Heart attack
The death of heart muscle due to the loss of blood supply. The loss of blood supply is usually caused by a complete blockage of a coronary artery, one of the arteries that supplies blood to the heart muscle. Death of the heart muscle, in turn, causes chest pain and electrical instability of the heart muscle tissue. The electrical instability of the heart causes ventricular fibrillation (chaotic electrical disturbances affecting the ventricles, the lower chambers of the heart). Orderly transmission of electrical signals in the heart is important for the regular beating (and the efficient pumping) of the heart. A heart undergoing ventricular fibrillation simply quivers and can not pump or deliver oxygenated blood to the brain. Permanent brain damage and death can occur unless oxygenated blood flow is restored within five minutes. Many heart attack deaths are due to ventricular fibrillation that occurs before the victim can reach any medical assistance or the emergency room. These electrical disturbances of the heart can often be successfully treated with medications or other means by paramedics in the "field," or upon arrival to the hospital. Approximately 90-95% of heart attack victims who reach the hospital survive. The 5-10% who later die are those who have suffered major heart muscle damage, or who suffer an “extension” or enlargement of their heart attack. Early heart attack deaths can be avoided if a bystander starts CPR (cardiopulmonary resuscitation) within five minutes of the onset of ventricular fibrillation. CPR involves breathing for the victim and applying external chest compression to make the heart pump. When paramedics arrive, medications and/or electrical shock (cardioversion) to the heart can be administered to convert ventricular fibrillation to a normal heart rhythm. Therefore, prompt CPR and rapid paramedic response can improve the survival chances from a heart attack. The treatment of a heart attack may include the prompt administration of drugs to dissolve and prevent blood clots; an angioplasty or intracoronary stenting to open an obstructed artery; and medications that open (dilate) blood vessels. Early reopening of a blocked coronary artery reduces the amount of heart muscle damage, lessens the size of the heart attack, and improves prognosis. Patients suffering a heart attack are usually hospitalized for several days to detect heart rhythm disturbance, and observe for shortness of breath and chest pain. A heart attack is also called a myocardial infarction or an MI. Myocardial refers to the myocardium, the heart muscle. Infarction is tissue death due to a local lack of oxygen. For much more on this subject, see the MedicineNet.com article on Heart Attack.

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heart attack n an acute episode of heart disease marked by the death or damage of heart muscle due to insufficient blood supply to the heart muscle usu. as a result of a coronary thrombosis or a coronary occlusion and that is characterized esp. by chest pain called also myocardial infarction compare angina pectoris, coronary insufficiency, heart failure (1)

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1. popular term for myocardial infarction. 2. any of various types of acute episodes of ischemic heart disease.

Medical dictionary. 2011.

Look at other dictionaries:

  • heart attack — heart attacks 1) N COUNT If someone has a heart attack, their heart begins to beat very irregularly or stops completely. He died of a heart attack brought on by overwork. 2) N SING: a N (emphasis) If you say that someone will have a heart attack… …   English dictionary

  • heart attack — heart at.tack n 1.) a sudden serious medical condition in which someone s heart stops working normally, causing them great pain have/suffer a heart attack 2.) give sb/have a heart attack informal to make someone suddenly feel frightened,… …   Dictionary of contemporary English

  • heart attack — heart at,tack noun count * an occasion when someone suddenly has a lot of pain in their chest and their heart stops working: He died of a heart attack. One of the passengers suffered a heart attack …   Usage of the words and phrases in modern English

  • heart attack — heart′ attack n. 1) pat any sudden insufficiency of oxygen supply to the heart that results in heart muscle damage; myocardial infarction 2) pat any sudden disruption of heart function …   From formal English to slang

  • heart attack — ☆ heart attack n. any sudden instance of the blood supply to the heart muscle itself becoming inadequate, resulting in heart muscle damage; esp., CORONARY THROMBOSIS …   English World dictionary

  • heart attack — [n] acute myocardial infarction angina pectoris, cardiac arrest, cardiovascular disease, coronary, coronary thrombosis; concept 308 …   New thesaurus

  • heart attack — ► NOUN ▪ a sudden occurrence of coronary thrombosis …   English terms dictionary

  • heart attack — noun a sudden severe instance of abnormal heart function • Hypernyms: ↑attack, ↑heart failure, ↑coronary failure • Part Meronyms: ↑coronary thrombosis, ↑coronary, ↑myocardial infarction, ↑myocardial infar …   Useful english dictionary

  • heart attack — Pathol. damage to an area of heart muscle that is deprived of oxygen, usually due to blockage of a diseased coronary artery, typically accompanied by chest pain radiating down one or both arms, the severity of the attack varying with the extent… …   Universalium

  • Heart Attack — Filmdaten Deutscher Titel Heart Attack – Die Bombe im Körper Originaltitel Dead in a Heartbeat …   Deutsch Wikipedia

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