An electrocardiogram (ECG or EKG) is a simple, painless, and quick test that records the electrical signals in the heart. It is a noninvasive way to help diagnose many common 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. EKGs are mainly used for people who have symptoms of a heart condition or have already been diagnosed with a heart condition. They are 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. An EKG can also be used to check for signs that you have had a previous heart attack that went undetected, an irregular heart rhythm, structural problems within your heart, or artery blockages in your heart.