The heart is a muscular organ that pumps blood throughout the body via a system of veins and arteries. Blood flows from the lungs, where it picks up oxygen, via the arteries into the heart and gets pumped out to the body, delivering oxygen to the tissues. Then, the de-oxygenated blood returns to the heart via the veins and gets pumped back to the lungs once again completing the cycle. In order to perform these tasks, the heart itself requires large amounts of oxygen that it gets from blood.
An acute myocardial infarction (AMI) – also called a heart attack – may be caused by a blockage in the heart’s arteries that reduces or completely cuts off the blood supply to a portion of the heart. This blockage may be caused by a blood clot that blocks an artery or by a thickening inside the wall of an artery that restricts the flow of blood enough to cause pain and damage. The thickening is usually caused by a build-up of fat.
Symptoms most commonly include a combination of severe chest pain, rapid pulse, breathlessness, nausea, vomiting, dizziness and sweating. However atypical symptoms are not uncommon and may include any of; pain, pressure, heaviness or tightness in your chest, shoulder(s), neck, arm(s), jaw or back with or without some of the other symptoms mentioned.
If you experience the warning signs of heart attack for 10 minutes, if they are severe or get progressivley worse, call Triple Zero (000) immediately and ask for an ambulance. If medical help is not received promptly, irreversible damage to the heart muscle may occur. To see the Australian Heart Foundation Warning Signs Action Plan flowsheet (.pdf) click HERE.
The diagnosis of a heart attack, or other coronary event, may be made by changes in the electrocardiogram (ECG) and by a number of blood tests. This should ideally be carried out in a hospital. When heart muscle is damaged due to lack of blood supply, the cells release chemicals into the blood. These substances, such as CK and troponin, can be measured in blood and provide an indication of heart muscle damage.
The cardiac risk assessment can be used to predict who might be at higher risk for a cardiovascular event within the next five years.