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 A heart attack occurs when the heart muscle fails due to a blockage of a coronary artery. These arteries contain the bloods vessels that give the heart muscles blood and oxygen. Because the heart muscle is unable to receive blood and oxygen is produces chest pains. If within 30 minutes blood flow does not begin irreversible damage will occur to the heart muscle, resulting in scar tissue. Depending on the degree of heart attack, surgery might be an option to repair the scar tissue damage.
What is cholesterol?Cholesterol is a steroid, a lipid, and an alcohol, found in the cell membranes of all body tissues, and transported in the blood plasma of all animals. Most cholesterol is not dietary in origin, it is synthesized internally.Cholesterol is present in higher concentrations in tissues which either produce more or have more densely-packed membranes, for example, the liver, spinal cord, brain and atheroma. Cholesterol plays a central role in many biochemical processes, but is best known for the association of cardiovascular disease with various lipoprotein cholesterol transport patterns in the blood.
LDL cholesterol badLDL cholesterol is also known as the "bad" cholesterol, because excess LDL cholesterol tends to stick to artery walls, which can, in turn, lead to plaque buildup and coronary artery disease, including a heart attack.
The Medical Office of Zarian Mandelblat MD recommends that people without heart disease have LDL levels between 130 160 milligrams per deciliter, depending on their individual risk factors. In some cases LDL of < 100 milligrams per deciliter may be recommended when a person is found to very high risk for a future cardiac problem. For people who have been diagnosed with coronary artery disease, the Medical Office of Zarian Mandelblat MD recommends their LDL. In many cases, these goals may require medication and lifestyle changes.
HDL cholesterol goodHDL, also known as the "good" cholesterol, helps remove excess cholesterol from the blood. An abnormally low HDL level (according to the NCEP, anything below 40 milligrams per deciliter) is considered a risk factor for coronary artery disease.
TriglyceridesTriglycerides – compounds made up of fatty acids and glycerol (a carbohydrate) – bind to proteins to form VLDL, LDL, and HDL. The bloodstream carries these substances to the tissues and stores it for use as future energy. Diet and exercise affect the blood's triglyceride level. Simple sugars – such as fruit juices, alcohol, and sweets -- can dramatically increase triglycerides. The recommended level of triglyceride level is less than 150 milligrams.
VLDLVery low-density lipoproteins (VLDL) carry cholesterol and triglycerides from the liver. After the liver removes triglycerides from it, VLDL becomes LDL.
Normal ArteryThe normal arteries carry blood to the heart muscle. Because the heart muscle is continuously working (as opposed to other muscles of the body, which are often at rest), it has a very high requirement for oxygenated blood. The normal arteries are vitally important for supplying that blood, and allowing the heart to work normally.
The normal heart is able to regulate the amount of blood circulated based on the needs of the tissues. As you exercise, your heart beats faster and squeezes harder to increase the amount of blood delivered for increased needs. The heart regulates itself by receiving input from the nervous system and chemical signals from other tissues in the body.
All of the organs in the body are dependent upon receiving enough blood from the heart. When the heart can't meet the needs of the organs, most people develop symptoms that doctors refer to as "heart failure."
What is atherosclerosis?Atherosclerosis is a disease affecting arterial blood vessels (as well as veins that have been surgically moved to function as arteries). Atherosclerosis typically begins in later childhood, is usually found in most major arteries, yet is asymptomatic and not detected by most diagnostic methods during life. It most commonly becomes seriously symptomatic when interfering with the coronary circulation supplying the heart or cerebral circulation supplying the brain, and is considered the most important underlying cause of strokes, heart attacks, various heart diseases including congestive heart failure and most cardiovascular diseases in general. If atherosclerosis leads to symptoms, the symptoms (such as angina pectoris) can be treated. Medicines are usually the first step in treating cardiovascular diseases, and with improvements, have increasingly become the most effective method over the long term. However, medicines are criticized for their expense, patented control and occasional undesired effects.
What are Glucose and Insulin?Glucose, a monosaccharide, is one of the most important carbohydrates. The cell uses it as a source of energy and metabolic intermediate. Glucose is one of the main products of photosynthesis and starts cellular respiration. The natural form (D-glucose) is also referred to as dextrose, especially in the food industry. Glucose can form from formaldehyde under abiotic conditions, so it may well have been available to primitive biochemical systems. Probably more important to advanced life is the low tendency of glucose, by comparison to other hexose sugars, to non-specifically react with the amino groups of proteins. This reaction (glycosylation) reduces or destroys the function of many enzymes. The low rate of glycosylation is due to glucose 's preference for the less reactive cyclic isomer. Nevertheless, many of the long-term complications of diabetes (e.g., blindness, kidney failure, and peripheral neuropathy) are probably due to the glycosylation of proteins.
Insulin is a polypeptide hormone that regulates carbohydrate metabolism. Apart from being the primary effector in carbohydrate homeostasis, it also has a substantial effect on small vessel muscle tone, controls storage and release of fat (triglycerides) and cellular uptake of both amino acids and some electrolytes. In this last sense, it has anabolic properties. Its concentration (more or less, presence or absence) has extremely widespread effects throughout the body.
Insulin is used medically in some forms of diabetes mellitus. Patients with type 1 diabetes mellitus depend on exogenous insulin (injected subcutaneously) for their survival because of an absolute deficiency of the hormone; patients with type 2 diabetes mellitus have either relatively low insulin production or insulin resistance or both, and a non-trivial fraction of type 2 diabetics eventually require insulin administration when other medications become inadequate in controlling blood glucose levels.
What is type 2 Diabetes?Type 2 diabetes is characterized by "insulin resistance" as body cells do not respond appropriately when insulin is present. This is a more complex problem than type 1, but is often easier to treat, since insulin is still produced, especially in the initial years. Type 2 may go unnoticed for years in a patient before diagnosis, since the symptoms are typically and can be sporadic. However, severe complications can result from unnoticed type 2 diabetes, including renal failure, and coronary artery disease.
Type 2 is initially treated by changes in diet and through weight loss. This can restore insulin sensitivity, even when the weight lost is modest e.g. around 5 kg (10 to 15 lb). The next step, if necessary, is treatment with oral antidiabetic drugs: the sulphonylureas, metformin, or (if these are insufficient) thiazolidinediones. If these fail, insulin therapy may be necessary to maintain normal glucose levels.
How do lipids enter the artery living?Lipids - free fatty acid fractions in the blood. They are stored in the body and serve as an energy source. Elevations can lead to diseases such as heart attack or stroke. Triglycerides - is a type of lipid manufactured by the body from sugars. The recommended blood level is less than 186 mg/dL. This measurement is done by a blood test in a fasting state.
How does plaque reduce blood flow?Plaque is a combination of cholesterol, other fatty materials, calcium, and blood components that stick to the artery wall lining. A hard shell or scar covers the plaque. Plaques have various sizes and shapes. Some plaques are unstable and can rupture or burst. When this happens, it causes blood clotting inside the artery. If a blood clot totally blocks the artery, it stops blood flow completely. This is what happens in most heart attacks and strokes. Too much cholesterol in the blood, damage to the artery wall, and inflammation appear to play important roles in plaque buildup. Researchers are studying why and how the arteries become damaged, how plaque develops and changes over time, and why plaque can break open and lead to blood clots. There may be other factors that prove to be important in causing atherosclerosis.
What causes a heart attack or stroke?Ischemic stroke is usually caused by atherosclerosis (fatty lumps in the artery wall), embolism (obstruction of blood vessels by blood clots from elsewhere in the body), or microangiopathy (small artery disease, the occlusion of small cerebral vessels).
Atrial fibrillation and other arrhythmias can lead to clot formation in the heart, which can become emboli and lodge in the brain. Some forms of thrombophilia (increased coagulation tendency) have a predilection for arterial thrombosis and stroke; these include polycythemia vera and the rare paroxysmal nocturnal hemoglobinuria.
Risk factors (for atherosclerosis and small vessel disease) are advanced age, hypertension (high blood pressure), diabetes mellitus, high cholesterol, and cigarette smoking. High blood pressure is the most important modifiable risk factor of stroke.
Causes of hemorrhagic stroke include hypertension, cerebral AVM, cerebral aneurysms, cerebral arteriosclerosis, head injury, congophilic angiopathy, congenital artery defects and prematurity.
As opposed to hemorrhagic stroke or embolic (or other atherogenic) stroke, watershed strokes occur in parts of the brain that lie at the boundary between zones of arterial distribution from different arteries. When there is hypotension from any cause, these watershed areas are more susceptible to damage than other areas of the brain.
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