A Holter monitor is a small, portable device that continuously records the heart's rhythms and records the electrical activity of the heart. A Holter monitor may be used to capture information and check an individual's heart rhythm if results of other tests, such as an electrocardiogram (EKG), have been inconclusive. The monitor is worn for 24 to 48 hours during normal activity, and it records the heart's electrical activity during that time period.
Because patients are only hooked up to an EKG machine for a short time, it may not detect any irregularities in the heart rhythm. If symptoms suggest that an individual may be experiencing an irregular heart rhythm, a doctor may recommend wearing a Holter monitor for one to two days. Over that time, the Holter monitor may be able to detect irregularities in the heart rhythm that an electrocardiogram was unable to detect. A Holter monitor may also be used to monitor heart rate after a heart attack or to monitor the effectiveness of new heart medication.
How a Holter Monitor Works
Electrodes are stuck on the patient's chest. The electrodes are attached by wires to a small recording monitor. The Holter monitor runs on batteries and is carried in a pocket or pouch worn around the neck or waist. The Holter monitor, worn for 24 to 48 hours and 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. While wearing the Holter monitor, individuals are asked to record any symptoms and activities, so the doctor can link them to the results of the Holter monitor. This information is often helpful in identifying the cause of heart rhythm problems
After the Holter monitor is removed, the doctor will review the results of the test and compare them with any information that the patient recorded while wearing the monitor. A diagnosis may be determined from the results of this test, however in some cases, additional testing may be necessary. There is no risk involved in using a Holter monitor and the test is painless.