Electrocardiogram (ECG)
The electrocardiogram (ECG) is the basic test in cardiology. Quick, painless and performed directly at the practice, it records the heart's electrical activity and can detect many abnormalities.
What is an electrocardiogram?
An electrocardiogram (ECG) is a test that examines how the heart is working by measuring its electrical activity. With each heartbeat, an electrical impulse (or "wave") travels through the heart. This wave causes the heart muscle to contract so that it pumps blood out of the heart. An ECG measures and records the electrical activity passing through the heart. A doctor can then determine whether this electrical activity is normal or irregular. An ECG may be recommended if you have an arrhythmia or if you suffer from chest pain or palpitations. Abnormal ECG results can reveal a range of heart problems.
What does it involve?
It can detect arrhythmias that may encourage clots to form; screen for heart problems such as a recent or ongoing heart attack, arrhythmias (irregular heartbeats), blockage of the coronary arteries, damaged areas of the heart muscle (caused by a previous heart attack), enlargement of the heart and inflammation of the membrane surrounding it (pericarditis); detect non-cardiac disorders such as electrolyte imbalances and lung diseases; monitor recovery after a heart attack, the progression of heart disease or the effectiveness of certain medicines or a pacemaker; and rule out heart disease in people awaiting surgery.
How should I prepare?
You do not need to fast before an ECG, although it is recommended not to smoke in the period before the test.
What to expect
An ECG is a painless, non-invasive procedure, which means that nothing is injected into the body. The test does not hurt. Electrodes are attached to various parts of your body, such as the arms, legs and chest, using small suction cups or adhesive patches. Sensors in the electrodes detect the heart's electrical activity. You will usually be asked to lie down for the test. The results take the form of a tracing, which your doctor will interpret. An ECG takes between 5 and 10 minutes.
This information is provided for guidance only and does not replace a medical consultation.