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Mitral Annular Disjunction
Mitral annular disjunction (MAD) is a structural abnormality of the heart in the mitral annulus ring. It is generally defined as an abnormal displacement of the location of where the posterior mitral valve leaflet inserts onto the left atrial wall and the left ventricular wall. This abnormal attachment allows for the mitral valve to become hypermobile and can result in ventricular arrhythmias. History MAD was first described in 1986 through autopsy analysis of hearts while investigating the incidence of mitral valve prolapse. Pathophysiology The cause of MAD is not well understood. Hypotheses of congenital, degenerative, and acquired structural abnormalities exist. However, the physical characteristics of MAD are able to be observed through a variety of cardiac imaging techniques. Normally the posterior aspect of the mitral annulus is attached to the posterior aspect of the left ventricular wall. In MAD, there is a distinct separation between the mitral annular ring and left ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitral Valve * Válvula Bicúspide
The mitral valve (), also known as the bicuspid valve or left atrioventricular valve, is one of the four heart valves. It has two cusps or flaps and lies between the left atrium and the left ventricle of the heart. The heart valves are all one-way valves allowing blood flow in just one direction. The mitral valve and the tricuspid valve are known as the atrioventricular valves because they lie between the atria and the ventricles. In normal conditions, blood flows through an open mitral valve during diastole with contraction of the left atrium, and the mitral valve closes during systole with contraction of the left ventricle. The valve opens and closes because of pressure differences, opening when there is greater pressure in the left atrium than ventricle and closing when there is greater pressure in the left ventricle than atrium. In abnormal conditions, blood may flow backward through the valve (mitral regurgitation) or the mitral valve may be narrowed (mitral stenosis). Rheu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heart
The heart is a muscular organ found in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide to the lungs. In humans, the heart is approximately the size of a closed fist and is located between the lungs, in the middle compartment of the chest, called the mediastinum. In humans, other mammals, and birds, the heart is divided into four chambers: upper left and right atria and lower left and right ventricles. Commonly, the right atrium and ventricle are referred together as the right heart and their left counterparts as the left heart. Fish, in contrast, have two chambers, an atrium and a ventricle, while most reptiles have three chambers. In a healthy heart, blood flows one way through the heart due to heart valves, which prevent backflow. The heart is enclosed in a protective sac, the pericardium, which also contains ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitral Valve
The mitral valve (), also known as the bicuspid valve or left atrioventricular valve, is one of the four heart valves. It has two cusps or flaps and lies between the left atrium and the left ventricle of the heart. The heart valves are all one-way valves allowing blood flow in just one direction. The mitral valve and the tricuspid valve are known as the atrioventricular valves because they lie between the atria and the ventricles. In normal conditions, blood flows through an open mitral valve during diastole with contraction of the left atrium, and the mitral valve closes during systole with contraction of the left ventricle. The valve opens and closes because of pressure differences, opening when there is greater pressure in the left atrium than ventricle and closing when there is greater pressure in the left ventricle than atrium. In abnormal conditions, blood may flow backward through the valve ( mitral regurgitation) or the mitral valve may be narrowed ( mitral stenosis). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atrium (heart)
The atrium ( la, ātrium, , entry hall) is one of two upper chambers in the heart that receives blood from the circulatory system. The blood in the atria is pumped into the heart ventricles through the atrioventricular valves. There are two atria in the human heart – the left atrium receives blood from the pulmonary circulation, and the right atrium receives blood from the venae cavae of the systemic circulation. During the cardiac cycle the atria receive blood while relaxed in diastole, then contract in systole to move blood to the ventricles. Each atrium is roughly cube-shaped except for an ear-shaped projection called an atrial appendage, sometimes known as an auricle. All animals with a closed circulatory system have at least one atrium. The atrium was formerly called the 'auricle'. That term is still used to describe this chamber in some other animals, such as the ''Mollusca''. They have thicker muscular walls than the atria do. Structure Humans have a four-c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ventricle (heart)
A ventricle is one of two large chambers toward the bottom of the heart that collect and expel blood towards the peripheral beds within the body and lungs. The blood pumped by a ventricle is supplied by an atrium (heart), atrium, an adjacent chamber in the upper heart that is smaller than a ventricle. Interventricular means between the ventricles (for example the interventricular septum), while intraventricular means within one ventricle (for example an intraventricular block). In a four-chambered heart, such as that in humans, there are two ventricles that operate in a double circulatory system: the right ventricle pumps blood into the pulmonary circulation to the lungs, and the left ventricle pumps blood into the systemic circulation through the aorta. Structure Ventricles have thicker walls than atria and generate higher blood pressures. The physiological load on the ventricles requiring pumping of blood throughout the body and lungs is much greater than the pressure generated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypermobility Spectrum Disorder
Hypermobility spectrum disorder (HSD), related to earlier diagnoses such as hypermobility syndrome (HMS), and joint hypermobility syndrome (JHS) is a heritable connective tissue disorder that affects joints and ligaments. Different forms and sub-types have been distinguished, but it does not include asymptomatic joint hypermobility, sometimes known as double-jointedness. Symptoms can include the inability to walk properly or for long distances, and pain in affected areas. Some people with HSD have hypersensitive nerves and a weaker immune system. It can also cause severe fatigue and some cases cause depressive episodes. It is somewhat similar to other genetic connective tissue disorders such as Ehlers–Danlos syndromes. There is a strong association between HSD and neurodevelopmental disorders such as ADHD ( Attention deficit hyperactivity disorder) and ASD ( autism spectrum disorder). Classification Hypermobility spectrum disorders are diagnosed when individuals have sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitral Valve RK
The mitral valve (), also known as the bicuspid valve or left atrioventricular valve, is one of the four heart valves. It has two cusps or flaps and lies between the left atrium and the left ventricle of the heart. The heart valves are all one-way valves allowing blood flow in just one direction. The mitral valve and the tricuspid valve are known as the atrioventricular valves because they lie between the atria and the ventricles. In normal conditions, blood flows through an open mitral valve during diastole with contraction of the left atrium, and the mitral valve closes during systole with contraction of the left ventricle. The valve opens and closes because of pressure differences, opening when there is greater pressure in the left atrium than ventricle and closing when there is greater pressure in the left ventricle than atrium. In abnormal conditions, blood may flow backward through the valve (mitral regurgitation) or the mitral valve may be narrowed (mitral stenosis). Rheu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Histopathology Of Mitral Valve With Myxomatous Degeneration
Histopathology (compound of three Greek words: ''histos'' "tissue", πάθος ''pathos'' "suffering", and -λογία ''-logia'' "study of") refers to the microscopic examination of tissue in order to study the manifestations of disease. Specifically, in clinical medicine, histopathology refers to the examination of a biopsy or surgical specimen by a pathologist, after the specimen has been processed and histological sections have been placed onto glass slides. In contrast, cytopathology examines free cells or tissue micro-fragments (as "cell blocks"). Collection of tissues Histopathological examination of tissues starts with surgery, biopsy, or autopsy. The tissue is removed from the body or plant, and then, often following expert dissection in the fresh state, placed in a fixative which stabilizes the tissues to prevent decay. The most common fixative is 10% neutral buffered formalin (corresponding to 3.7% w/v formaldehyde in neutral buffered water, such as phosphate buf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transthoracic Echocardiography
An echocardiography, echocardiogram, cardiac echo or simply an echo, is an ultrasound of the heart. It is a type of medical imaging of the heart, using standard ultrasound or Doppler ultrasound. Echocardiography has become routinely used in the diagnosis, management, and follow-up of patients with any suspected or known heart diseases. It is one of the most widely used diagnostic imaging modalities in cardiology. It can provide a wealth of helpful information, including the size and shape of the heart (internal chamber size quantification), pumping capacity, location and extent of any tissue damage, and assessment of valves. An echocardiogram can also give physicians other estimates of heart function, such as a calculation of the cardiac output, ejection fraction, and diastolic function (how well the heart relaxes). Echocardiography is an important tool in assessing wall motion abnormality in patients with suspected cardiac disease. It is a tool which helps in reaching an earl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CT Scan
A computed tomography scan (CT scan; formerly called computed axial tomography scan or CAT scan) is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or radiology technologists. CT scanners use a rotating X-ray tube and a row of detectors placed in a gantry to measure X-ray attenuations by different tissues inside the body. The multiple X-ray measurements taken from different angles are then processed on a computer using tomographic reconstruction algorithms to produce tomographic (cross-sectional) images (virtual "slices") of a body. CT scans can be used in patients with metallic implants or pacemakers, for whom magnetic resonance imaging (MRI) is contraindicated. Since its development in the 1970s, CT scanning has proven to be a versatile imaging technique. While CT is most prominently used in medical diagnosis, it can also be used to form images of non-living objects. The 1979 N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardiac Magnetic Resonance Imaging
Cardiac magnetic resonance imaging (cardiac MRI), also known as cardiovascular MRI, is a magnetic resonance imaging (MRI) technology used for non-invasive assessment of the function and structure of the cardiovascular system. Conditions in which it is performed include congenital heart disease, cardiomyopathies and valvular heart disease, diseases of the aorta such as dissection, aneurysm and coarctation, coronary heart disease and it can be used to look at pulmonary veins. It is contraindicated if there is a permanent pacemaker or defibrillator, intracerebral clips or claustrophobia. Conventional MRI sequences are adapted for cardiac imaging by using ECG gating and high temporal resolution protocols. The development of cardiac MRI is an active field of research and continues to see a rapid expansion of new and emerging techniques. Uses Cardiovascular MRI is complementary to other imaging techniques, such as echocardiography, cardiac CT, and nuclear medicine. The technique ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitral Valve Prolapse
Mitral valve prolapse (MVP) is a valvular heart disease characterized by the displacement of an abnormally thickened mitral valve leaflet into the left atrium during systole. It is the primary form of myxomatous degeneration of the valve. There are various types of MVP, broadly classified as classic and nonclassic. In severe cases of classic MVP, complications include mitral regurgitation, infective endocarditis, congestive heart failure, and, in rare circumstances, cardiac arrest. The diagnosis of MVP depends upon echocardiography, which uses ultrasound to visualize the mitral valve. MVP is the most common valvular abnormality and is estimated to affect 2–3% of the population and 1 in 40 people might have it. The condition was first described by John Brereton Barlow in 1966. It was subsequently termed ''mitral valve prolapse'' by J. Michael Criley. Although mid-systolic click (sound of prolapsing mitral leaflet) and systolic murmur have been noticed earlier with stethos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
