This test is the most basic and generally takes place in your doctor’s office, where a healthcare professional places electrodes on your wrists, ankles, and chest for a few minutes to record your heart’s electrical activity. The test does not hurt. The timing and duration of the electrical phases of your heartbeat are recorded. The doctor studies the three waves that appear on the ECG. Each wave represents a different part of the heartbeat and tells the doctor about your heart and its rhythm. This test shows a snapshot of your heart’s electrical activity.