Key Points

• Holter and event monitors are medical devices that record the heart’s electrical activity.
• Doctors most often use these monitors to diagnose arrhythmias. These are problems with the speed or rhythm of the heartbeat. During an arrhythmia, the heart can beat too fast, too slow, or irregularly.
• Holter and event monitors also are used to detect silent myocardial ischemia. In this condition, not enough oxygen-rich blood reaches the heart muscle. “Silent” means that no symptoms occur.
• These monitors also can check whether treatments for arrhythmia and silent myocardial ischemia are working.
• Holter and event monitors are similar to an EKG (electrocardiogram). An EKG is a simple test that detects and records the heart’s electrical activity. It’s the most common test for diagnosing a heart rhythm problem. However, a standard EKG only records the heartbeat for a few seconds.
• Holter and event monitors are small, portable devices. You can wear one while you do your normal daily activities. This allows them to record your heart for a longer time than an EKG. Holter and event monitors are used to detect heart rhythm problems that may not occur all the time.
• You may need a Holter or event monitor if your doctor suspects you have a heart rhythm problem. Holter or event monitors are most often used to detect these problems in people who have:
  • Fainted or sometimes feel dizzy. A monitor may be used if causes other than a heart rhythm problem have been ruled out.
  • Palpitations that recur with no known cause. Palpitations are the feeling that your heart is pounding, racing, fluttering, or beating unevenly.
• People who are being treated for a heart rhythm problem also may need to use a Holter or event monitor. These monitors can show how treatment is working.
• Your doctor will do a physical exam before giving you a Holter or event monitor. There are many types of Holter and event monitors. Your doctor will help decide which type is right for you.
• Your experience while using a Holter or event monitor depends on the type of monitor you have. Your doctor will tell you how to use your monitor.
• After you’re finished using a Holter or event monitor, you return it to your doctor’s office or the place you got it from. Your doctor will tell you when to expect the results.
• A Holter or event monitor may show what’s causing symptoms of a heart rhythm problem. Holter and event monitors also can show whether a heart rhythm problem is harmless or whether it needs treatment.
• Treatment is needed if the problem causes serious symptoms or increases your chance for complications.
• Holter and event monitors have few risks.