An electrocardiogram (ECG) is a test that checks for problems with the electrical activity of your heart. An ECG translates the heart’s electrical activity into line tracings on paper. The spikes and dips in the line tracings are called waves.

ECG is done in patients with symptoms such as dyspnoea (difficulty breathing), chest pain (angina), fainting, palpitations, or when someone can feel their own heartbeat is abnormal.  

• An ECG can be used to assess if the patient has had a heart attack or if evidence of a previous heart attack.
• An ECG can be used to monitor the effect of medicines used for coronary artery disease.
• An ECG reveals rhythm problems, such as the cause of a slow or fast heartbeat.
•  For example, to demonstrate thickening of a heart muscle (left ventricular hypertrophy) due to long-standing high blood pressure.
• To see electrolyte imbalance in the blood.