A heart attack (also known as myocardial infarction) occurs when there is a sudden obstruction of blood flow in the coronary artery.

The heart is a fist-size organ which lies in the centre of the chest. Its main function is to pump blood to the lungs where the blood is replenished with oxygen and then subsequently to pump blood to the rest of the body to allow it to function properly. In order for the heart itself to function properly, it receives blood rich with oxygen via blood vessels called coronary arteries.