Myocardial infarct

Myocardial Infarction means the destruction of myocardial cells due to a lack of oxygen.

If the myocardial cells are not supplied the necessary oxygen to meet their metabolic demands, then they die.

Thus, a myocardial infarct (a heart attack) occurs when there is not enough oxygen being supplied by the flow of blood.

There are two main reasons why there would be oxygen insufficieny.

Number One: If the heart increases its work load, it needs more energy, thus it increases its metabolic demands, and if the blood can not flow fast enough or in enough quantify (essentially the same thing) then there will be greater demand for oxygen than there is supply. If this last long enough, the cells will die. An example of this is someone, out of shape, who goes running and the heart speeds up, but altought it has an increased metabolic demands, they can not be met, and thus a heart attack can occur.

Number Two. If the metabolic demands of the heart remain the same, but the supply of blood is suddently cut off, this will also result in myocardial infarction. In this case, although there is stilla greater demand for blood than supply, the reason for this is that the coronary arteries have been clogged, by a thrombus or suddenly closed off plaque

Health Sciences > Medicine > Cardiology