An electrocardiogram (ECG or EKG) is a test that records the electrical activity of the heart. It is a common and painless test 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 electrical signals that make the heart beat. A computer records the information and displays it as waves on a monitor or on paper. An ECG is often done in a health care providers office, a clinic, or a hospital room, and ECG machines are standard equipment in operating rooms and ambulances. Some personal devices, such as smartwatches, offer ECG monitoring.

An ECG is a painless, noninvasive way to help diagnose many common heart problems. It can be used to determine or detect heart rhythm problems, poor blood flow to the heart muscle, heart attack, and other heart-related conditions. An ECG is often the first test done to determine whether a person has heart disease. It is used to help diagnose and monitor many types of heart conditions and their treatment, including arrhythmia, cardiomyopathy, and heart failure.

An ECG is a quick, safe, and painless test that doesn’t hurt. It can be done while lying down and resting or while exercising as part of a stress test. The risks associated with ECG are minimal and rare[[5]](https://www.hopkinsmedicine.org/he...