What is an Electrocardiogram (ECG)?

An electrocardiogram (ECG) is one of the simplest and fastest procedures used to evaluate the heart. Electrodes (small, plastic patches) are placed at certain locations on the chest, arms, or legs. When the electrodes are connected to an ECG machine by lead wires, a graphic representation, or tracing, of the electrical activity can be obtained. This electrical activity is measured, interpreted, and printed out for the doctor’s information and further interpretation.
This type of ECG usually takes five to 10 minutes to complete and is a safe procedure with no known risks. It’s completely painless and non-invasive, as the skin is in no way penetrated and no electric current is sent to the body. On occasion the patient may be allergic or sensitive to the electrodes causing local skin reddening.

Why is an Electrocardiogram (ECG) performed?

An electrocardiogram (ECG) is performed as part of a routine physical examination or screening evaluation. Some of the various heart problems that can be diagnosed by ECG include:

  • Enlargement of the heart
  • Congenital heart defects involving the conducting (electrical) system
  • Abnormal rhythm (arrhythmia) – rapid, slow or irregular heart beats
  • Damage to the heart such as when one of the heart’s arteries is blocked (coronary occlusion)
  • Poor blood supply to the heart
  • Abnormal position of the heart
  • Heart inflammation – pericarditis or myocarditis
  • Cardiac arrest during emergency room or intensive care monitoring
  • Disturbances of the heart’s conducting system
  • Imbalances in the blood chemicals (electrolytes) that control heart activity.