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Diastolic Dysfunction
Heart failure with preserved ejection fraction (HFpEF) is a form of heart failure in which the ejection fraction – the percentage of the volume of blood ejected from the left ventricle with each heartbeat divided by the volume of blood when the left ventricle is maximally filled – is normal, defined as greater than 50%; this may be measured by echocardiography or cardiac catheterization. Approximately half of people with heart failure have preserved ejection fraction, while the other half have a reduction in ejection fraction, called heart failure with reduced ejection fraction (HFrEF). Risk factors for HFpEF include hypertension, hyperlipidemia, diabetes, smoking, and obstructive sleep apnea. Those with HFpEF have a higher prevalence of obesity, type 2 diabetes, hypertension, atrial fibrillation and chronic kidney disease than those with heart failure with reduced ejection fraction. The prevalence of HFpEF is expected to increase as more people develop obesity and other medi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heart Failure
Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome caused by an impairment in the heart's ability to Cardiac cycle, fill with and pump blood. Although symptoms vary based on which side of the heart is affected, HF typically presents with shortness of breath, Fatigue (medical), excessive fatigue, and bilateral peripheral edema, leg swelling. The severity of the heart failure is mainly decided based on ejection fraction and also measured by the severity of symptoms. Other conditions that have symptoms similar to heart failure include obesity, kidney failure, liver disease, anemia, and thyroid disease. Common causes of heart failure include coronary artery disease, heart attack, hypertension, high blood pressure, atrial fibrillation, valvular heart disease, alcohol use disorder, excessive alcohol consumption, infection, and cardiomyopathy. These cause heart failure by altering the structure or the function of the heart or in some cases both. There are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthopnea
Orthopnea or orthopnoea is shortness of breath (dyspnea) that occurs when lying flat, causing the person to have to sleep propped up in bed or sitting in a chair. It is commonly seen as a late manifestation of heart failure, resulting from fluid redistribution into the central circulation, causing an increase in pulmonary capillary pressure and causing difficulty in breathing. It is also seen in cases of abdominal obesity or pulmonary disease. Orthopnea is the opposite of platypnea, shortness of breath that worsens when sitting or standing upright. Causes Orthopnea is often a symptom of left ventricular heart failure and/or cardiogenic pulmonary edema. It can also occur in those with asthma and chronic bronchitis, as well as those with sleep apnea or panic disorder. It is also as associated with polycystic liver disease. From a neuromuscular perspective, orthopnea is potentially a sign of severe diaphragmatic weakness. Under such circumstances, patients may describe shortness ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microvasculature
The microcirculation is the circulation of the blood in the smallest blood vessels, the microvessels of the microvasculature present within organ tissues. The microvessels include terminal arterioles, metarterioles, capillaries, and venules. Arterioles carry oxygenated blood to the capillaries, and blood flows out of the capillaries through venules into veins. In addition to these blood vessels, the microcirculation also includes lymphatic capillaries and collecting ducts. The main functions of the microcirculation are the delivery of oxygen and nutrients and the removal of carbon dioxide (CO2). It also serves to regulate blood flow and tissue perfusion, thereby affecting blood pressure and responses to inflammation which can include edema (swelling). Most vessels of the microcirculation are lined by flattened cells of the endothelium and many of them are surrounded by contractile cells called pericytes. The endothelium provides a smooth surface for the flow of blood and regu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronary Artery Disease
Coronary artery disease (CAD), also called coronary heart disease (CHD), or ischemic heart disease (IHD), is a type of cardiovascular disease, heart disease involving Ischemia, the reduction of blood flow to the cardiac muscle due to a build-up of atheromatous plaque in the Coronary arteries, arteries of the heart. It is the most common of the cardiovascular diseases. CAD can cause stable angina, unstable angina, myocardial ischemia, and myocardial infarction. A common symptom is angina, which is chest pain or discomfort that may travel into the shoulder, arm, back, neck, or jaw. Occasionally it may feel like heartburn. In stable angina, symptoms occur with exercise or emotional Psychological stress, stress, last less than a few minutes, and improve with rest. Shortness of breath may also occur and sometimes no symptoms are present. In many cases, the first sign is a Myocardial infarction, heart attack. Other complications include heart failure or an Heart arrhythmia, abnormal h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myocardium
Cardiac muscle (also called heart muscle or myocardium) is one of three types of vertebrate muscle tissues, the others being skeletal muscle and smooth muscle. It is an involuntary, striated muscle that constitutes the main tissue of the wall of the heart. The cardiac muscle (myocardium) forms a thick middle layer between the outer layer of the heart wall (the pericardium) and the inner layer (the endocardium), with blood supplied via the coronary circulation. It is composed of individual cardiac muscle cells joined by intercalated discs, and encased by collagen fibers and other substances that form the extracellular matrix. Cardiac muscle contracts in a similar manner to skeletal muscle, although with some important differences. Electrical stimulation in the form of a cardiac action potential triggers the release of calcium from the cell's internal calcium store, the sarcoplasmic reticulum. The rise in calcium causes the cell's myofilaments to slide past each other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ischemia
Ischemia or ischaemia is a restriction in blood supply to any tissue, muscle group, or organ of the body, causing a shortage of oxygen that is needed for cellular metabolism (to keep tissue alive). Ischemia is generally caused by problems with blood vessels, with resultant damage to or dysfunction of tissue, i.e., hypoxia and microvascular dysfunction. It also implies local hypoxia in a part of a body resulting from constriction (such as vasoconstriction, thrombosis, or embolism). Ischemia causes not only insufficiency of oxygen but also reduced availability of nutrients and inadequate removal of metabolic wastes. Ischemia can be partial (poor perfusion) or total blockage. The inadequate delivery of oxygenated blood to the organs must be resolved either by treating the cause of the inadequate delivery or reducing the oxygen demand of the system that needs it. For example, patients with myocardial ischemia have a decreased blood flow to the heart and are prescribe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypertrophy
Hypertrophy is the increase in the volume of an organ or tissue due to the enlargement of its component cells. It is distinguished from hyperplasia, in which the cells remain approximately the same size but increase in number. Although hypertrophy and hyperplasia are two distinct processes, they frequently occur together, such as in the case of the hormonally induced proliferation and enlargement of the cells of the uterus during pregnancy. Eccentric hypertrophy is a type of hypertrophy where the walls and chamber of a hollow organ undergo growth in which the overall size and volume are enlarged. It is applied especially to the left ventricle of heart. Sarcomeres are added in series, as for example in dilated cardiomyopathy (in contrast to hypertrophic cardiomyopathy, a type of concentric hypertrophy, where sarcomeres are added in parallel). Gallery Gould Pyle 234.jpg, Breasts Hypertrophied clitoris.jpg, Clitoris Head of a boy with hypertrophy of the ear Wellcome L0062496.j ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gross Anatomy
Gross anatomy is the study of anatomy at the visible or macroscopic level. The counterpart to gross anatomy is the field of histology, which studies microscopic anatomy. Gross anatomy of the human body or other animals seeks to understand the relationship between components of an organism in order to gain a greater appreciation of the roles of those components and their relationships in maintaining the functions of life. The study of gross anatomy can be performed on deceased organisms using dissection or on living organisms using medical imaging. Education in the gross anatomy of humans is included training for most health professionals. Techniques of study Gross anatomy is studied using both invasive and noninvasive methods with the goal of obtaining information about the macroscopic structure and organisation of organs and organ systems. Among the most common methods of study is dissection, in which the corpse of an animal or a human cadaver is surgically opened and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Afterload
Afterload is the pressure that the heart must work against to eject blood during systole (ventricular contraction). Afterload is proportional to the average arterial pressure. As aortic and pulmonary pressures increase, the afterload increases on the left and right ventricles respectively. Afterload changes to adapt to the continually changing demands on an animal's cardiovascular system. Afterload is proportional to mean systolic blood pressure and is measured in millimeters of mercury (mm Hg). Hemodynamics Afterload is a determinant of cardiac output. Cardiac output is the product of stroke volume and heart rate. Afterload is a determinant of stroke volume (in addition to preload, and strength of myocardial contraction). Following Laplace's law, the tension upon the muscle fibers in the heart wall is the pressure within the ventricle multiplied by the volume within the ventricle divided by the wall thickness (this ratio is the other factor in setting the afterload). The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aortic Stenosis
Aortic stenosis (AS or AoS) is the narrowing of the exit of the left ventricle of the heart (where the aorta begins), such that problems result. It may occur at the aortic valve as well as above and below this level. It typically gets worse over time. Symptoms often come on gradually with a decreased ability to exercise often occurring first. If heart failure, loss of consciousness, or heart related chest pain occur due to AS the outcomes are worse. Loss of consciousness typically occurs with standing or exercising. Signs of heart failure include shortness of breath especially when lying down, at night, or with exercise, and swelling of the legs. Thickening of the valve without causing obstruction is known as aortic sclerosis. Causes include being born with a bicuspid aortic valve, and rheumatic fever; a normal valve may also harden over the decades due to calcification. A bicuspid aortic valve affects about one to two percent of the population. As of 2014 rheumatic heart ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metabolic Syndrome
Metabolic syndrome is a clustering of at least three of the following five medical conditions: abdominal obesity, high blood pressure, high blood sugar, high serum triglycerides, and low serum high-density lipoprotein (HDL). Metabolic syndrome is associated with the risk of developing cardiovascular disease and type 2 diabetes. In the U.S., about 25% of the adult population has metabolic syndrome, a proportion increasing with age, particularly among racial and ethnic minorities. Insulin resistance, metabolic syndrome, and prediabetes are closely related to one another and have overlapping aspects. The syndrome is thought to be caused by an underlying disorder of energy utilization and storage, but the cause of the syndrome is an area of ongoing medical research. Researchers debate whether a diagnosis of metabolic syndrome implies differential treatment or increases risk of cardiovascular disease beyond what is suggested by the sum of its individual components. Signs and s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Obesity
Obesity is a medical condition, considered by multiple organizations to be a disease, in which excess Adipose tissue, body fat has accumulated to such an extent that it can potentially have negative effects on health. People are classified as obese when their body mass index (BMI)—a person's weight divided by the square of the person's height—is over ; the range is defined as overweight. Some East Asian countries use lower values to calculate obesity. Obesity is a major cause of disability and is Obesity-associated morbidity, correlated with various diseases and conditions, particularly cardiovascular diseases, type 2 diabetes, obstructive sleep apnea, certain types of cancer, and osteoarthritis. Obesity has individual, socioeconomic, and environmental causes. Some known causes are Western pattern diet, diet, low physical activity, automation, urbanization, quantitative trait locus, genetic susceptibility, medications, mental disorders, Economic policy, economic pol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
