An electrocardiogram also known as EKG or ECG is a quick, painless, non-invasive test used to monitor your heart.
Each heart beat is generated by an electrical signal generated by SA node in your upper right chamber of your heart. This signal then travels throughout the heart muscle. EKG records these signals and monitors rhythm and heart beats to diagnose certain heart conditions.
Holter and event monitors or ambulatory cardiac monitors or continuous loop event recorders are medical devices that record heart’s electrical activity. When heart’s electrical activity is affected, it results in rhythm disorder called ‘Arrhythmia’. Arrhythmias can be heart muscle beating too fast (tachycardia), beating too slow (bradycardia) or irregular heart beats.
EKG is a simple test that can record heart’s electrical activity. But many a times arrhythmias do not occur at all times. They are sometimes induced by certain activity, physical exertion, sleep or stress. In these cases EKG may miss rhythm disorder. That is when your doctor may order for you to have a holter or event monitor.
Holter and event monitors are small size portable devices that can be worn during daily activities. Holter monitor records the activity for 24-48 hours. Event monitors are similar to holter monitor but only records activity during an ‘event’ when symptoms occur. There are devices that automatically start when the symptoms occur. There are other devices which need to be manually turned on to record the symptoms.
Holter and event monitors also detect ‘silent (no symptoms) myocardial ischemia (lack of oxygen to heart muscle).
Holter and event monitor can also be used to evaluate if a treatment is working for arrhythmia.