Home Cardiac Monitoring Technologies: A Comparison
December 14, 2016 | Evaluations & Guidance
For patients with a suspected cardiac condition, a physician may decide that one or more types of home cardiac monitoring might be useful in diagnosis. The most frequently used types of monitors are:
Holter monitor. An ambulatory ECG monitor that uses between 3 and 12 leads. The patient wears the electrodes and an attached electronic recording device for the duration of the study, which is typically between 24 and 48 hours. Data is recorded continuously and is analyzed once the recorder is returned at the end of the study.
Event monitor. Similar to a Holter monitor, except that instead of recording one to two days of continuous data, it is worn for a longer time (up to several weeks) and only records data when an event occurs. Event triggering can be automatic (using an algorithm in the recording device), patient-initiated (typically with a button), or both. Recorded events can include a window of time before and after the trigger occurs. Typically, event monitors store fewer than 10 events. Recorded events may be sent to a physician or ECG technician for immediate analysis or transmitted daily via a telephone line, cellular connection, or the Internet.
Loop recorder. A term usually used to describe a type of event monitor that is implanted next to the patient's heart. These devices record continuously on a relatively small amount of memory, overwriting data as needed. The system has two elements: the implanted monitor and a bridge device that communicates wirelessly with the monitor. When an event is detected, either by an automatic algorithm or by patient activation (using the bridge device), the system captures the current data as well as data from a few minutes before and after the event. Data is downloaded from the implanted device to the bridge device, which passes the data to the clinician via telephone, cellular connection, or Internet. One common setup is to have the bridge device at the patient's bedside so any captured loops can be automatically downloaded from the loop recorder every night and sent to the clinician. Loop recorders have to be explanted at the end of the study period.
In addition to these traditional techniques, two newer...