A heart attack or myocardial infarction (MI for short) is the result of interruption to the blood supply to the heart.
If a thrombus blocks an artery which supplies blood to the cardiac muscle (a coronary artery), a life-threatening heart attack can occur. The heart muscle works continuously to pump blood around the body requires a constant supply of oxygen-rich blood to nourish it. The coronary arteries provide the heart with this critical blood supply. If the blocked artery is not reopened within a few hours, the consequence is the death of cardiac muscle cells. The resultant scars which form in the muscular tissue can interfere with electrical conduction and so have a negative effect on the ability of the heart to contract.
Typical signs of a heart attack are a sudden onset of pain in the middle of the chest and/or behind the chest bone, pain in the back and arms and breathing difficulty. Additional symptoms that sometimes occur are cold sweats, nausea, vomiting, and loss of consciousness.
A heart attack is a medical emergency that requires immediate medical attention.