ECG

Electrocardiography (ECG or EKG) is the recording of the electrical activity of the heart over time via skin electrodes.[1] It is a noninvasive recording produced by an electrocardiograph. The etymology of the word is derived from electro, because it is related to electrical activity, cardio, Greek for heart, graph, a Greek root meaning "to write"

Electrical impulses in the heart originate in the sinoatrial node and travel through conducting system to the heart muscle. The impulses stimulate the muscle fibers to contract and thus producing the systole. 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, also understood as vectors. This display indicates the overall rhythm of the heart and weaknesses in different parts of the heart muscle.

Helps In Diagnosis of:

• It is the best way to measure and diagnose abnormal rhythms of the heart,
• Particularly abnormal rhythms caused by damage to the conductive tissue that carries electrical signals, or abnormal rhythms caused by levels of dissolved salts (electrolytes), such as potassium, that are too high or low.
• In myocardial infarction (MI), 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.
• The ECG cannot reliably measure the pumping ability of the heart; for which ultrasound-based (echocardiography) or nuclear medicine tests are used.

Procedure:

You will be brought to the ECG department in the centre. The technician will ask you to take off your clothing from the waist up, put on a gown, and lie down on a small bed. The technician will place a small electrode (a small self-sticking plastic patch) on each of your arms and legs and across six areas on your chest. You need to lie still for the minute or two that it takes the machine to make a record.