Last Review Date: April 5, 2017
The heart consists of two pumps - one that pumps blood around the body from the left side of the heart and one that pumps blood to the lungs from the right side of the heart. The left side of the heart pumps blood through the blood vessels known as arteries, which carry blood with a lot of oxygen in it. After the tissues of the body have collected the oxygen they need, the blood then enters the blood vessels known as veins, which deliver the blood into the right side of the heart. The right side of the heart then pumps the blood to the lungs. In the lungs, the blood receives more oxygen and it goes back to the left side of the heart, where the cycle starts again.
The heart is made of muscle. Like all muscles and other tissues of the body, it needs oxygen. That oxygen is delivered in blood that flows around and into the heart muscle itself from arteries known as the coronary arteries. If a coronary artery is blocked, part of the heart muscle is starved of oxygen. This is known as a heart attack or an acute myocardial infarction (AMI). It may also be called acute coronary syndrome (ACS).
Blockage of the coronary arteries usually happens in people with so-called `hardening' of the arteries (arteriosclerosis or atherosclerosis). Hardening of the coronary arteries is also known as coronary artery disease (CAD) or ischaemic heart disease (IHD). Usually a heart attack occurs when a blood clot forms in a coronary artery that is already partially blocked. The partial blockage, which happens gradually over many years, is usually caused by a build-up of fatty-type material in the wall of the artery.
When a person has a heart attack, the they feel most commonly include a combination of severe chest pain, rapid pulse, breathlessness, nausea, vomiting, dizziness and sweating. However other symptoms are not uncommon and may include pain, pressure, heaviness or tightness in the chest, shoulder(s), neck, arm(s), jaw or back.
If you experience the symptoms of heart attack for 10 minutes, if they are severe or are gettting worse, call Triple Zero (000) immediately and ask for an ambulance. If medical help is not received quickly, the heart muscle may be damaged for the rest of your life. To see the Australian Heart Foundation Warning Signs Action Plan flowsheet (.pdf) click HERE.
Doctors make the diagnosis of a heart attack based on the symptoms and tests such as the and blood tests. The blood tests for a heart attack are tests for chemicals released by the heart muscle when it is damaged. These chemicals, such as troponin (I or T) and CK-MB, can be measured in the blood. These tests should ideally be done in a hospital.
A form of chest pain known as angina is a heart pain in which there is not serious damage like a heart attack, but it is a warning sign that the person has coronary artery disease. Angina occurs during exercise, hard work or at times of stress, lasts for a few minutes and goes away with rest. If the pain lasts longer than a few minutes, especially if it happens when a person is resting, or if the person has been prescribed drugs for angina and they are not working, seek immediate medical attention. Angina and heart attack are both forms of acute coronary syndrome (ACS).
We know a lot about what puts people at higher risk of having a heart attack. A cardiac risk assessment can be used to predict who might be at higher risk of a heart attack in the next five years.
On this site
Tests: Cardiac risk assessment, Troponin, CK, CK-MB, Myoglobin
Conditions: Heart disease, Congestive heart failure, Angina pectoris, Stroke
Elsewhere on the web
healthdirect Australia: Heart attack
Better Health Channel: Heart attack