An electrocardiogram (ECG or EKG) is a simple, painless, and quick test that records the electrical signals in the heart. It is a common and non-invasive test used to quickly detect heart problems and monitor the hearts health. EKG machines are standard equipment in operating rooms and ambulances, and some personal devices, such as smartwatches, offer EKG monitoring.

During an EKG, up to 12 sensors (electrodes) are attached to the chest and limbs, which are sticky patches with wires that connect to a monitor. The electrodes record the hearts electrical signals, which cause the heart to beat, and a computer records the information and displays it as waves on a monitor or on paper. The test is painless and non-invasive, and it can be done while lying down and resting or while exercising as part of a stress test.

An EKG is a "snapshot" of the hearts activity over a very short time, so it is mainly used for people who have symptoms of a heart condition or have already been diagnosed with a heart condition. It is not generally used to screen people who dont have symptoms unless they have an increased risk of developing heart disease. An EKG test is used to help diagnose and monitor many types of heart conditions and their treatment, including arrhythmia, cardiomyopathy, and heart attack.

In summary, an EKG is a simple and non-invasive test that records the electrical signals in the heart to help diagnose and monitor many types of heart conditions and their treatment.