What is an electrocardiogram?

An electrocardiogram (ECG) is a non-invasive (meaning it does not require an incision into the body) test that records the electrical activity of the heart. The electrical activity is related to the impulses that travel through the heart that determines the heart rate and rhythm. These electrical impulses, which cause your heart to contract and relax, are detected by an electrocardiographic machine and are transformed in the form of waves that can be displayed on a graph or monitor.

This test helps the doctor evaluate the patient's cardiac condition, such as to detect if there are any irregular heart rhythms or abnormal ECG morphology.