Electrocardiography (ECG) is the process of recording the electrical activity of the heart over a period of time using electrodes placed over the skin. These electrodes detect the tiny electrical changes on the skin that arise from the heart muscle's electrophysiologic pattern of depolarizing and repolarizing during each heartbeat. It is very commonly performed to detect any cardiac problems. The diagnosis of acute myocardial infarction is not only based on the ECG. A myocardial infarction is defined as elevated blood levels of cardiac enzymes (CKMB or Troponin T). One of the following criteria are:
The patient has typical complaints.
The ECG shows ST elevation or depression.
pathological Q waves develop on the ECG
A coronary intervention had been performed (such as stent placement)