Electrocardiography (ECG ) is the process of recording the electrical activity of the heart over a period of time using electrodes placed on 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 a very commonly performed cardiology test.
The overall goal of performing electrocardiography is to obtain information about the structure and function of the heart. Medical uses for this information are varied and generally relate to having a need for knowledge of the structure and/or function. Some indications for performing electrocardiography include:
- Suspectedmyocardial infarction (heart attack) or new chest pain
- Suspected pulmonary embolism or new shortness of breath
- A third heart sound, a or other findings to suggest structural heart disease
- Perceived cardiac dysrhythmias palpitations
- Monitoring of known cardiac dysrhythmias
- Fainting or collapse
- Seizures
- Monitoring the effects of a heart medication (e.g. drug-induced QT prolongation)
- Assessing severity of electrolyte abnormalities, such as hyperkalemia
- Hypertrophic cardiomyopathy screening in adolescents as part of a sports physical out of concern for sudden cardiac death (varies by country)
- Perioperative monitoring in which any form of anesthesia is involved (e.g. monitored anesthesia care, general anesthesia); typically both intraoperative and postoperative
- Cardiac stress testing
- (CTA) and Magnetic resonance angiography (MRA) of the heart (ECG is used to “gate” the scanning so that the anatomical position of the heart is steady)
- Biotelemetry of patients for any of the above reasons and such monitoring can include internal and external defibrillators and pacemakers
