What is an ELECTROCARDIOGRAM (ECG)?

The ECG is probably the most basic and first line special investigation done in order to assess the status of a persons heart.

An electrocardiogram, or ECG, records the rhythm and electrical activity of the heart. It may form part of a routine physical examination, depending on the persons age and health history, or it may be performed because of suspected heart disease or before an operation.

How is an ECG performed?

Small electrode patches are placed on the chest, arms and legs. These patches are connected to the ECG recording machine by means of wires. The ECG machine records and measures the electrical signals that are produced by each beat of the heart.

When the machine is turned on, different recordings are made on one strip of paper. These represent the arm, leg or chest recordings, which are used to interpret the total picture.

This procedure is totally pain-free and safe as it merely records the electrical activity of the heart and in no way sends impulses to the body or heart.

How does the ECG assist the clinician with making a diagnosis?

The ECG recording immediately shows any abnormalities in the rhythm of the heartbeat. It will also show if the heart muscle has become enlarged (therefore working under strain) and if there is damage to the heart muscle as in the case of a heart attack.

An ECG can detect heart rhythm problems. It can show whether a patient had a heart attack, either recently or some time ago.

The limitations of an ECG investigation must always be borne in mind and it is important to note that the readings received from an ECG are not absolute. An abnormal ECG does not necessarily always indicate that there is something wrong. In some instances, a normal reading may occur where the patient in fact have serious underlying heart problems.

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