An electrocardiogram (EKG or ECG) is a test that checks for problems with the electrical activity of your heart. An EKG translates the heart’s electrical activity into line tracings on paper. The spikes and dips in the line tracings are called waves.

An electrocardiogram (EKG or ECG) is done to:

Check the heart’s electrical activity.
Find the cause of unexplained chest pain, which could be caused by a heart attack, inflammation of the sac surrounding the heart (pericarditis), or angina.
Find the cause of symptoms of heart disease, such as shortness of breath, dizziness, fainting, or rapid, irregular heartbeats (palpitations).
Find out if the walls of the heart chambers are too thick (hypertrophied).
Check how well medicines are working and whether they are causing side effects that affect the heart.
Check how well mechanical devices that are implanted in the heart, such as pacemakers, are working to control a normal heartbeat.
Check the health of the heart when other diseases or conditions are present, such as high blood pressure, high cholesterol, cigarette smoking, diabetes, or a family history of early heart disease.