The electrocardiograph (ECG) is a display of the heart's electrical conduction system. It is a starting point in the investigation of many cardiac problems. It is a routine, non-invasive procedure for recording the heart's electrical activity. It is part of your initial physical examination, as well as a monitoring tool in many of the other cardiac investigations.
There is no discomfort involved with an ECG. You will be required to be bare-chested and lie down. For some male patients, a small portion of their chest hair may need to be shaved. The cardiologist or technician will then place some sticky tabs (electrodes) on your chest, wrists and ankles. After the electrodes are in place you will need to lie quietly for a short period whilst the ECG is taken.
There is no preparation required prior to the test.
The end result is a display of 12 waveforms that can be printed or stored on the computer. These waveforms relate to the electrical impulses which occur during each beat of the heart. These electrical impulses travel through specialised cells which form the conduction system of the heart.
The 12 lead ECG enables the cardiologist to examine the conduction system of the heart. When all the waveforms follow the correct order, rhythm is regular and the heart beats between 60 – 100 times per minutes and the heart is said to show normal regular rhythm (Sinus Rhythm).
In many disease states the passage of the electrical signals through the heart are altered. This results in different variations of the recorded waveforms. The variations in the waveforms rate and/or rhythm aid the cardiologist in the detection of cardiac diseases.