Electrocardiography is a test that measures your heart’s electrical activity. It's quick, painless, and harmless.
The results of that test are shown in an electrocardiogram. It looks like a wavy line with spikes on a grid (a tracing). The electrocardiogram gives doctors information about:
Both the test and the results are referred to as an ECG, sometimes also called an EKG.
You may have an ECG:
As part of a routine checkup, if you're middle-aged or older
As a way for the doctor to evaluate symptoms that could be from a heart problem, such as chest pain Chest Pain Chest pain is a very common complaint. Pain may be sharp or dull, although some people with a chest disorder describe their sensation as discomfort, tightness, pressure, gas, burning, or aching... read more , trouble breathing, a fast or abnormal heartbeat Palpitations Palpitations are the awareness of heartbeats. The sensation may feel like pounding, fluttering, racing, or skipping beats. Other symptoms—for example, chest discomfort or shortness of breath—may... read more , or swelling Swelling Swelling is due to excess fluid in the tissues. The fluid is predominantly water. Swelling may be widespread or confined to a single limb or part of a limb. Swelling is often in the feet and... read more in your legs
Small, round sensors (electrodes) that stick to the skin are placed on your arms, legs, and chest
Wires that snap on to the sensors are connected to a machine
As your heart beats, the sensors measure your heart’s electrical currents
The machine records information from each sensor and develops an ECG (a wavy line with spikes) for your doctor to read
An ECG helps your doctor learn many things about your heart, including: