A Holter monitor is a small, portable EKG device that records the electrical activity of your heart. Holter monitoring is used for patients whose heart conditions cannot be properly diagnosed through an electrocardiogram (EKG) or other traditional tests. The results of the monitoring are used to diagnose an arrhythmia or myocardial ischemia, conditions that may have no symptoms.
Since an EKG lasts for a few minutes, any heart abnormalities not present at the time of the EKG may not be detected. The Holter monitor, worn for 24 to 48 hours, records the heart's activity throughout that time period. This consistent monitoring may detect arrhythmias that only occur at certain times, such as after physical exertion.
There is no risk involved in using a Holter monitor. While some conditions still may not be diagnosed with this device, you will be asked to keep a list of your activities and any symptoms you may experience. This information is often helpful in identifying the cause of heart rhythm problems.