Heart attack
Sudden interruption or insufficiency of the supply of blood to the heart, typically resulting from occlusion or obstruction of a coronary artery and often characterized by severe chest pain. Also called myocardial infarction.
What is a heart attack?
A heart attack (also known as a myocardial infarction) is the death of heartmuscle from the sudden blockage of a coronary artery by a blood clot. Coronaryarteries are blood vessels that supply the heart muscle with blood and oxygen.Blockage of a coronary artery deprives the heart muscle of blood and oxygen,causing injury to the heart muscle. Injury to the heart muscle causes chest painand pressure. If blood flow is not restored within 20 to 40 minutes,irreversible death of the heart muscle will begin to occur. Muscle continues todie for 6-8 hours at which time the heart attack usually is "complete." The dead heart muscle is replaced by scar tissue.
What causes a heart attack?
Atherosclerosis
Atherosclerosis is a gradual process in which plaques (collections) ofcholesterol are deposited in the walls of arteries. Cholesterol plaques causehardening of the arterial walls and narrowing of the inner channel (lumen) ofthe artery. Arteries that are narrowed by atherosclerosis cannot deliver enoughblood to maintain normal function of the parts of the body they supply
Symptoms of a heart attack include pain and pressure in the chest, which often spread to the shoulder, arm, and neck or even jaw. Today, physicians tend to define heart attack in terms of muscle damage to the heart caused by oxygen deprivation.
Stroke
What is a stroke?
A stroke is the sudden death of brain cells due to a problem with the blood supply. When blood flow to the brain is impaired, oxygen and important nutrients cannot be delivered. The result is abnormal brain function. Blood flow to the brain can be disrupted by either a blockage or rupture of an artery to the brain. There are many causes for a stroke, as shown in the table and discussed below. A stroke is also referred to as a cerebrovascular accident or CVA.
Causes of Stroke
Blockage of artery
Sudden interruption or insufficiency of the supply of blood to the heart, typically resulting from occlusion or obstruction of a coronary artery and often characterized by severe chest pain. Also called myocardial infarction.
What is a heart attack?
A heart attack (also known as a myocardial infarction) is the death of heartmuscle from the sudden blockage of a coronary artery by a blood clot. Coronaryarteries are blood vessels that supply the heart muscle with blood and oxygen.Blockage of a coronary artery deprives the heart muscle of blood and oxygen,causing injury to the heart muscle. Injury to the heart muscle causes chest painand pressure. If blood flow is not restored within 20 to 40 minutes,irreversible death of the heart muscle will begin to occur. Muscle continues todie for 6-8 hours at which time the heart attack usually is "complete." The dead heart muscle is replaced by scar tissue.
What causes a heart attack?
Atherosclerosis
Atherosclerosis is a gradual process in which plaques (collections) ofcholesterol are deposited in the walls of arteries. Cholesterol plaques causehardening of the arterial walls and narrowing of the inner channel (lumen) ofthe artery. Arteries that are narrowed by atherosclerosis cannot deliver enoughblood to maintain normal function of the parts of the body they supply
Symptoms of a heart attack include pain and pressure in the chest, which often spread to the shoulder, arm, and neck or even jaw. Today, physicians tend to define heart attack in terms of muscle damage to the heart caused by oxygen deprivation.
Stroke
What is a stroke?
A stroke is the sudden death of brain cells due to a problem with the blood supply. When blood flow to the brain is impaired, oxygen and important nutrients cannot be delivered. The result is abnormal brain function. Blood flow to the brain can be disrupted by either a blockage or rupture of an artery to the brain. There are many causes for a stroke, as shown in the table and discussed below. A stroke is also referred to as a cerebrovascular accident or CVA.
Causes of Stroke
Blockage of artery
- Clogging of arteries within the brain (e.g. lacunar stroke)
- Hardening of the arteries leading to the brain (e.g. carotid artery occlusion)
- Embolism to the brain from the heart or an artery
- Cerebral hemorrhage (bleeding within the brain substance)
- Subarachnoid hemorrhage (bleeding between the brain and the inside of the skull)
The blockage of an artery in the brain by a clot (thrombosis) is the most common cause of a stroke. The part of the brain that is supplied by the clotted blood vessel is then deprived of blood and oxygen. The cells of that part of the brain die as a result. Typically, a clot forms in a small blood vessel within the brain that has been previously narrowed due to the long-term, damaging effects of high blood pressure (hypertension) or diabetes. The resulting strokes are called lacunar strokes because they look like little lakes. In other situations, usually because of hardening of the arteries (atherosclerosis), a blood clot can obstruct a larger vessel going to the brain, such as the carotid artery in the neck.
Another type of stroke occurs when a blood clot or a piece of atherosclerotic plaque (cholesterol and calcium deposits on the wall of the inside of the heart or artery) breaks loose, travels through open arteries, and lodges in an artery of the brain. When this happens, the flow of oxygen-rich blood to the brain is blocked and a stroke occurs. This type of stroke is referred to as an embolic stroke. For example, a blood clot might originally form in the heart chamber as a result of an irregular heart rhythm, such as occurs in atrial fibrillation. Usually, these clots remain attached to the inner lining of the heart, but occasionally they can break off, travel through the blood stream, form a plug (embolism) in a brain artery, and cause a stroke. An embolism can also originate in a large artery (for example, the carotid artery, a major artery in the neck that supplies blood to the brain) and then travel downstream to clog a small artery within the brain.
Symptoms of a stroke depend on the area of the brain affected. The most common symptom is weakness or paralysis of one side of the body with partial or complete loss of voluntary movement or sensation in a leg or arm. There can be speech problems and weak face muscles, causing drooling. Numbness or tingling is very common. A stroke involving the base of the brain can affect balance, vision, swallowing, breathing and even unconsciousness.
Both of them are medical emergencies. In simple terms, heart attack is the sudden death of heart cells caused due to lack of oxygen supply to heart by a blockage and stroke is sudden death of brain cells due to lack of proper blood supply.
