A myocardial infarction, commonly known as a heart attack, occurs when the arterial blood supply to the heart muscle is blocked off, causing severe damage in the area. Men in general, and people with a family history of heart disease, are more likely to suffer from heart attacks than other people. The risk is further increased with age, high blood pressure, smoking, high blood cholesterol, and obesity. Whether it is mild or acute, a heart attack is a serious medical emergency.
The heart is a big muscle which pumps blood around the body. Like all muscles, the heart needs oxygen to work. This oxygen is brought to the heart by the blood supplied by the coronary arteries. So, the heart muscle has its own blood supply to bring it oxygen.
If one of these coronary arteries that supplies blood to the heart is blocked, the heart cannot obtain a sufficient supply of blood to a part of the heart muscle and this results in it being starved of oxygen (ischaemia) and if this continues for more than a few minutes heart tissue will die.
The arteries may become narrowed by fatty deposits or plaques because the person has high cholesterol levels. These plaques can burst or rupture and then a blood clot can form on the plaque and block the artery.
The severity of the heart attack will depend on the amount of heart tissue that is damaged and where in the heart this damage occurs. A small amount of damage in a vital area may cause death, while considerable damage in a less important area may not be fatal. Angina is another type of heart condition where the blood supply to the heart muscle is reduced considerably but not entirely cut off. Although permanent damage does not occur, angina can lead to heart attack in some cases.
Mild to severe crushing pain is felt in the centre of the chest and may extend to the jaws, back, and arms (usually the left arm). The episodes of chest pain increase.
During an attack a person may also experience breathing difficulties, sweating, dizziness, nausea and vomiting. The person may also have an impending sense of doom and symptoms which include paleness or looking grey, rapid breathing, cold sweat, clammy skin, and may lose consciousness. However, some heart attacks cause only minimal discomfort and are often mistaken for severe indigestion or heartburn.
If you think that someone is having a heart attack, call an ambulance immediately or take them to the emergency department of the nearest hospital. You can use general first aid checks until the ambulance arrives.
It is important to get the person medical help as soon as possible. With each minute that goes by, more heart tissue will be damaged or die, which will affect how well, or whether, the person recovers from the heart attack.
Last Reviewed: 18 March 2003