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25 years
What is cause MI
Aug 18, 2014

Dr. Rania Mousa General Medicine
MI or a myocardial infarction, commonly known as a heart attack, is a medical emergency that occurs when a portion of the heart is deprived of oxygen because of blockage of one of the coronary arteries, which supply the heart muscle (myocardium) with blood. Lack of oxygen causes characteristic chest pain and death of myocardial tissue.

The process of atherosclerosis, or buildup of plaque on arterial walls which causes clotting, may be halted or even reversed with fairly simple measures to reduce the risk of heart attack. If treatment is received within a few hours of the onset of a heart attack, chances for survival are good. However, prompt emergency medical attention is crucial.

CAUSES ARE :

>Heart attacks are more likely to occur when arteries have already been substantially narrowed by years of coronary artery disease(the arteries of the heart ).
In a process known as atherosclerosis, plaque (which is composed of cholesterol-rich fatty deposits, collagen and other proteins, and excess smooth muscle cells) builds up in the arterial walls, causing those walls to thicken and narrow, inhibiting the flow of blood into the heart.

>Plaque deposits roughen arterial walls, making it much easier for blood clots to form along the surface of the plaque.
If the clots grow, or if they detach from their place of origin and are carried along to a narrower section of artery, they may block a coronary artery completely, causing a heart attack.

>Arteries may also narrow suddenly as a result of an arterial spasm.

> age (heart attacks most commonly occur after age 65) in both men and women

>gender ,men have a significantly higher risk of heart attack than pre-menopausal women. The risk for postmenopausal women approaches that of men as estrogen production decreases with menopause.

> cigarette smoking,nad other smoke

>high blood pressure

>high blood cholesterol levels

> a diet rich in saturated fat (especially animal fat)

>obesity, lack of exercise and diabetes mellitus.

>A family history of early or premature heart attacks (before the age of 55 in men and 65 in women) increases the risk of heart attack.

>A spasm of the muscles of the arterial walls may cause a heart attack by narrowing an artery. Spasms may be triggered by smoking, extreme emotional stress, or exposure to very cold air or water.

>Abuse of cocaine or amphetamines may cause a sudden heart attack even in those with no signs of heart disease.
>Heavy exertion, such as shoveling snow or carrying heavy objects up stairs, and severe emotional stress may trigger a heart attack.

>Having had one heart attack increases the risk of future heart attacks.

However ,time is critical during treatment of heart attack. Most heart attack deaths result from an abnormal heart rhythm during delays in reaching the hospital,The longer the time from the onset of a heart attack to re establishing blood flow to the heart, the more permanent heart damage can occur.
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