The electrocardiogram (ECG or EKG) is a noninvasive test that is used to reflect underlying heart conditions by measuring the electrical activity of the heart. By positioning leads (electrical sensing devices) on the body in standardized locations, information about many heart conditions can be learned by looking for characteristic patterns on the ECG.
ECG leads are attached to the body while the patient lies flat on a bed or table. Leads are attached to each extremity (4 total) and to 6 pre-defined positions on the front of the chest. A small amount of gel is applied to the skin, which allows the electrical impulses of the heart to be more easily transmitted to the ECG leads. The leads are attached by small suction cups, Velcro straps, or by small adhesive patches attached loosely to the skin. The test takes about 5 minutes and is painless. In some instances, men may require the shaving of a small amount of chest hair to obtain optimal contact between the leads and the skin.