Unfortunately heart attack is a very frequent situation and it affects about 1 million people in the U.S. annually; and kills almost a half of them.

Another name for a heart attack is a myocardial infarction. This is a very serious condition that occurs when a coronary artery is abruptly blocked by a blood clot in the result of which heart muscle dies. Coronary arteries are responsible for the process of supplying the heart muscle with blood and oxygen. In the situation when this very artery becomes blocked no blood and no oxygen in the necessary amounts can reach the heart muscle and it becomes injured. Furthermore it causes chest pain and the sensation pf pressure. Time for recovery of the heart muscle in this situation is very short – only 20-40 minutes during which the blood flow should be restored; otherwise the heart muscle starts to die and this process is irreversible. After six-eight hours is will be completely dead and replaced by scar tissue.

There are some preconditions for the this to happen. Atherosclerosis is one of them. This is the condition caused by the hardening of the arterial channels and their blockage with cholesterol plaques. In the result it is hard for these narrowed arteries to provide a normal blood flow in the body. Atherosclerosis that affects the brain may lead to vascular dementia or stroke; atherosclerosis that affects legs is fraught with pain while walking or exercising, also leg ulcers, or problematic healing of leg injuries.

Atherosclerosis will not necessarily show up at once and a person can be oblivious of it for years. The condition can start in early teens but actual symptoms show up later with aging and development of atherosclerosis. There are factors that can impair the condition; among them are high cholesterol, hypertension, smoking, diabetes. They are able to considerably complicate the existing state; especially this concerns people with a family history of atherosclerosis.

Coronary atherosclerosis, another name is coronary artery disease, is also able to cause heart failure. This is a type of atherosclerosis that affects coronary arteries and evokes illnesses that can be generally called coronary heart diseases, or CHD (i.e. angina, heart attack, sudden unexpected death, arrhythmia, and, actually, heart failure).

Angina (angina pectoris, chest pain) should be paid additional attention. It happens when there is not enough oxygen and blood supplied to the heart muscle which causes the sensations of pressure and pain. There are differentiated exertional and rest anginas.

Cholesterol plaque may tear a coronary artery surface then a blood clot appears on the surface of the plaque. This leads to a blockage of the blood flow and ends up with a heart attack. Why the tear happens and a clot appears is not known for sure but some researches list smoking or other nicotine exposure, high adrenaline, hypertension and some other mechanical and biochemical forces are probable reasons.

Heart attacks are mostly known to happen between 4:00 and 10:00 in the morning due to the higher blood adrenaline levels released from the adrenal glands at this time. As much as half of the patients who happen to experience a heart attack generally received some warning signals before the attack but due to their mildness and indefinite character they are frequently are not taken into consideration.