An electrocardiogram (ECG) is a recording of the electrical events associated with each cardiac cycle. An ECG shows how fast your heart is beating, whether the rhythm of your heartbeat is steady or irregular, and the strength and timing of electrical signals as they pass through each part of your heart. Such information can help you understand the general health of your heart and be used to discover or prevent different types of heart disease you may have. It is the best tool to help diagnose Arrhythmia.
There are a variety of ECG machines and devices available that offer different types of ECG tests. 12-Lead ECG, Exercise ECG, and Event Monitoring ECG are often used in hospitals, and for more portable needs or long term monitoring, 24-hour ECG (Holter) and Portable ECG are the most common type of ECG devices. They all work basically the same way and perform the ECG tests that look for heart rate abnormalities. The main difference between them is found in the amount of information they gather, the way they process the information and display the results, their portability, and their usability features.