients with dominant RV, compared with those with dominant LV (15 years: P = 0.007, 20 years: P = 0.03). AVV regurgitation was more frequent after TCPC in patients with dominant RV compared with those with dominant LV (P < 0.001 at 3 months, 3 years, 5 years, 10 years and 15 years, P = 0.023 at 20 years). There was a significant correlation between postoperative systemic ventricular dysfunction and AVV regurgitation (P < 0.001). CONCLUSIONS: There were no transplant-free survival difference and no difference in ventricular function between dominant RV and dominant LV for the first 10 years after TCPC. Thereafter, ventricular function in dominant RV was inferior to that in dominant LV. The degree of AVV regurgitation was significantly higher in dominant RV, compared with dominant LV, and it was positively associated with ventricular dysfunction, especially in dominant RV.


Assuntos
Técnica de Fontan , Disfunção Ventricular , Humanos , Pré-Escolar , Técnica de Fontan/métodos , Resultado do Tratamento , Estudos Retrospectivos , Função Ventricular , Ventrículos do Coração
17.
Front Cardiovasc Med ; 9: 888258, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35911536

RESUMO

Objective: To evaluate the efficacy and safety of different surgical strategies to preserve pulmonary valve function. Surgical procedures evaluated include intraoperative balloon pulmonary valvuloplasty (IBPV), pulmonary valve reconstruction, and commissurotomy and pulmonary cusp augmentation (PCA) in patients who underwent a radical operation for Tetralogy of Fallot (ToF). Materials and Methods: The five databases searched in the current study included the Cochrane Library, PubMed, China National Knowledge Infrastructure, VIP, and WanFang data. A systematic search for control trials was performed in each database from the start date of each database until December 2021. The Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of included studies. Results: A total of 15 retrospective studies with a total number of 1,396 participants were included in this study. In subgroup 1 (IBPV vs. TAP), patients undergoing IBPV had a less degree of regurgitation at 1-2 years after the surgery. The reintervention rate increased in the IBPV group at 5 years. In subgroup 2 (pulmonary valve reconstruction vs. TAP), the degree of regurgitation decreased in the pulmonary valve reconstruction group at 1 month after the surgery. In subgroup 3 (valve-sparing operation vs. TAP), the comparison demonstrated decreased rates for surgical mortality and reintervention at 5-10 years after the surgery. Conclusion: We proposed that pulmonary valve function in a radical operation for ToF was preserved. IBPV, pulmonary valve reconstruction, and commissurotomy and PCA can be performed during the surgical procedure based on the developmental status and anatomical characteristics of the right ventricular outflow tract (RVOT), pulmonary valve, and pulmonary artery. Systematic Review Registration: [https://www.crd.york.ac.uk/prospero/], identifier [CRD42022300987].

18.
J Clin Med ; 11(1)2021 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-35011829

RESUMO

BACKGROUND: Lead-related tricuspid valve dysfunction (LDTVD) has not been studied in a large population and its management remains controversial. METHODS: An analysis of the clinical data of 2678 patients undergoing transvenous lead extraction (TLE) in years 2008-2021 was conducted, with a separate group of 119 patients with LDTVD. Potential risk factors for LDTVD, improvement in valve function, and long-term prognosis after TLE were assessed. RESULTS: LDTVD was diagnosed in 4.44% of patients referred for lead extraction due to different reasons. The most common mechanism of LDTVD was propping upward or clamping down the leaflet by the lead (85.71%). The probability of LDTVD was higher in female sex, patients with valvular heart disease, atrial fibrillation, heart failure, large right ventricle and high pulmonary artery systolic pressure, the presence of only pacing lead, and in case of collision of the lead with tricuspid valve and adhesion of the lead to the heart structures. The prognosis of patients with LDTVD was worse, however, patients with improved valve function after TLE showed a significantly better long-term survival. CONCLUSIONS: Lead dependent tricuspid valve dysfunction is a potentially serious condition that requires thorough diagnostics and thoughtful management. The risk factors for LDTVD are primarily related to the course of the lead and its adhesion to the heart structures. Improvement of tricuspid valve function after TLE is observed in 35.29% of patients Patients with LDTVD have a worse long-term survival, but the improvement in valve function following TLE contributes to a significant reduction in mortality.

19.
Front Cardiovasc Med ; 7: 603323, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33505993

RESUMO

Background: Using echocardiographic surveillance, many patients are diagnosed with bicuspid aortic valve (BAV) without significant valve dysfunction. Limited data are available regarding the progression and outcomes of non-dysfunctional BAV. Methods and Results: We investigated 1,307 BAV patients (984 male, mean age 56 years) diagnosed from Jan 2003 through Dec 2018 in a single tertiary center. Seven hundred sixty-one patients underwent follow-up echocardiography at ≥1 year post-diagnosis. Non-dysfunctional BAV was defined as BAV without moderate aortic stenosis (AS) or aortic regurgitation (AR). The presence of aortopathy was defined as an ascending aorta diameter >37mm. Progression to significant BAV dysfunction, progression to severe aortopathy (ascending aorta diameter ≥45mm), and incidence of valve or aorta operation were analyzed. One hundred eighty-seven (25%) patients showed non-dysfunctional BAV. Among them, 104 (56%) had mild AS or AR, and 81 (43%) had aortopathy at indexed echocardiography. At 6.0 ± 3.8 years post-diagnosis, 56 (29%) progressed to dysfunctional BAV, 28 (15%) progressed to severe aortopathy, 22 (12%) underwent valve operation, and 19 (10%) experienced aorta operation. Eighty-nine percent of patients with normal BAV function and 61% of patients with mild AS or AR maintained non-dysfunctional BAV. More patients with aortopathy progressed to severe aortopathy (35 vs. 0% without aortopathy, p < 0.001), with a higher incidence of aorta operation (21 vs. 2%, p < 0.001). Conclusions: In patients with non-dysfunctional BAV, initial BAV function and degree of aorta dilatation might be important for progression and outcomes. Patients without any dysfunction or aortopathy tend to maintain good structure and function for 6 years.

20.
Exp Gerontol ; 140: 111075, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-32861845

RESUMO

BACKGROUND: LDLr-/-/ApoB100/100/IGF-II+/- mice are used as a calcific aortic valve disease (CAVD) model. However, normal aortic valve hemodynamics i.e. remotely from CAVD onset and the sex-related differences are poorly known. METHODS AND RESULTS: Four groups of mice, intact males (IM, n = 49) and females (IF, n = 50), castrated males (CxM, n = 79) and ovariectomized females (OxF: 73), underwent a Doppler-echocardiography at 12 weeks of age. Gonadectomy was performed at 8 weeks. Aortic valve assessment using effective orifice area (EOA, using the continuity equation) and peak aortic transvalvular velocity (VPeak) was feasible in 89% of the mice with good to excellent reliability (intraclass correlation coefficients ranging from 0.90 to 0.98, p < 0.001). Mean VPeak was 104 ± 17 cm/s and mean EOA was 1.18*10-2 ± 0.22*10-2 cm2. EOA indexed to body surface area was 1.5 ± 0.3 cm2/m2. The 95th percentile of Vpeak was 132 cm/s and the 5th percentile of indexed EOA was 1.0 cm2/m2. Interestingly, IM had the highest VPeak (114 ± 14 cm/s) vs each of the other groups (CxM: 106 ± 19 cm/s, OxF: 97 ± 13 cm/s and IF: 96 ± 12 cm/s, ANOVA and corrected p < 0.001). This was mostly explained by a higher stroke volume (ANOVA and corrected p < 0.001) in IM compared to other groups. There were no major sex-differences in ventricular systolic function parameters. CONCLUSION: In LDLr-/-/ApoB100/100/IGF-II CAVD mice model, an aortic EOA <0.8*10-2 cm2 (or indexed EOA <1.0cm2/m2), and a peak aortic valve velocity > 132 cm/s may be proposed as thresholds to define CAVD. Intact male mice appear to have higher velocities.


Assuntos
Estenose da Valva Aórtica , Valva Aórtica , Animais , Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/diagnóstico por imagem , Apolipoproteína B-100/genética , Feminino , Fator de Crescimento Insulin-Like II , Masculino , Camundongos , Reprodutibilidade dos Testes
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