Recent advances in digital Holter technology have improved the quality of the ECG signals and new dedicated algorithms have expanded the clinical application of software-based AECG analysis systems.
Holter monitoring is used to help determine whether someone has an otherwise undetected heart disease; such as, an abnormal heart rhythm (cardiac arrhythmia), or inadequate blood flow through the heart.
Specifically, it can detect abnormal electrical activity in the heart which may occur randomly or only under certain circumstances; such as, during sleep or periods of physical activity or stress, which may or may not be picked up by standard, short-term electrocardiography performed in a doctor's office.
There are no known risks associated with Holter monitoring. The main complaint that people have with Holter monitoring is that the monitor may be cumbersome and interfere with certain activities, especially sleeping. Bathing and showering are not allowed during the monitoring period.
The Holter monitoring device is named after Norman J. Holter, D.Sc., a U.S. physicist who is known as "the father" of ambulatory ECG monitoring and recording signals from leads on the chest of a patient and recording them onto magnetic tape for later analysis.
The Holter recorder is quite common and many people with suspected heart problems are instructed to "wear" one for 24 hours during which time the electrodes that are attached to the chest pick up the ECG signals.
The signals are recorded on a cassette tape that runs slowly for a 24 hour recording, then the tape is quickly analyzed by a machine which stops when it detects any abnormalities in the recording.
The electrocardiographic technician, who controls the playback machine, makes notes to report back to a physician.