An electrocardiogram, which is sometimes referred to simply as an ECG or an EKG, is a diagnostic tool that doctors and medical professionals use to measure a patients heart activity by paying attention to the electric current flowing in the heart. This is a procedure that is fairly routine and is performed all of the time. It generally takes five to ten minutes to do and it is both simple and safe to perform.

For the most part, it is standard for a resting ECG to be administered to patients. A resting ECG takes place when the patient is lying on his or her back and the doctor or technician places metal sensors at the persons wrists, ankles and a number of places in the chest area. The sensors are able to detect the electric impulses of the heart, which are then recorded as special tracings on strips of graph paper. An ECG is not uncomfortable as the current is always coming only from the patient and from nowhere else.

In a general sense a normally beating heart brings about the same pattern of waves in everyone. If this pattern varies at all, it is potentially due to a multitude of problems which could include irregular heart rhythms, which could be a sign of heart disease but is not necessarily so; damage to the muscle of the heart; enlargement of the chambers of the heart; an imbalance of minerals in the blood and finally, whether or not a patient is having or has already had, a heart attack. Most people who show signs of heart disease will find an ECG useful in helping to isolate the problem.

It is important to note that an electrocardiogram is not foolproof. It is possible to have an ECG that is normal but still be afflicted by heart problems. The opposite can also be true - sometimes the graph from the ECG can show problems where there are none at all. Atherosclerosis, which is the buildup of fat in artery walls that causes blocked or narrowed coronary arteries, is not always revealed with a resting ECG due to the fact that when the heart is at rest, it is receiving enough oxygen. In this instance, a doctor may decide that a stress ECG that looks at the condition of the blood vessels of the heart is in order. A stress ECG is done while a patient is either riding a stationary bike or exercising on a treadmill.

A stress test or stress ECG can show signs that there is an inadequate supply of oxygen to specific spots of the heart muscle. The most common case of this problem is narrowing of coronary arteries, which are clogged due to the buildup of plaque. The stress test can uncover problems that would be undetected until a person finds himself or herself suffering from a pain in their chest while they are engaging in physical activity.

Electrocardiograms are most often a routine part of a physical checkup after a person turns forty years old. It is highly recommended that a person have an ECG before they turn forty so later on it can be used for comparison purposes.