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The Role of Flaxseed Micronutrients and Nitric Oxide (NO) in Blood Vessel and Heart Function
Published in Robert Fried, Richard M. Carlton, Flaxseed, 2023
Robert Fried, Richard M. Carlton
The lower chambers, the more muscular right and left ventricles, pump blood out of the heart. The heart valves, which keep blood flowing in the right direction, are gates at the entrance to the chambers, preventing blood from flowing back when the ventricle chambers contract.
Cardiovascular Disease
Published in John S. Axford, Chris A. O'Callaghan, Medicine for Finals and Beyond, 2023
Cardiac surgery is an effective treatment for ischaemic heart disease and valve disease, relieving symptomatic angina and prolonging survival in selected patient groups. Standard indications for coronary artery bypass surgery include left main stem or triple vessel coronary artery disease, particularly in patients with diabetes and/or LV dysfunction where there is prognostic benefit. Surgery is offered for severe heart valve disease providing specific criteria are met, with either repair or replacement with bioprosthetic or mechanical valves. Surgical treatments for severe HF include cardiac transplantation or LV assist device implantation for eligible patients. Patients with complex congenital heart disease frequently require surgical correction.
Ethics of Product Failure and the Courts
Published in Howard Winet, Ethics for Bioengineering Scientists, 2021
Unlike IUDs heart valves are life-saving devices. Their failure is almost always fatal unless the patient is near a cardiac surgery facility. Of the four heart valves, the aortic needs replacement most often, followed by the mitral valve at the entrance of the left ventricle. High ejection pressures generated by left ventricle systole contribute to turbulence at the aortic valve. The resulting shear and cavitation probably contribute to its failure with age. Such failure is often the result of calcification at the base of the valve leaves. Most replacements are glutaraldehyde pretreated porcine or bovine heart valves that are providing a highly cross-linked collagen matrix. Polymeric replacements, sometimes with metal components, have been tried. If the implant lasts long enough it will also fail due to calcification-induced stiffening of the valve leaflets. In the 1970s and 1980s a series of synthetic heart valves came on the market and failed; not because of calcification but due to poor manufacturing practices that helped convince the FDA to develop a GMP protocol.
Galectin-3 reflects the echocardiographic quantification of right ventricular failure
Published in Scandinavian Cardiovascular Journal, 2021
Uzair Ansari, Michael Behnes, Julia Hoffmann, Kathrin Weidner, Philip Kuche, Jonas Rusnak, Seung-Hyun Kim, Michele Natale, Nadine Reckord, Siegfried Lang, Ursula Hoffmann, Thomas Bertsch, Marc Fatar, Martin Borggrefe, Ibrahim Akin
Our present study incorporated a population subset of 91 patients derived from a collective who underwent routine echocardiography at between 2014 and 2016. This was determined after ascertaining the inclusion and exclusion criteria for this analysis. The inclusion criteria included all patients at risk of developing cardiovascular disease or already diagnosed with cardiovascular disease. The exclusion criteria encompassed all patients under 18 years of age and/or pregnant; those with mechanical heart valves; those having suffered from a myocardial infarction within the last 3 months and those patients who received an electrical cardioversion within the last 30 days. Patients with heart transplants, acute pulmonary embolism, transient ischemic attacks in the last 30 days, those with acute infections, and/or chronic kidney disease with an eGFR <40 mL/min were also excluded from the study. For this particular sub-study focusing on RVF, only patients with normal left ventricular ejection fraction (LVEF) were included in the study population. Moreover, patients with moderate and severe heart valve disorders, classified as either stenosis or regurgitation were also excluded. Due to difficulties pertaining to accurate diagnosis, patients with varying degrees of diastolic dysfunction could have been included in this study. However, the number of patients with severe degree of diastolic dysfunction is limited.
Increased utilization of bioprosthetic aortic valve technology:Trends, drivers, controversies and future directions
Published in Expert Review of Cardiovascular Therapy, 2021
Steven S. Qi, Rosemary F. Kelly, Richard Bianco, Frederick J. Schoen
Aortic stenosis (AS) is the most common and deleterious functional abnormality of the heart valves, and the most serious manifestation of the more general process of calcific aortic valve disease. Aortic valve replacement (AVR), using open surgical implantation (SAVR) of either mechanical valve (MV) or tissue valve substitutes, has been the standard of care for severe symptomatic aortic stenosis for approximately 6 decades. In recent years, transcatheter aortic valve implantation (TAVI) has become widely used, with considerable success. AVR markedly improves symptoms and quality of life and prolongs survival in patients with AS. Although the overall rates of valve-related complications are similar for MVs and tissue valves, the frequency of specific valve-related complications is markedly dependent on the prosthesis type, model, size, site of implantation and patient characteristics and comorbidities. [1–4] Some prosthesis-associated complications have been obviated or mitigated by progressive evolution in design, biomaterials and implantation techniques.
Mathematical modeling of the Fontan blood circulation supported with pediatric ventricular assist device
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2021
Ekaterina Rubtsova, Aleksandr Markov, Sergey Selishchev, Jamshid H. Karimov, Dmitry Telyshev
Comparison of Fontan circulation and normal circulation shows that vena cava pressure in Fontan circulation is significantly higher than the normal pressure, which entails systemic veins stretching. Moreover, due to absence of the pulmonary ventricle, venous return decreases which, according to the Frank-Starling mechanism, leads to a decrease in the cardiac output and eventually to circulatory failure (Table 2). The model of single-ventricular circulation consists of the ventricle, systemic and pulmonary vessels, and also includes two heart valves. The model is based on a biventricular circulation model of a pediatric patient. This means that all changes made to the model correspond to the Fontan procedure, and parameters that are not related to the pulmonary ventricle remain unchanged.