Event Monitor versus Mobile Cardiac Telemetry?
Event Monitor or Mobile Cardiac Telemetry (MCT or MCOT) is a common topic of discussion today among cardiovascular specialists. Many question when it is appropriate to order a traditional patient activated Event Monitor or Mobile Cardiac Telemetry (MCT). Mobile Cardiac Telemetry remains a relatively new form of ambulatory monitoring that has substantial technological advantages over traditional looping Event Monitors.
An Event Monitor has been a traditional electrocardiographic diagnostic tool for Cardiologists dating back to 1980. The use of an Event Monitor is intended to capture a symptomatic event that is too infrequent to capture with a continuous 24 hour Holter Monitor. Event Monitors have proven to be useful in that they capture only the EKG information at the time the symptom occurs. However, if there is no relevant EKG captured, the study may not be useful.
There are several types of Event Monitor technologies available. These include:
- Non-Continuous ‘memory loop” Event Monitors
- Auto-Trigger Event Monitors
- Implantable ‘continuous’ Event Monitors
- Implantable ‘looping” Event Monitors
- Mobile Cardiac Telemetry (MCT) monitoring
Most practicing Cardiology specialists commonly use the “memory loop” Event Monitors and Mobile Cardiac Telemetry (MCT) monitoring. These are the most common diagnostic tools used for long term cardiac monitoring. Both have similar indications but there is more.. Mobile Cardiac Telemetry is perceived to be much more expensive in use as compared to traditional ‘memory loop’ symptomatic monitoring. The industry pioneer CardioNet argues that their Mobile Outpatient Telemetry (MCOT®) devices are more effective in detecting cardiac rhythm abnormalities (compared to ‘looping’ event) while simultaneously lowing the cost of care for these patients.
So when should an Event Monitor versus Mobile Cardiac Telemetry (MCT or MCOT) be ordered?
We can start by evaluating the definitions:
The use of patient activated or auto-activated external ambulatory event monitors is deemed medically necessary as a diagnostic alternative to Holter Monitoring in the following situations:
- Patient who experience infrequent symptoms (less frequent than 48 hours) suggestive of cardiac arrhythmias (palpitations, dizziness, pre-syncope, or syncope)
- Patients with Atrial Fibrillation who have treated with catheter ablation, and in who discontinuation of systemic anti-coagulation is being considered
For Medicare Advantage, cardiac event detection involving the use of a long term monitor by a patient which includes event monitors and Mobile Cardiac Telemetry is considered medically necessary for:
- Detection, characterization, and documentation of symptomatic transient arrhythmias when the frequency of the symptoms is limited and use of 24 Holter Monitoring is unlikely to capture and document the arrhythmia;
- Regulation of anti-arrhythmic medication dosages, when needed to assess efficacy of treatment
- To Monitor patients who have had surgical or ablative procedures for arrhythmias
These appear to be clear definitions for the use of each type of long term monitoring. As a general rule, it is best practice to adhere to the guidelines of use with the exception of the following:
- Technological limitations of patient activated symptomatic event monitoring such as sleep
- Patient interaction / compliance is questionable
- Technical ability to perform download
- Mental mind state to keep up with performing tasks
- Potentially longer study for patient than one that captures & transmits automatically
Keep in mind, Medicare pays much more for Mobile Cardiac Telemetry compared to the Event Monitor. With that being the case, it is important to have substantial evidence of why you would order MCT over other forms of traditional event monitors.