An ECG is a paper or digital recording of the electrical signals in the heart. It is also called an electrocardiogram or an EKG. The ECG is used to determine heart rate, heart rhythm and other information regarding the heart’s condition. ECGs are used to help diagnose heart arrhythmias, heart attacks, pacemaker function, and heart failure.
The electrocardiogram (ECG or EKG) is a diagnostic tool that is routinely used to assess the electrical and muscular functions of the heart. While it is a relatively simple test to perform, the interpretation of the ECG tracing requires significant amounts of training. Numerous textbooks are devoted to the subject. The heart is a two-stage electrical pump and electrodes placed on the skin can measure the heart’s electrical activity. The electrocardiogram can measure the rate and rhythm of the heartbeat, as well as provide indirect evidence of blood flow to the heart muscle.
EKG leads are attached to the body while the patient lies flat on a bed or table. Leads are attached to each extremity (four total) and to six 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 EKG leads. The leads are attached by small suction cups, Velcro straps, or with small adhesive patches attached loosely to the skin. The test takes about five 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.
Most often, the ECG assessment includes the following:
- determination of the rate,
- assessment of the rhythm,
- evaluation of the electrical conduction patterns. Heart muscle that is irritated conducts electricity differently than heart muscle that is normal. Abnormal conduction may be apparent during ventricular contraction and during ventricular recovery.