HOLTER MONITOR
A holter monitor records your heart rate and rhythm during various activities. If a problem or symptom occurs, your monitor will time the symptom. This lets your physician compare the symptom with the heart rate and rhythm during that specific time. The Holter monitor is most helpful when symptoms are frequent. It's also helpful for showing changes in heart rate or rhythm that you may not notice.

How does it work?
A Holter monitor is a small tape recorder connected to wires and several patches called electrodes. These patches are placed on your chest. The tape recorder is located in a small protective box that fits into a case with straps so it can be easily carried on your shoulder or waist.

Electrical impulses produced by a heartbeat travels through the electrodes and wires, and are continuously recorded on tape, usually for a 24-hour period. You will be asked to keep a record of activities in a diary. After the recording has completed, the monitor and electrodes are removed. Then the tape recording is reviewed by a technician using a computer, and the heart rate and rhythm are transferred to paper. Your physician will then review the recorded heart rate and rhythm and compare them with the diary.

EVENT MONITOR
Event monitors are used to record heart rate and rhythms for longer periods. They work only when a person turns on the device.

A event monitor records your heart rate and rhythm during a symptom ("event"). Your physician may recommend an event monitor when symptoms are infrequent - for example, once per week or less.

How does it work?
Event monitors are small, portable devices carried in a purse or attached to a belt or shoulder strap like a portable tape player. When symptoms are infrequent, the monitors may be carried for several days or a few weeks. Most monitors are designed to record the heart rate and rhythm only when a button or switch is turned on. For example, when a symptom occurs, you or another person would turn on the event recorder. The event recorder would then record the heart rate. Then your physician can determine if there was a problem when the symptom occurred

What does this test evaluate?