Mechanical Valve

Background: There is emerging but conflicting evidence regarding the association between calcium biomarkers, more specifically ionized calcium and the prognosis of intensive care unit (ICU) postoperative cardiac patients. Methods : Our study investigated the relationship between ionized calcium, vitamin D, and periprocedural clinical events such as cardiac, neurologic and renal complications, major bleeding, vasoactive-inotropic score (VIS), and length of ICU and hospitalization. Results : Our study included 83 consecutive subjects undergoing elective major cardiac surgery requiring cardiopulmonary bypass...

Transcatheter aortic valve replacement (TAVR) has become an established alternative to surgical aortic valve replacement (AVR) for patients with moderate-to-high perioperative risk. Periprocedural TAVR complications decrease with growing expertise of implanters. Nevertheless, TAVR can still be accompanied by life-threatening adverse events such as intraprocedural cardiopulmonary resuscitation (CPR). This study analyzed the role of a reduced left-ventricular ejection fraction (LVEF) in intraprocedural complications during TAVR...

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There is increasing evidence that some adult mitral valve pathologies may have developmental origins involving errors in cell signaling and protein deposition during valvulogenesis. While early and late gestational stages are well-documented in zebrafish, chicks, and small mammalian models, longitudinal studies in large mammals with a similar gestational period to humans are lacking. Further, the mechanism of chordae tendineae formation and multiplication remains unclear. The current study presents a comprehensive examination of mitral anterior leaflet and chordae tendineae development in a bovine model (a large mammal with the same gestational period as humans)...

Aspirin has been known for a long time and currently stays as a cornerstone of antithrombotic therapy in cardiovascular disease. In patients with either acute or chronic coronary syndromes undergoing percutaneous coronary intervention aspirin is mandatory in a dual antiplatelet therapy regimen for prevention of stent thrombosis and/or new ischaemic events. Aspirin is also currently a first-option antithrombotic therapy after an aortic prosthetic valve replacement and is occasionally required in addition to oral anticoagulants after implantation of a mechanical valve...

Aortic insufficiency (AI) is a valvular disease with increasing prevalence in older patients. The modern era provides numerous options for the management of AI which is explored here. Traditional interventions included aortic valve replacement with either mechanical or bioprosthetic aortic valves. While the former is known for its durability, it has grown out of favor due to the potential complications of anticoagulation. The preference for bioprosthetic valves is thus on the rise, especially with the advancements of transcatheter technology and the use of valve-in-valve therapy...

BACKGROUND: Myxomatous valve disease (MVD) is the most common cause of mitral regurgitation, leading to impaired cardiac function and heart failure. MVD in a mouse model of Marfan syndrome includes valve leaflet thickening and progressive valve degeneration. However, the underlying mechanisms by which the disease progresses remain undefined. METHODS: Mice with Fibrillin 1 gene variant Fbn1 C1039G/+ recapitulate histopathologic features of Marfan syndrome, and Wnt signaling activity was detected in TCF/Lef-lacZ reporter mice...

Tricuspid valve disease is an often underrecognized clinical problem that is associated with significant morbidity and mortality. Unfortunately, patients will often present late in their disease course with severe right-sided heart failure, pulmonary hypertension, and life-limiting symptoms that have few durable treatment options. Traditionally, the only treatment for tricuspid valve disease has been medical therapy or surgery; however, there have been increasing interest and success with the use of transcatheter tricuspid valve therapies over the past several years to treat patients with previously limited therapeutic options...

INTRODUCTION: Neural crest cells (NCCs) are multipotent and are attributed to the combination of complex multimodal gene regulatory mechanisms. Cardiac neural crest (CNC) cells, originating from the dorsal neural tube, are pivotal architects of the cardio-neuro-vascular domain, which orchestrates the embryogenesis of critical cardiac and vascular structures. Remarkably, while the scientific community compiled a comprehensive inventory of neural crest derivatives by the early 1980s, our understanding of the CNC's role in various cardiovascular disease processes still needs to be explored...

Microvalves play a crucial role in manipulating fluid states within a microfluidic system and are finding widespread applications in fields such as biology, medicine, and environmental preservation. Leveraging the characteristics and features of microvalves enables the realization of various complicated microfluidic functions. Continuous advancement in the manufacturing process contributes to more flexible control modes for passive microvalves. As a consequence, these valves are progressively shrinking in size while simultaneously improving in precision and stability...

OBJECTIVE: To illustrate the clinical features and management of pneumatocoele presenting with a trap-valve mechanism after cochlear implantation with lateral petrosectomy (LP) in comparison with literature. INTRODUCTION: Pneumatocoele is a rare complication of cochlear implant (CI) surgery, generally managed with conservative treatments. METHODS: We describe a progressively increasing pneumatocoele with a trap-valve mechanism occurring one year after CI with LP, successfully managed with revision surgery...

To enhance the vibration system characteristic distortion and pressure loss, we propose a novel rotary valve control vibration system. The paper presents the designed structural composition and generation mechanism of the rotary valve control vibration system. It also derives the mathematical model for the rotary valve distribution process and the overall system. The flow field inside the rotary valve is dynamically simulated using the multiple reference frame model, allowing for the determination of the change rule of the rotary valve's output characteristics...

BACKGROUND: Extravalvular cardiac damage caused by aortic stenosis affects prognosis after transcatheter aortic valve replacement (TAVR). The long-term impact of changes in cardiac damage in response to relief from mechanical obstruction has not been fully investigated. OBJECTIVES: The authors aimed to investigate changes in cardiac damage early after TAVR and the prognostic impact of the cardiac damage classification after TAVR. METHODS: In this single-center observational study, patients undergoing transfemoral TAVR were retrospectively evaluated for cardiac damage before and after TAVR and classified into 5 stages of cardiac damage (0-4)...

BACKGROUND: Symptomatic patients with severe aortic stenosis (AS) at high risk for surgical aortic valve replacement (SAVR) sustain comparable improvements in health status over 5 years after transcatheter aortic valve replacement (TAVR) or SAVR. Whether a similar long-term benefit is observed among intermediate-risk AS patients is unknown. OBJECTIVES: The purpose of this study was to assess health status outcomes through 5 years in intermediate risk patients treated with a self-expanding TAVR prosthesis or SAVR using data from the SURTAVI (Surgical Replacement and Transcatheter Aortic Valve Implantation) trial...

A microfluidic pump is presented that generates its pumping action via the EWOD (electrowetting-on-dielectric) effect. The flow is generated by the periodic movement of liquid-vapor interfaces in a large number (≈106 ) of microcavities resulting in a volume change of approx. 0.5 pl per cavity per pump stroke. The total flow resulting from all microcavities adds up to a few hundred nanolitres per cycle. Passive, topologically optimized, non-mechanical Tesla valves are used to rectify the flow. As a result, the micropump operates without any moving components...

The intra-aortic balloon pump (IABP) is a mechanical device that increases myocardial oxygen perfusion and indirectly increases cardiac output through afterload reduction. Since its inception, the IABP has been a mainstay of cardiac support devices, utilized as a temporizing measure in patients with or prone to developing cardiogenic shock that are awaiting definitive treatment. Systolic anterior motion (SAM) of the mitral valve is a well-described phenomenon that can precipitate hemodynamic collapse by obstructing the left ventricular outflow tract in a subset of patients with cardiac pathology, most notably hypertrophic obstructive cardiomyopathy (HOCM)...

BACKGROUND: Transcatheter aortic valve replacement (TAVR) has revolutionized the treatment of aortic stenosis. However, conduction disturbances leading to pacemaker implantation remain a common complication, increasing morbidity and mortality in these patients. Hence, measures to lower its incidence should be taken, and corticosteroid therapy could be effective by reducing inflammation caused by direct mechanical trauma to the conduction system. METHODS: A retrospective cohort study was conducted at the Centro Hospitalar de Vila Nova de Gaia/Espinho, analyzing the medical records of patients with native severe aortic stenosis who underwent transfemoral TAVR in 2022...

Penn State University is developing a pediatric total artificial heart (pTAH) as a bridge-to-transplant device that supports infants and small children with single ventricle anomalies or biventricular heart failure to address high waitlist mortality rates for patients with severe congenital heart disease. Two issues with mechanical circulatory support devices are thrombus formation and thromboembolic events. This in vitro study characterizes flow within Penn State's pTAH under physiological operating conditions...

BACKGROUND: The impact of mechanical ventilation on the survival of patients supported with veno-venous extracorporeal membrane oxygenation (V-V ECMO) due to severe acute respiratory distress syndrome (ARDS) remains still a focus of research. METHODS: Recent guidelines, randomized trials, and registry data underscore the importance of lung-protective ventilation during respiratory and cardiac support on ECMO. RESULTS: This approach includes decreasing mechanical power delivery by reducing tidal volume and driving pressure as much as possible, using low or very low respiratory rate, and a personalized approach to positive-end expiratory pressure (PEEP) setting...

BACKGROUND: In vitro assessment is mandatory for artificial heart valve development. This study aims to investigate the effects of pulse duplicator features on valve responsiveness, conduct a sensitivity analysis across valve prosthesis types, and contribute on the development of versatile pulse duplicator systems able to perform reliable prosthetic aortic valve assessment under physiologic hemodynamic conditions. METHODS: A reference pulse duplicator was established based on literature...