An electrocardiogram (ECG or EKG) is a routine test that is used to look at the electrical activity of the heart. An EKG can tell your doctor about your heart's rate and rhythm. This test can help your doctor learn more about your heart rhythm, the size and function of the chambers of your heart, and your heart muscle. A healthy person’s EKG has a certain pattern. When there are changes in that pattern, your doctor can tell that there is a problem with your heart. For example, during a heart attack, the EKG machine records the changing pattern of the heart’s electrical activity that indicates poor blood flow to a portion of your heart. An EKG is usually performed at each office visit with your provider.
For your heart to beat, an electrical impulse is sent from the sinoatrial (SA) node, which is located in your heart. An electrocardiogram can trace the path of electrical energy that is sent from the SA node and through your heart to the AV node and then throughout the heart muscle. This lets your doctor know whether you have a problem that might cause your heart to beat irregularly.
For example, small metal disks called electrodes are placed on your skin. The electrodes are used to pick up the electrical impulses of the heart. The impulses are recorded giving doctors a record of your heart’s electrical activity when printed onto special paper.
During the test, you will lie on an examination table. A technician will clean the areas on your chest where the electrodes will be placed. The electrodes have wires called leads, which hook up to the electrocardiogram machine.
Once the electrodes are in place, you will be asked to lie still. The EKG machine will send the electrical activity and the technician will save this over a few seconds time. The test is completely safe and painless.