BlueCross and BlueShield of Montana Medical Policy/Codes
Ambulatory Cardiac Event Monitors (AEMs or CEMs) including Mobile Cardiac Outpatient Telemetry (MCOT)
Chapter: Medicine: Tests
Current Effective Date: December 27, 2013
Original Effective Date: August 14, 2008
Publish Date: September 27, 2013
Revised Dates: March 16, 2011; September 13, 2013

Cardiac rhythm abnormalities (changes in the heartbeat rhythm) are common.  Although many arrhythmias are not harmful, some can cause symptoms and thus the detection and quantification of these arrhythmias becomes important.  Generally, arrhythmias are frequently limited in duration and occurrence and cannot be detected during a routine electrocardiography (EKG), because this procedure permits only a few seconds of cardiac rhythm observations.  To diagnose arrhythmias and to assess their relationship to the patient's symptoms, longer periods of EKG observations are required while the patient is pursuing their normal activity/routine.

External Holter Monitoring (HM):

Ambulatory HM is a widely used noninvasive test in which the EKG is continuously recorded over an extended period of time (typically 24- to 48-hours).  This is done in order to evaluate symptoms suggestive of cardiac arrhythmias, such as palpitations, dizziness, or syncope.  However, HM is ineffective if a patient experiences infrequent symptoms.

Recently, newer forms of ambulatory HM’s are available to record continuous EKG data.  In 2009, the U.S. Food and Drug Administration (FDA) approved the Zio® EKG Utilization Service (ZEUS) System, by iRhythm Technologies, Inc., also known as the “simple EKG monitoring” utilizing a simple patch system.  The ZEUS system analyzes received EKG data captured by a long-duration, single-lead, continuous recording on the single use Zio® Patch and Zio® Continuous Card.  The ZEUS system uses beat-by-beat QRS detection (heart rate measurement) and a rhythm analysis algorithm to detect up to ten categories of rhythms.  ZEUS can be used to analyze up to 14-days of EKG data.  The system does not contain diagnostic interpretation.  The ZEUS system is ordered for patients who are asymptomatic or may experience transient symptoms such as pre-syncope, syncope, palpitations, shortness of breath, dizziness, lightheadedness, fatigue or anxiety. 

External Real-Time or External Delayed Time Monitoring (AEM) including Implantable Continuous Monitoring (ICM):

AEMs were developed to provide longer periods of monitoring (greater than 48-hours), which is done to evaluate symptoms of cardiac arrhythmias or other cardiac events, such as implanted defibrillator discharge or transient arrhythmias.  AEMs may be used to manage cardiac treatment, such as regulation of antiarrhythmia drug therapy or post myocardial infarction monitoring.  In this technique, the recording device is worn continuously and activated only when the patient experiences symptoms, OR it is carried by the patient and activated when symptoms occur. There are two types of retrieved information; real-time monitoring and delayed-time monitoring.

  • When real-time (instantaneous/constant) monitoring is used, the EKG is immediately received via wireless telephonic or electronic messaging to a cardiac monitoring service or a mobile personal computer link or work station.  The EKG is instantly monitored and evaluated, OR it is stored for future evaluation of the potentially serious/life-threatening events.  These devices are miniature, pocket sized versions of the standard EKG machine known as pocket electrocardiography (PECG), which is part of the revolution of micro-electronic or pocket medicine.  The patient has 12 leads placed on their body, which is attached to a palm-pilot or other pocket personal computer platform type of EKG device.  The device transmits the data instantaneously via mobile phone or other wireless networks for viewing by medical personnel.  The United States Food and Drug Administration (FDA) has cleared PocketView-ECG® and PocketView-EKG® in January 2002 for marketing. 
  • When delayed-time (historical/memory) monitoring is used, the recorded EKGs are either stored for future analysis or transmitted by telephone to a receiving station, such as a doctor's office, hospital, or to a cardiac monitoring service.  Delayed-time AEMs are not considered a substitute for conventional methods of diagnosis, such as a careful history and physical examination, standard EKG and rhythm strip(s).  Several different types of delayed-time AEMs are available:
    1. EXTERNAL NON-CONTINUOUS DEVICES WITH MEMORY: These devices are carried by the patient and applied to the sternum or chest directly in front of the heart via non-gel electrodes while the cardiac symptoms or events are occurring or a recording device may be worn at the wrist and then activated when symptoms/events are present.  The limitation of these devices is that an arrhythmia of very short duration would be difficult to record.  In addition, non-continuous devices require reasonable dexterity on the part of the patient to apply the device correctly during a symptomatic period.
    2. EXTERNAL CONTINUOUS MEMORY LOOP DEVICES:  These sophisticated devices are able to continuously record a single channel of EKG data in a refreshed memory.  The EKG runs and records continuously in the memory loop.  When the patient activates the device to mark the symptom or event, the preceding 30 to 90 second (and for the next minute or so after the event) recording is stored in the permanent memory.  Otherwise, the remainder of the recordings in the temporary memory is automatically or manually discarded.  Therefore, these types of devices permit recording of the onset of arrhythmias and/or transient or incapacitating events.  These devices are worn and run continuously.
    3. IMPLANTABLE CONTINUOUS MEMORY LOOP DEVICES: An implantable loop recorder device is inserted just under the patient's skin in the chest area during an outpatient surgical procedure.  When symptoms are felt, the patient places a hand-held activator over the recorder to activate the storage of cardiac rhythms.  This device can be used for more than one year.
    4. AUTO-TRIGGERED DEVICES:  All of these devices described above require activation by the patient.  More recently, auto-triggering technology has become available, which can be adapted to memory loop devices.  For example, AEMs can be programmed to detect heart rates greater than 165 beats per minute, less than 40 beats per minute, or an asystole (no detectable beating) of greater than three seconds. 

NOTE:  Real- or delayed-time AEMs can be used for extended periods of time (typically up to a month).  External AEMs may be used until the patient experiences cardiac symptoms/events.  Since the EKGs are recorded only during symptoms/events, there is good correlation with any underlying arrhythmia.  Conversely, if no EKG abnormality is noted, a noncardiac etiology of the patient's symptoms can be sought.

Implantable Continuous Intracardiac Ischemia Detection or Monitoring System (IIDS):

The Real-Time permanent IIDS device is designed to detect rapid ST segment changes (ST shifts) in the heart rhythm that may signify major cardiac events, such as coronary artery occlusions caused by life-threatening vulnerable plaque ruptures.  Once the ST shift is detected, the IIDS will alert the patient to seek medical care by delivering a series of vibratory, auditory, and visual warnings, using Bluetooth technology with a pager-like device continuously worn by the patient.  This implantable medical device uses a standard pacemaker intracardiac lead positioned in the right ventricular apex.  In addition to detecting acute ST changes and alerting the patient to seek medical attention, the device stores EKG traces for later analysis by the physician.  To date, there are no FDA approved devices available for use in the United States.  The AngelMed Guardian® System, from Angel Medical Systems, has been approved for use in Europe and Brazil. 

Mobile Cardiac Outpatient Telemetry (MCOT) Real-Time Remote Monitoring:

AEMs store the recorded data, which are ultimately transmitted either to a physician’s office or to a central recording station.  In contrast, MCOT provides Real-Time Remote heart monitoring and analysis.  For example, CardioNet, Inc. is a company that offers the MCOT system.  In their system, the patient wears a three-lead sensor, which constantly communicates with the MCOT monitor, a lightweight unit that can be carried in a pocket or purse.  When an arrhythmia is detected according to preset parameters, the EKG is automatically transmitted to a central CardioNet recording service station where the EKG is immediately interpreted, with results sent to the referring physician.  The referring physician can request the level and timing of response, ranging from daily reports to stat or immediate results.  This device could be used to diagnose previously unrecognized arrhythmias, document the cause of symptom complaints, and/or detail the initiation of antiarrhythmic drug therapy.  The MCOT device is not intended to monitor patients with life-threatening arrhythmias and is contraindicated for patients who have a history of ventricular tachycardia (VT) or fibrillation (VF) or thought to be a risk for VT or VF. Telemetry at Home®, part of Cardiac Telecom Corporation, markets the HEARTLinkII™ telemetry monitoring device.


Each benefit plan or contract defines which services are covered, which are excluded, and which are subject to dollar caps or other limits.  Members and their providers have the responsibility for consulting the member's benefit plan or contract to determine if there are any exclusions or other benefit limitations applicable to this service or supply.  If there is a discrepancy between a Medical Policy and a member's benefit plan or contract, the benefit plan or contract will govern.


The Coverage, Description, and Rationale information in this policy is separate for each device type as there are differences in equipment function for the same clinical conditions in addition to specific criteria applied for each device type.  The categories of equipment available are: 

  • External Holter Monitoring (HM)
  • External Real-Time or External Delayed Time Monitoring (AEM)
  • Implantable Continuous Monitoring (ICM)
  • Mobile Cardiac Outpatient Telemetry (MCOT)

External Holter Monitoring (HM):

The use of external HMs, for 24- to 48-hours ONLY, may be considered medically necessary as a diagnostic alternative to event monitoring in patients who experience frequent symptoms or events (multiple instances within 24- to 48-hours) suggestive of cardiac arrhythmias, such as any of the following;

  • palpitations;
  • chest pains, pressure, or discomfort;
  • lightheadedness, dizziness, or vertigo;
  • near-syncope/fainting or syncope/fainting.

The use of an EKG monitor patch system to evaluate heart rate measurements and rhythm analysis in asymptomatic or in patients who have experienced symptoms or events suggestive of cardiac arrhythmias, from 48-hours to up to 14-days, is considered not medically necessary.

External Real-Time Monitoring Or External Delayed Time Monitoring (AEMs) with 24-hour immediate reading availability AND external delayed-time (historical/memory) monitoring without 24-hour immediate reading availability:

The use of patient activated or auto-activated external AEMs with or without 24-hour review availability may be considered medically necessary as:

  • A diagnostic alternative to HM for patients who experience infrequent symptoms or events (less than every 48-hours) suggestive of cardiac arrhythmias, such as any of the following:
    1. palpitations;
    2. chest pains, pressure, or discomfort;
    3. lightheadedness or dizziness/vertigo;
    4. near-syncope/fainting or syncope/fainting.
  • A diagnostic method for any of the following:
    1. evaluating the cause of implanted defibrillator discharge;
    2. detecting, characterizing, and documenting symptomatic transient arrhythmias;
    3. overcoming difficulties in regulating antiarrhythmic drug dosage.

NOTE:  Any requests for the use of external AEMs greater than 30-days must include documentation of medical necessity.

Implantable Continuous Memory Loop Monitoring (ICM):

The use of patient activated or auto-activated implantable AEMs or ICMs may be considered medically necessary ONLY in the small subset of patients who;

  • Experience recurrent symptoms so infrequently that a prior trial of HM and other external AEMs has been unsuccessful; OR
  • Are incapacitated or mentally challenged and unable to activate the AEMs.

Implantable Continuous Intracardiac Ischemia Detection or Monitoring:

The use of a permanent implantable continuous intracardiac ischemia detection or monitoring system (IIDS) is considered experimental, investigational and unproven.

Mobile Cardiac Outpatient Telemetry (MCOT):

The use of MCOT as an alternative to patient activated or auto-activated AEMs is considered experimental, investigational and unproven.


Ambulatory external Holter monitors (HMs) offers an alternate method of testing for heart disease.  Traditionally, an exercise stress test has been used to diagnose or confirm heart disease.  However, an exercise stress test is not foolproof, often producing false negative or positive results.  Due to other medical conditions (such as arthritis), some patients are unable to undergo exercise stress tests.  The HM provides continuous details during a 24- to 48-hour time span.

In 2009, a newer extended EKG monitor patch system for use from 48-hours to up to 14-days was approved by the FDA.  The literature search through October 2011 reveals one clinical trial in Spain comparing a one-day HM use to a seven-day HM in 63 patients.  The authors concluded that the seven-day HM did not significantly increase the detection of nonsustained atrial tachycardia or atrial fibrillation.  They did concluded the seven-day HM improved in the detection and revealed better characterization of ventricular arrhythmic episodes, but was less useful for supraventricular events.  Therefore, not all arrhythmias are detected by extending HM beyond 48 hours.  Dagres et al. report a study published in 2010 of 215 patients using HMs for seven-days six-months after catheter ablation for atrial fibrillation.  Analysis was done on patients who had a recurrence within the first 24-, 48-, and 72- hours, etc. up to the total of seven-days.  During the complete 7-day recording, 30% had a recurrence.  They speculated that 24-hours of detection would find 59% of recurrences, a 48-hour recording would find 67% and a 72-hour HM, 80% of patients would show recurrences.  The authors concluded a HM duration of less than 4-days may miss recurrences, a 4-day recording “might offer a reasonable comprise” when compared to using a HM for 7-days.

Additional studies were also cited by the ZEUS system manufacturer, which compared standard HMs to delayed-time and/or auto-activated ambulatory event monitors (AEMs).  These studies were retro-review of patient records, randomized cross-over trials, or case-series.  In 2011, a clinical trial was started, NCT01382953, known as the “The Simple ECG Monitoring” for comparison of a sternal EKG patch system with the standard HM system.  The investigators intent is to review the “very small innovative monitor patch system that relieves the patient a cumbersome and uncomfortable recording system”.  The scientific evidence to date remains insufficient to conclude using an EKG monitor patch system beyond 48-hours up to 14-days improves health outcomes, when other AEMs are available for use beyond 48-hours.  Therefore, the coverage position of the medical policy is not medically necessary. 

Real-time AEMs reflect a trend in the medical device industry toward the miniaturization of large medical devices.  The FDA cleared the device based on design controls used in the manufacture of the device and on a comparison to standard EKGs currently marketed.  However, if a patient has a potentially serious event or a suspicion of a serious/life threatening event that requires the availability of constant 24-hour monitoring, that patient should not be managed in an outpatient setting where there is an inability to appropriately intervene immediately when the event occurs.  In that circumstance, such patients should be appropriately monitored in a hospital cardiac care unit.  The same applies to delayed-time monitoring supplemented with 24-hour technician or physician readout availability.

Delayed-time AEMs are a well-established technology that is typically used to evaluate episodes of cardiac symptoms (palpitations, dizziness, and syncope).  AEMs also monitor other cardiac conditions requiring specialized management, which, due to their infrequency, would escape detection using a standard 24- or 48-hour HM and reduce the necessity of repeated Holter monitoring.

For auto-activated AEMs, a focus review was done for the 2006 policy update.  Several studies, including an analysis of a database of 100,000 patients, compared the diagnostic yield of automatic- and patient-activated arrhythmia recordings, and reported an improved yield with auto-triggering devices.  However, one comparative study of 50 patients noted that auto-activation may result in a large number of inappropriately stored events. 

A phase II pivotal study (NCT00781118) is underway accessing the AngelMed Guardian System, a permanent implantable continuous intracardiac ischemia detection or monitoring system (IIDS).  The ALERTS (AngelMed for Early Recognition and Treatment of STEMI [ST elevation myocardial infarction]) study is a prospective, randomized multi centered pivotal trial in 100 centers and 1,020 patients with a high-risk of having a myocardial infarction or heart attack, due to acute coronary syndrome or bypass surgery.  The system is designed to detect acute ST elevation changes, to alert patients to seek medical attention, and store EKG traces for analysis.  The ALERT trial began in 2008 and is estimated for completion in May 2015.  The results of the study will be reviewed by the FDA for an investigational device exemption (IDE). 

According to the National Institutes of Health, continuous monitoring of the culprit artery is mandatory to determine the correct therapeutic intervention.  While coronary angiography reveals vessel anatomy, it is only for a brief moment; and, AEMs may be limited in the arrhythmia captured, based on the type of system used and/or inability to analyze acute ischemic events (ST-segment shifts), and patient compliance.  The authors of a current perspective and future direction review of silent myocardial ischemia, Ahmed et al., stated,   “The goal of therapeutic intervention is to reverse ongoing ischemia and to interrupt or prevent myocardial cell death”.  They deduce that to get to therapeutic goal, use of implantable monitoring is one solution. 

Currently no IIDS devices are approved by the FDA and are considered an emerging technology, the utilization of the devices are considered experimental, investigational and unproven.

Mobile cardiac outpatient telemetry (MCOT) real-time remote heart monitors.  Although these devices have the added capability of real-time cardiac monitoring and may lead to timely physician notification in the event of a serious arrhythmia, it is unknown if this form of monitoring improves health outcomes or patient management, especially when compared to established ambulatory cardiac event monitoring devices.  Patient selection criteria have not been adequately defined.  Randomized clinical trials comparing health outcomes of established monitoring techniques to the ambulatory EKG detectors with automatic-real-time event notification are required to provide evidence of clinical benefit from this form of monitoring.  A recent 2005 published study was identified that described the outcomes of a consecutive case series of 100 patients.  Patients with a variety of symptoms were included, such as palpitations (47%), dizziness (24%), or syncope (19%), in addition to efficacy of drug therapy (25%).  Clinically significant arrhythmias were detected in 51% of patients, but half of those patients were asymptomatic.  The study authors comment that the automatic detection results in an increased diagnostic yield, but there was no discussion of the MCOT service unique features, such as real-time analysis, transmission, notification of arrhythmia, and potential contraindications when used for patients with history of or at risk of serious ventricular arrhythmias.

Rothman and colleagues recently reported results comparing MCOT to standard loop recording.  This study involved 305 patients who were randomized to a LOOP recorder or MCOT and who were monitored for up to 30-days.  The unblinded study enrolled patients at 17 centers for who the investigators had a strong suspicion of an arrhythmic cause of symptoms, including those with symptoms of syncope, presyncope, or severe palpitations occurring less frequently than once per 24 hours and a nondiagnostic 24-hour HM or telemetry monitor within the prior 45 days.  Test results were read in a blinded fashion by an electrophysiologist.  Study exclusions were Class IV heart failure, myocardial infarction within the prior three months, unstable angina, history of sustained VT or VF, and complex ectopy with an ejection fraction less than 35%.

While 305 patients were randomized, results from 266 were analyzed using patients who completed at least 25-days of monitoring, 132 in the LOOP group and 134 in the MCOT group.  Of the 39 patients who did not complete the protocol, 20 did not complete (13 MCOT and seven LOOP) the study due to non-compliance (non-wearing) with the device.  Patients were predominantly female with a mean age of 56 years.  Approximately 20% had a history of heart disease, 50% hypertension, and 5% heart failure.

A diagnostic endpoint (confirmation or exclusion of arrhythmic cause of symptoms) was found in 88% of MCOT patients and 75% of LOOP patients (p = 0.008).  The difference in rates was due primarily to detection of asymptomatic (not associated with simultaneous symptoms) arrhythmias in MCOT group consisting of rapid atrial fibrillation (AF) and/or flutter (15 patients versus one patient) and VT defined as more than three beats and rate greater than 100 (14 patients versus two patients).  These were felt to be clinically significant rhythm disturbances and the likely causes of the patients’ symptoms.  The paper does not comment on the clinical impact (changes in management) of these findings in patients where the rhythm disturbance did not occur simultaneously with symptoms.  In this study, the median time to diagnosis in the total study population was seven days in the MCOT group and nine days in the LOOP group.  Of note, prior studies of the auto-triggered loop recorder have also shown similar findings that are viewed as improvements over traditional LOOP recordings that require patient activation.

A subset of only 50 patients (related to device availability) received the newer auto-trigger loop recorders.  In this subset, a diagnostic endpoint was found in 88% of the 24 MCOT patients and 46% of the auto-trigger LOOP group.  The lower yield of the auto-trigger loop recorder noted in this study is surprising; others have reported increased yield with this feature.

The auto-trigger loop recorders have become a part of the standard diagnostic approach to patients who have infrequent symptoms that are felt likely to be due to arrhythmias.  Therefore, this is the test to which newer technologies must be compared.  Currently, the literature does not provide any adequate comparative data for the auto-trigger device compared to MCOT.  Further study of MCOT is needed to replicate the Rothman study and to compare MCOT with the auto-trigger loop recorder.  MCOT is considered experimental, investigational or unproven as a diagnostic alternative in patients who experience infrequent symptoms (less frequently than 48-hours) suggestive of cardiac arrhythmias, such as palpitations, presyncope, or syncope.

MCOT continues to be studied in the evaluation of patients who have had ablation procedures, in addition to being studied as a method to measure rhythm and rate control in patients with AF.  Neither study compares MCOT with standard approaches.

There is insufficient evidence to show that outpatient cardiac telemetry or real-time event monitoring is more effective than conventional ambulatory event monitors or has a greater impact on patient management.

A literature search of MedLine database was performed through August 2008.  No studies were identified that would change the coverage position of this medical policy.


Disclaimer for coding information on Medical Policies          

Procedure and diagnosis codes on Medical Policy documents are included only as a general reference tool for each policy.  They may not be all-inclusive.           

The presence or absence of procedure, service, supply, device or diagnosis codes in a Medical Policy document has no relevance for determination of benefit coverage for members or reimbursement for providers. Only the written coverage position in a medical policy should be used for such determinations.           

Benefit coverage determinations based on written Medical Policy coverage positions must include review of the member’s benefit contract or Summary Plan Description (SPD) for defined coverage vs. non-coverage, benefit exclusions, and benefit limitations such as dollar or duration caps.

ICD-9 Codes

Refer to the ICD-9-CM manual.

ICD-10 Codes

Refer to the ICD-10-CM manual.

Procedural Codes: 33282, 33284, 93224, 93225, 93226, 93227, 93228, 93229, 93268, 93270, 93271, 93272, 93285, 93290, 93291, 93297, 93298, 93299, 99091, 0206T, 0206T, 0295T, 0296T, 0297T, 0298T, 0302T, 0303T, 0304T, 0305T, 0306T, 0307T, E0616
  1. DiMarco, J.P., and J.T. Philbrick.  Use of ambulatory electrocardiographic (Holter) monitoring. Annals of Internal Medicine (1990 July 1) 113(1):53-68.
  2. Leitch, J., Klein, G., et al. Feasibility of an implantable arrhythmia monitor. Pacing and Clinical Electrophysiology (1992 December) 15(12):2232-5.
  3. Kinlay, S., Leitch, J.W., et al.  Cardiac event recorders yield more diagnoses and are more cost-effective than 48-hour Holter monitoring in patients with palpitations.  A controlled clinical trial.  Annals of Internal Medicine (1996 January 1) 124(1 Part 1):16-20.
  4. Machado, C., Johnson, D., et al. Pacemaker patient-triggered event recording: accuracy, utility, and cost for the pacemaker follow-up clinic. Pacing and Clinical Electrophysiology (1996 November) 19(11 Part 2):1813-8.
  5. Kamalvand, K., Tan, K., et al. Ambulatory patient activated arrhythmia monitoring: comparison of a new wrist applied monitor with a conventional precordial device. Journal of Electrocardiology (1997 April) 30(2):127-31.
  6. Steinback, K., and M. Nurnberg. Present and future role of ambulatory Holter monitoring for arrhythmia risk stratification.  Pacing and Clinical Electrophysiology (1997 October) 20(10 Part 2):2587-93.
  7. Porterfield, J.G., Porterfield, L.M., et al. Daily variations in the occurrence of symptomatic supraventricular tachycardia as determined by ambulatory event monitoring. American Journal of Cardiology (1997 October 1) 80(7):889-91.
  8. Chu, A.C. Improved remote event marker for use in ambulatory monitoring. Medical and Biological Engineering and Computing (1998 March) 36(2):238-40.
  9. Zimetbaum, P.J., Kim, K.Y., et al. Diagnostic yield and optimal duration of continuous-loop event monitoring for the diagnosis of palpitations. A cost-effectiveness analysis. Annals of Internal Medicine. (1998 June 1) 128(11):890-5.
  10. Zimetbaum, P.J., and M.E. Josephson. The evolving role of ambulatory arrhythmia monitoring in general clinical practice. Annals of Internal Medicine.  (1999 May 18) 130(10):848-56.
  11. Balmelli, N., Naegeli, B., et al. Diagnostic yield of automatic and patient-triggered ambulatory cardiac event recording in the evaluation of patients with palpitations, dizziness, or syncope. Clinical Cardiology (2003 April) 26(4):176-6.
  12. Vaisanen, O., Makijarvi, M., et al. Prehospital ECG transmission: comparison of advanced mobile phone and facsimile devices in an urban Emergency Medical Service System. Resuscitation (2003 May) 57(2):179-85.
  13. Kowey, P.R., and D.Z. Kocovic. Ambulatory electrocardiographic recording. Circulation (2003 August 5) Reprint (108):1-3.
  14. Louis, A.A., Turner, T., et al. A systematic review of telemonitoring for the management of heart failure. European Journal of Heart Failure (2003 October) 5(5):583-90.
  15. Ermis, C., Zhu, Z.X., et al. Comparison of automatic and patient-activated arrhythmia recordings by implantable loop recorders in the evaluation of syncope.  American Journal of Cardiology (2003 October 1) 92(7):815-9.
  16. Zarakovitis, K., Angelidis, P., et al. Ambulatory monitoring for chronic cardiac and pulmonary patients. Studies in Health Technology and Informatics (2004) 103:362-7.
  17. Zhou, H., Hou, K.M., et al. Remote continuous cardiac arrhythmias detection and monitoring. Studies in Health Technology and Informatics (2004) 105:112-20.
  18. Ng, E., Stafford, P.J., et al. Arrhythmia detection by patient and auto-activation in implantable loop recorders.  Journal of Interventional Cardiac Electrophysiology (2004 April) 10(2):147-52.
  19. Jabaudon, D., Sztajzel, J., et al.  Usefulness of ambulatory 7-day  ECG monitoring for the detection of atrial fibrillation and flutter after acute stroke and transient ischemic attack.  Stroke (2004 July) 35(7):1647-51.
  20. Martinez, T., and J. Sztajzel.  Utility of event loop recorders for the management of arrhythmias in young ambulatory patients.  International Journal of Cardiology (2004 December) 97(3):495-8.
  21. Joshi, A.K., Kowey, P.R., et al. First experience with a Mobile Cardiac Outpatient Telemetry (MCOT) system for the diagnosis and management of cardiac arrhythmia.  American Journal of Cardiology (2005 April 1) 95(7):878-81.
  22. Reiffel, J.A., Schwarzberg, R., et al. Comparison of auto triggered memory loop recorders versus standard loop records versus 24-hour Holter monitors for arrhythmia detection. American Journal of Cardiology (2005 May 1) 95(9):1055-9.
  23. Ambulatory Event Monitors. Chicago, Illinois: Blue Cross Blue Shield Association Medical Policy Reference Manual (2005 October) Medicine: 2.02.08.
  24. Vasamreddy, C.R., Dalal, D., et al.  Symptomatic and asymptomatic atrial fibrillation in patients undergoing radiofrequency catheter ablation.  Journal of Cardiovascular Electrophysiology (2006 February) 17:134-9.
  25. Hoefman, E., van Weert, H.C., et al.  Optimal duration of event recording for diagnosis of arrhythmias in patients with palpitations and light-headedness in the general practice.  Family Practice (2007 February) 24(1):11-3.
  26. Prystowsky, E.N.  Assessment of rhythm and rate control in patients with atrial fibrillation.  Journal of Cardiovascular Electrophysiology (2006 September) Supplement 2:S7-S10.
  27. Naccarelli, G.V. Ambulatory electrocardiographic monitoring: has mobile cardiac outpatient telemetry changed the playing field?  Journal of Cardiovascular Electrophysiology (2007 March) 18:1-2.
  28. Rothman, S.A., Laughlin, J.C., et al.  The diagnosis of cardiac arrhythmias: a prospective multi-center randomized study comparing mobile cardiac outpatient telemetry versus standard loop event monitoring.  Journal of Cardiovascular Electrophysiology (2007 March) 18:1-7.
  29. Ambulatory Event Monitors and Mobile Cardiac Outpatient Telemetry.  Chicago, Illinois: Blue Cross Blue Shield Association Medical Policy Reference Manual (2007 September) Medicine: 2.02.08.
  30. Olson, J.A., Fouts, A.M., et al.  Utility of mobile cardiac outpatient telemetry for the diagnosis of palpitations, presyncope, syncope, and the assessment of therapy efficacy.  Journal of Cardiovascular Electrophysiology (2007 July) 18:1-5.
  31. Ahmed, A.H., Shankar, K.J., et al.  Silent myocardial ischemia: current perspectives and future directions.  Experimental and Clinical Cardiology (2007 Winter) 12(4):189-96.
  32. Hopenfeld, B., John, M.S., et al.  The Guardian: an implantable system for chronic ambulatory monitoring of acute myocardial infarction.  Journal of Electrocardiology (2009 November-December) 42(6):481-6.  Epub (2009 July 24).
  33. Dagres, N., Kottkamp, H., et al.  Influence of the duration of Holter monitoring on the detection of arrhythmia recurrences after catheter ablation of atrial fibrillation: implications for patient follow-up.  International Journal of Cardiology (2010 March 18) 139(3):305-6.
  34. Fischell, T.A., Fischell, D.R., et al.  Initial clinical results using intracardiac electrogram monitoring to detect patients during coronary plaque rupture and ischemia.  Journal of the American College of Cardiology (2010 September 28) 56:1089-98.
  35. Scirica, B.M., Braunwald, E., et al.  Relationship between nonsustained ventricular tachycardia after non-ST-elevation acute coronary syndrome and sudden cardiac death: observations from the metabolic efficiency with ranolazine for less ischemia in non-ST-elevation acute coronary syndrome-thrombolysis in myocardial infarction 36 (MERLIN-TIMI 36) randomized controlled trial.  Circulation (2010 August 3) 122(5):455-62.
  36. Pastor-Parez, F.J., Manzano-Fernandez, S., et al.  Comparison of detection of arrhythmias in patients with chronic heart failure secondary to non-ischemic versus ischemic cardiomyopathy by 1- versus 7-day Holter monitoring.  American Journal of Cardiology (2010 September 1) 106(5):677-81.
  37. – The Simple ECG Monitoring Trial (Comparison of a Novel Recording System With a Standard Holter Monitor) (NCT01382953) (2011 June 24).  U.S. National Institutes of Health – Clinical Trials.  Available at (accessed on 2011 October 14).
  38. Edgerton, J.R., Mahoney, C., et al.  Long-term monitoring after surgical ablation for atrial fibrillation: how much is enough?  Journal of Thoracic and Cardiovascular Surgery (2011 July) 142(1):162-5.
  39. Papavasileiou, L.P., Forleo, G.B., et al.  Early detection of chronic myocardial ischemia in a patient implanted with an ICD capable of intracardiac electrogram monitoring.  Journal of Invasive Cardiology (2011 December) 23(12):532-3.
  40. AngelMed Guardian – Product information.  Shresbury, New Jersey: Angel Medical System.  (2012).
  41. – AngelMed for Early Recognition and Treatment of STEMI (ALERTS). (NCT00781118) (2012 May 23).  U.S. National Institutes of Health – Clinical Trials.  Available at (accessed – 2012 June 4).
September 2013  Policy formatting and language revised.  Added criteria for Holter monitors to the policy statement.  Title changed from "Ambulatory Event Monitors and Moble Cardiac Outpatient Telemetry" to "Ambulatory Cardiac Event Monitors (AEMs or CEMs) including Mobile Cardiac Outpatient Telemetry (MCOT)". 
®Registered marks of the Blue Cross and Blue Shield Association, an association of independent Blue Cross and Blue Shield Plans. ®LIVE SMART. LIVE HEALTHY. is a registered mark of BCBSMT, an independent licensee of the Blue Cross and Blue Shield Association, serving the residents and businesses of Montana.
CPT codes, descriptions and material only are copyrighted by the American Medical Association. All Rights Reserved. No fee schedules, basic units, relative values or related listings are included in CPT. The AMA assumes no liability for the data contained herein. Applicable FARS/DFARS Restrictions Apply to Government Use. CPT only © American Medical Association.
Ambulatory Cardiac Event Monitors (AEMs or CEMs) including Mobile Cardiac Outpatient Telemetry (MCOT)