An electrocardiogram (ECG or EKG) is a test that records the electrical signals in the heart to check for different heart conditions. It is a common and painless test that is used to quickly detect heart problems and monitor the hearts health. During an ECG, up to 12 sensors (electrodes) are attached to the chest and limbs, which record the hearts electrical signals that cause the heart to beat. The signals are shown as waves on an attached computer monitor or printer. An ECG is a quick, noninvasive test that doesn’t hurt and can be done in a health care providers office, a clinic, or a hospital room. ECG machines are standard equipment in operating rooms and ambulances, and some personal devices, such as smartwatches, offer ECG monitoring.

An ECG is used to help diagnose and monitor many types of heart conditions and their treatment, including arrhythmia, cardiomyopathy, and heart attack. It is also used to look for the cause of chest pain, evaluate problems that may be heart-related, identify irregular heartbeats, and get a baseline tracing of the hearts function during a physical exam. An ECG is a "snapshot" of your hearts activity over a very short time, so it may not pick up irregularities that only happen once in a while. If you have heart symptoms that come and go, your provider may recommend that you wear a small portable EKG.

To perform an ECG, up to 12 sensors (electrodes) are attached to the chest and limbs, and the electrodes are sticky patches with wires that connect to a monitor. The test is quick, safe, and painless, and it can be done while...