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Angina
Angina, also known as angina pectoris, is chest pain or pressure, usually caused by insufficient blood flow to the heart muscle (myocardium). It is most commonly a symptom of coronary artery disease. Angina is typically the result of partial obstruction or spasm of the arteries that supply blood to the heart muscle. The main mechanism of coronary artery obstruction is atherosclerosis as part of coronary artery disease. Other causes of angina include abnormal heart rhythms, heart failure and, less commonly, anemia. The term derives from the Latin ''angere'' ("to strangle") and ''pectus'' ("chest"), and can therefore be translated as "a strangling feeling in the chest". There is a relationship between severity of angina and degree of oxygen deprivation in the heart muscle. However, the severity of angina does not always match the degree of oxygen deprivation to the heart or the risk of a heart attack (myocardial infarction). Some people may experience severe pain even though t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardiology
Cardiology () is a branch of medicine that deals with disorders of the heart and the cardiovascular system. The field includes medical diagnosis and treatment of congenital heart defects, coronary artery disease, heart failure, valvular heart disease and electrophysiology. Physicians who specialize in this field of medicine are called cardiologists, a specialty of internal medicine. Pediatric cardiologists are pediatricians who specialize in cardiology. Physicians who specialize in cardiac surgery are called cardiothoracic surgeons or cardiac surgeons, a specialty of general surgery. Specializations All cardiologists study the disorders of the heart, but the study of adult and child heart disorders each require different training pathways. Therefore, an adult cardiologist (often simply called "cardiologist") is inadequately trained to take care of children, and pediatric cardiologists are not trained to treat adult heart disease. Surgical aspects are not included in cardiology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heart Attack
A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops to the coronary artery of the heart, causing damage to the heart muscle. The most common symptom is chest pain or discomfort which may travel into the shoulder, arm, back, neck or jaw. Often it occurs in the center or left side of the chest and lasts for more than a few minutes. The discomfort may occasionally feel like heartburn. Other symptoms may include shortness of breath, nausea, feeling faint, a cold sweat or feeling tired. About 30% of people have atypical symptoms. Women more often present without chest pain and instead have neck pain, arm pain or feel tired. Among those over 75 years old, about 5% have had an MI with little or no history of symptoms. An MI may cause heart failure, an irregular heartbeat, cardiogenic shock or cardiac arrest. Most MIs occur due to coronary artery disease. Risk factors include high blood pressure, smoking, diabetes, lack of e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endothelium
The endothelium is a single layer of squamous endothelial cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the rest of the vessel wall. Endothelial cells form the barrier between vessels and tissue and control the flow of substances and fluid into and out of a tissue. Endothelial cells in direct contact with blood are called vascular endothelial cells whereas those in direct contact with lymph are known as lymphatic endothelial cells. Vascular endothelial cells line the entire circulatory system, from the heart to the smallest capillaries. These cells have unique functions that include fluid filtration, such as in the glomerulus of the kidney, blood vessel tone, hemostasis, neutrophil recruitment, and hormone trafficking. Endothelium of the interior surfaces of the heart chambers is called endocardium. An impaired function can lead to serious health issues throug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platelet Aggregation
Platelets, also called thrombocytes (from Greek θρόμβος, "clot" and κύτος, "cell"), are a component of blood whose function (along with the coagulation factors) is to react to bleeding from blood vessel injury by clumping, thereby initiating a blood clot. Platelets have no cell nucleus; they are fragments of cytoplasm that are derived from the megakaryocytes of the bone marrow or lung, which then enter the circulation. Platelets are found only in mammals, whereas in other vertebrates (e.g. birds, amphibians), thrombocytes circulate as intact mononuclear cells. One major function of platelets is to contribute to hemostasis: the process of stopping bleeding at the site of interrupted endothelium. They gather at the site and, unless the interruption is physically too large, they plug the hole. First, platelets attach to substances outside the interrupted endothelium: ''adhesion''. Second, they change shape, turn on receptors and secrete chemical messengers: ''activation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pathophysiology
Pathophysiology ( physiopathology) – a convergence of pathology with physiology – is the study of the disordered physiological processes that cause, result from, or are otherwise associated with a disease or injury. Pathology is the medical discipline that describes conditions typically ''observed'' during a disease state, whereas physiology is the biological discipline that describes processes or mechanisms ''operating'' within an organism. Pathology describes the abnormal or undesired condition, whereas pathophysiology seeks to explain the functional changes that are occurring within an individual due to a disease or pathologic state. History Etymology The term ''pathophysiology'' comes from the Ancient Greek πάθος (''pathos'') and φυσιολογία (''phusiologia''). Nineteenth century Reductionism In Germany in the 1830s, Johannes Müller led the establishment of physiology research autonomous from medical research. In 1843, the Berlin Physical Socie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crescendo
In music, the dynamics of a piece is the variation in loudness between notes or phrases. Dynamics are indicated by specific musical notation, often in some detail. However, dynamics markings still require interpretation by the performer depending on the musical context: for instance, the ''forte'' marking (meaning loud) in one part of a piece might have quite different objective loudness in another piece or even a different section of the same piece. The execution of dynamics also extends beyond loudness to include changes in timbre and sometimes tempo rubato. Purpose and interpretation Dynamics are one of the expressive elements of music. Used effectively, dynamics help musicians sustain variety and interest in a musical performance, and communicate a particular emotional state or feeling. Dynamic markings are always relative. never indicates a precise level of loudness; it merely indicates that music in a passage so marked should be considerably quieter than . There are m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unstable Angina
Unstable angina (UA), also called crescendo angina, is a type of angina pectoris that is irregular. It is also classified as a type of acute coronary syndrome (ACS). It can be difficult to distinguish unstable angina from non-ST elevation (non-Q wave) myocardial infarction (NSTEMI). They differ primarily in whether the ischemia is severe enough to cause sufficient damage to the heart's muscular cells to release detectable quantities of a marker of injury (typically troponin T or troponin I). Unstable angina is considered to be present in patients with ischemic symptoms suggestive of an ACS and no elevation in troponin, with or without ECG changes indicative of ischemia (e.g., ST segment depression or transient elevation or new T wave inversion). Since an elevation in troponin may not be detectable for up to 12 hours after presentation, UA and NSTEMI are frequently indistinguishable at initial evaluation. Signs and symptoms Pathophysiology The pathophysiology of unstable angina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anxiety
Anxiety is an emotion which is characterized by an unpleasant state of inner turmoil and includes feelings of dread over anticipated events. Anxiety is different than fear in that the former is defined as the anticipation of a future threat whereas the latter is defined as the emotional response to a real threat. It is often accompanied by nervous behavior such as pacing back and forth, somatic complaints, and rumination. Anxiety is a feeling of uneasiness and worry, usually generalized and unfocused as an overreaction to a situation that is only subjectively seen as menacing. It is often accompanied by muscular tension, restlessness, fatigue, inability to catch one's breath, tightness in the abdominal region, nausea, and problems in concentration. Anxiety is closely related to fear, which is a response to a real or perceived immediate threat (fight or flight response); anxiety involves the expectation of future threat including dread. People facing anxiety may withdraw fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Claudication
Claudication is a medical term usually referring to impairment in walking, or pain, discomfort, numbness, or tiredness in the legs that occurs during walking or standing and is relieved by rest. The perceived level of pain from claudication can be mild to extremely severe. Claudication is most common in the calves but it can also affect the feet, thighs, hips, buttocks, or arms. The word ''claudication'' comes from the Latin ''claudicare'' meaning 'to limp'. Claudication that appears after a short amount of walking may sometimes be described by US medical professionals by the number of typical city street blocks that the patient can walk before the onset of claudication. Thus, "one-block claudication" appears after walking one block, "two-block claudication" appears after walking two blocks, etc. The term ''block'' would be understood more exactly locally but is on the order of 100 metres. Types Intermittent vascular Intermittent vascular (or arterial) claudication (Latin: ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitroglycerin (medication)
Nitroglycerin, also known as glyceryl trinitrate (GTN), is a medication used for heart failure, high blood pressure, anal fissures, painful periods, and to treat and prevent chest pain caused by decreased blood flow to the heart (angina) or due to the recreational use of cocaine. This includes chest pain from a heart attack. It is taken by mouth, under the tongue, applied to the skin, or by injection into a vein. Common side effects include headache and low blood pressure. The low blood pressure can be severe. It is unclear if use in pregnancy is safe for the baby. It should not be used together with medications within the PDE5 inhibitor family such as sildenafil due to the risk of low blood pressure. Nitroglycerin is in the nitrate family of medications. While it is not entirely clear how it works, it is believed to function by dilating blood vessels. Nitroglycerin was written about as early as 1846 and came into medical use in 1878. It is on the World Health Organiza ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sublingual Administration
Sublingual (abbreviated SL), from the Latin for "under the tongue", refers to the pharmacological route of administration by which substances diffuse into the blood through tissues under the tongue. The sublingual glands receive their primary blood supply from the sublingual and submental arteries, which are branches of the lingual artery and facial artery, respectively. These arteries are both branches of the external carotid artery. The sublingual vein drains into the lingual vein, which then flows into the internal jugular system. The sublingual glands receive their parasympathetic input via the chorda tympani nerve, which is a branch of the facial nerve via the submandibular ganglion. The nerve functions in a secretomotor capacity. The chorda tympani branches from the motor branch of the facial nerve in the middle ear cavity, which then exits the middle ear through the petrotympanic fissure. The chorda tympani then travels with the lingual nerve to synapse at the submand ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myocardial Ischemia
Coronary artery disease (CAD), also called coronary heart disease (CHD), ischemic heart disease (IHD), myocardial ischemia, or simply heart disease, involves the reduction of blood flow to the heart muscle due to build-up of atherosclerotic plaque in the arteries of the heart. It is the most common of the cardiovascular diseases. Types include stable angina, unstable angina, myocardial infarction, and sudden cardiac death. A common symptom is chest pain or discomfort which may travel into the shoulder, arm, back, neck, or jaw. Occasionally it may feel like heartburn. Usually symptoms occur with exercise or emotional 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 heart attack. Other complications include heart failure or an abnormal heartbeat. Risk factors include high blood pressure, smoking, diabetes, lack of exercise, obesity, high blood cholesterol, po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
