An ECG (electrocardiogram) records the electrical activity of your heart at rest. It provides information about your heart rate and rhythm, and shows if there is enlargement of the heart due to high blood pressure (hypertension) or evidence of a previous heart attack (myocardial infarction). However, it does not show whether you have asymptomatic blockages in your heart arteries or predict your risk of a future heart attack. The resting ECG is different from a stress or exercise ECG or cardiac imaging test. You may need an ECG test if you have risk factors for heart disease such as high blood pressure, or symptoms such as palpitations or chest pain.
In some cases, it can be important to get this test. You should probably have an ECG if you have risk factors for an enlarged heart such as high blood pressure or symptoms of heart disease, such as chest pain, shortness of breath, an irregular heartbeat or heavy heartbeats. You may need the test for screening or occupational requirements, or if you have a personal or family history of heart disease, diabetes or other risks and you want to start exercising.