What is ECG ? What are its Functions?

Asked by padminik | 24th Mar, 2009, 04:45: PM

Expert Answer:

Electrocardiography (ECG or EKG) is a test that records the electrical activity of the heart over time via skin electrodes. It is a noninvasive recording produced by an electrocardiograph.


Electrical impulses in the heart originate in the sinoatrial node and travel through the heart muscle where they impart electrical initiation of systole or contraction of the heart. The electrical waves can be measured at selectively placed electrodes (electrical contacts) on the skin. Electrodes on different sides of the heart measure the activity of different parts of the heart muscle. An ECG displays the voltage between pairs of these electrodes, and the muscle activity that they measure, from different directions.



An ECG is used to measure:

  • any damage to the heart and weaknesses in different parts of the heart muscle
  • how fast your heart is beating and whether it is beating normally
  • the effects of drugs or devices used to control the heart (such as a pacemaker)
  • the size and position of your heart chambers
  • and diagnose abnormal rhythms of the heart

An ECG is a very useful tool for determining whether a person has heart disease. Your doctor may order this test if you have chest pain or palpitations. An ECG may be included as part of a routine examination in patients over age 40. In myocardial infarction, the ECG can identify damaged heart muscle. But it can only identify damage to muscle in certain areas, so it can't rule out damage in other areas.

Answered by  | 25th Mar, 2009, 10:27: AM

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