An ambulatory electrocardiogram (EKG or ECG) records the electrical activity of your heart while you do your usual activities. (Ambulatory means that you are able to walk.) Ambulatory monitors are referred to by several names, including ambulatory electrocardiogram, ambulatory EKG, Holter monitoring, 24-hour EKG, or cardiac event monitoring.
Many heart problems become noticeable only during activity, such as exercise, eating, sex, stress, bowel movements, or even sleeping. A continuous 24-hour recording is more likely to detect any abnormal heartbeats that occur during these activities.
Many people have irregular heartbeats (arrhythmias) from time to time. The importance of irregular heartbeats depends on the type of pattern they produce, how often they occur, how long they last, and whether they occur at the same time you have symptoms. Because arrhythmias can occur off and on, it may be hard to record an arrhythmia while you are in the doctor’s office.
There are several different types of ambulatory monitors. Your doctor will choose the type that is most appropriate for you and is most likely to help diagnose your heart problem.