Electrocardiogram

An electrocardiogram (ECG) measures the rate and rhythm of your heartbeat through small electrodes that are placed on your chest, either while you are lying down (a resting ECG) or during activity (an exercise ECG). An ECG may detect whether your heart is receiving enough blood and whether your heart muscle may have been damaged in the past. Like almost any test, however, an ECG occasionally may not find any problems, even if one is present. This especially may be the case if you have an exercise ECG but feel no symptoms while exercising. Therefore, your healthcare provider may decide to run other tests based on your ECG results.