INTRODUCTION

Reliable EKG monitoring is the backbone of arrhythmia diagnosis and management

Accurate diagnosis (or exclusion) of arrhythmias responsible for symptoms is critical for effective patient care

Outpatient EKG monitoring has the potential to shape clinical practice

Evolution of Outpatient Cardiac Ambulatory Monitoring

Holter Monitor

Event Monitor:

Non-Looping Memory

Event Monitor:Looping Memory

AFAuto-Trigger

Monitor

OutpatientTelemetry:

Patient Homebound

MobileCardiac

OutpatientTelemetry

(MCOT)

Implantable Loop

Recorder

THE EVOLUTION OF OUTPATIENT AMBULATORY CARDIAC MONITORING

HOLTER MONITOR

Technology

– 5 electrodes

– 2-3 leads

– Derived 12 lead available

– Digital or analog recording

– Digital transmission to analyzer

– Requires removal of Holter monitor to scan recording

Uses:

– Patients experiencing daily symptoms

– Precise quantification of arrhythmiasPositives:

– 24-48 hours full disclosure available

– Heart rate and AF burden graphs

– Arrhythmia counts (ex., 10 PVCs per hour)

HOLTER MONITOR

Negatives:– 24 -48 hour-short duration– May be days after test completion before

MD has results– Artifact may not be discovered until test

analyzedDiagnostic yields:

– Yields low for intermittent symptoms or syncope: <5%1 to 13%2

1. Gibson TC, Heitzma MR. Diagnostic efficacy of 24-hour electrocardiographic monitoring for syncope. AM J Cardiol 1984;53:1013-1017.

2. Zeldis SM, Levine BJ, Michelson EL, Morganroth J. Cardiovascular complaints. Correlation with cardiac arrhythmias on 24-hour electrocardiographic monitoring. Chest 1980;78:456-461.

HOLTER MONITOR

Technology:– Electrodes not attached to skin, located on

monitor– Chest plate, “wrist watch” monitors– Single lead transmission– Patient feels symptoms, places monitor and

pushes record button– Recorded event must be transmitted via phone.

Patient required to dial number and play back event then erase memory

– May have 1-6 events, approximately 6 minutes of memory

EVENT MONITOR: NON-LOOPING MEMORY

Uses:– Infrequent symptoms

• Patients with allergy to electrode patches• Patients unable to manage electrode

patchesPositives:

– Patient is not attached to electrodes

EVENT MONITOR: NON-LOOPING MEMORY

EVENT MONITOR: NON-LOOPING MEMORY

Negatives:– Delay in documenting symptoms: Patient senses

symptoms and then places monitor and pushes button on monitor to record symptoms

– Requires patient intervention to transmit: Patient needs to go to telephone, dial number and transmit ECG data

– No trending data (heart rate, AF)– Compliance: Patient must remember to have

monitor at all times, patients forget how to use technology due to infrequent use, etc.

– Single lead ECG rhythm strip

Technology:– Patient must press record button to capture symptomatic event

– Continuous loop of pre-memory that is programmable. Patient pushes button for symptoms and pre-memory is captured with post symptom ECG. Usually 45 seconds pre and 15 seconds post symptoms.

– 2 electrodes attached to skin

– Routinely transmits 1 lead but may transmit 2 leads

– Recorded event must be transmitted via phone. Patient required to dial number and play back event then erase memory

– May have 1-6 events, approximately 6-10 minutes of memory

EVENT MONITOR: LOOPING MEMORY

Uses:

– Infrequent symptoms

– Drug managementPositives:

– Looping memory

EVENT MONITOR: LOOPING MEMORY

Negatives:– Requires patient to have symptoms– Requires patient intervention to transmit– Diagnostic yield 6% - 68% (syncope, palpitations)– No trend data (heart rate or AF burden)– Electrode irritation– Non-compliance 23%-44% 1,2: failure to activate,

human error, intimidated by technology, inconvenient, difficulty with electrodes

1. Sivakumaran S, Krahn AD, Klein GJ, Finan J, Yee R, Renner S, Skanes AC. A prospective randomized comparison of loop recorders versus Holter monitors in patients with syncope or presyncope. AM J Med 2003;115:1-5.

2. Linzer M, Pritchett EL, Pontinen M, et al. Incremental diagnostic yield of loop electrocardiographic recorders in unexplained syncope. AM J of Cardiol 1990;66:214-219.

EVENT MONITOR: LOOPING MEMORY

Diagnostic yields:– Palpitations/Symptoms: Yields of 39%1-68%2,3

reported – Syncope/presyncope: Yields of 6%-25%3,4,5

1. Fechter P. Advantage of ECG self-recording by the patient. Schw Medi Wochenschr J suisse Med 1991;121:1488-1492.

2. Kinlay S, Leitch JW, Neil A, 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. Ann Intern Med 1996;124:16-20.

3. Fogel RI, Evans JJ, Prystowsky EN: Utility and cost of event recorders in the diagnosis of palpitations, presyncope, and syncope.

4. Linzer M, Prichett EL, Pontinem M, et al. Incremental diagnostic yield of loop electrocardiographic recorders in unexplained syncope. Am J Cardiol 1997;79:207-208.

5. Ximetbaum P, Kim KY, Ho KKL, et al. Utility of patient-activated cardiac event recorders in general clinical practice. Am J Cardiol. 1997;79:371-372

EVENT MONITOR: LOOPING MEMORY

AF AUTO-TRIGGER EVENT MONITORTechnology:

– Algorithm located in monitor:• Irregular irregularity • High and low heart rates• May have “pause”

– Programmable memory, 10-20 minutes in duration– Memory partitioned for auto-trigger and patient triggered

events– Recorded events must be transmitted via telephone Patient

required to dial number and play back events then erase memory

– Patient wears 2-5 electrodes, transmits 1-2 leadsUses:

– Patients with symptoms suggestive of AF, a history of AF, or being treated for AF

– Infrequent symptoms

Positives:– Algorithm captures arrhythmias on asymptomatic

patients Negatives:

– Limited monitor memory-events may not be captured– False negatives due to limited monitor memory– Artifact causes inappropriate algorithm triggering– No trend data (heart rate or AF burden)– Recorded events must be transmitted via phone.

Patient required to dial number and play back events then erase memory

– Electrode irritation– Compliance with monitoring

AF AUTO-TRIGGER EVENT MONITOR

Diagnostic yields:– Retrospective database analysis

• 600 patients reviewed for diagnostic events• 36% yield1

1. Reiffel, JA, Schwartzberg R, Murray M. Comparison of autotriggered memory loop recorders versus standard loop recorders versus 24-hour Holter monitors for arrhythmia detection. Am J Cardiol. 2005;95:1055-1059.

AF AUTO-TRIGGER EVENT MONITOR

IMPLANTABLE LOOP RECORDER

Technology:– Continuous monitoring via algorithm embedded in

recorder• High and low rates• Pauses

– Automatic and patient activation of events– Battery life 14-24 months depending on time on shelf

and patient variability of use– 21-42 minutes of memory– Events downloaded via pacemaker programmer– Patient activated mode, looping memory (5-6 events)– No remote transmission capabilities– Minimally invasive procedure to implant

Uses– Very infrequent symptoms with suspected arrhythmia– Syncope when non invasive testing is negative

Positives:– Algorithm recognizes arrhythmia without patient

needing to intervene– Extending monitoring period– Improved ability to correlate infrequent symptoms with

ECG rhythm

IMPLANTABLE LOOP RECORDER

Negatives– Invasive procedure– Over/undersensing causing false positives – No ability to transmit remotely– Limited memory

Diagnostic yields:– ECG correlation with symptoms 45-88%1,2,3

1. Krahn AD, Klein GJ, Yee R. Et al. Randomized Assessment of Syncope Trial: Conventional diagnostic testing versus a prolonged monitoring strategy. Circulation 2001; 104:46-51.

2. Krahn AD, Klein GJ, Skanes AC, Yee R. Insertable loop recorder use for detection of intermittent arrhythmias. Pace 2004;27:657-664.

3. Assar M, Krahn A, Klein G, Yee R, Skanes A. Optimal duration of monitoring in patients with unexplained syncope. AM J Cardiol 2003;92:1231-3.

IMPLANTABLE LOOP RECORDER

Technology:– Algorithm embedded in computer tower set in home– Computer tower connected to phone line– Patient module worn on belt and connected to patient

by electrodes– Patient module transmits ECG signal to computer

tower– Automatic and patient activated events

– ECG events transmitted automatically via phone line

OUTPATIENT TELEMETRY-In Home Only

Uses:– Post CABG atrial fibrillation– Infrequent symptoms– Drug management

Positives:– Beat by beat analysis– 24 hours of stored ECG data– Heart rate trending– Physician daily reporting

OUTPATIENT TELEMETRY-In Home Only

Negatives:– Patient home bound– No cellular capabilities, all ECG events

transmitted via land line connected to computer tower in home

– Unable to monitor patient when patient separated from computer tower

OUTPATIENT TELEMETRY-In Home Only

MOBILE CARDIAC OUTPATIENT TELEMETRY (MCOT)

Technology:– 3 electrode Sensor worn by patient– Sensor transmits ECG to Monitor– Beat by beat analysis via embedded algorithm– Touch screen for patient to report symptoms– Patient and algorithm triggered events– Monitor has cellular capability and 2 way text

communication with patient– Base connected to phone line placed in patient’s home – 96 hours of ECG memory capacity-ability to access ECG

data from memory– Trend reporting for heart rate and AF burden

Uses:– Infrequent symptoms suggestive of arrhythmia

(palpitations, syncope, presyncope, etc)– Patient who require monitoring for known,

non-life threatening arrhythmias (AF, PSVT, etc)

– Post cardiac surgery– Post ablation– Drug management

MOBILE CARDIAC OUTPATIENT TELEMETRY (MCOT)

Positives:– Beat by beat analysis, not patient dependent to capture

event– Symptom correlation via touch screen on Monitor– Heart rate and AF trending– High compliance due to daily reporting– Ability to contact patient– 96 hours of retrievable memory– Patient able to be mobile

Negatives:– Electrode irritation

MOBILE CARDIAC OUTPATIENT TELEMETRY (MCOT)

First Experience with a Mobile Outpatient Telemetry (MCOT) System for the Diagnosis and Management of Cardiac Arrhythmia, Joshi A,

Kowey P, etal, AM J Cardiol April 2005; Vol 95,Issue 7

100 Patients – 16 of 30 patients with prior negative Holter or

event monitoring diagnosed with MCOT– Clinically significant arrhythmia found in 51 of

100 patients– 13 of 17 patients diagnosed with atrial

fibrillation had no symptoms

First 100 Patients on Service

Outcomes 14 Required drug therapy 5 Pacemaker implants 4 Ablations 3 Changed drug therapy 2 ICD implant 2 Stopped Coumadin 2 Alternate diagnosis 1 Stopped therapy 1 Pacemaker replacement

30 Patients with prior Holter or Event

Outcomes 7 Required drug therapy 3 Pacemaker implants 2 2nd Deg AV Block 1 ICD implant 1 Ablation 1 NSVT 1 Second accessory

pathway

Outcomes of “First Experience” Study

Other MCOT Research

Symptomatic and Asymptomatic Atrial Fibrillation in Patients Undergoing Radiofrequency Catheter Ablation, Vasamreddy DD, Calkins H, Journal of CV Electrophysiology, Feb 2006; Vol 17:2– 82% of atrial fibrillation events were asymptomatic

– 20% of patients considered AF-free based on symptoms reporting actually had recurrent AF

– Patients in AF frequently triggered symptoms when they were in NSR Assessment of Rhythm and Rate Controls in Patients with Atrial

Fibrillation, Prystowsky, EN, Journal of CV Electrophysiology, Sept 2006; Vol 17:9– Symptoms do not always correlate with AF, most patients have

asymptomatic AF

– Assumption: optimal physiological response during sinus rhythm can be duplicated by similar rate during AF

Other MCOT Research

Incidence of Asymptomatic Atrial Fibrillation Recurrence Post Pulmonary Vein Isolation Using a Novel Continuous Event Monitoring System, Tarakji KG, Natale A, Heart Rhythm 2005 Scientific Sessions– Continuous event monitoring (MCOT) seems to help facilitating the

decision to stop anticoagulation treatments. Initial Experience with a Novel Cardiac Outpatient Telemetry

System for Pediatric Patients with Suspected Arrhythmia, Saarel EV, Sierba R, Heart Rhythm 2005 Scientific Sessions– Looked at yields for patients with palpitations, syncope and presyncope

using MCOT versus event monitoring

– “MCOT is safe and useful for evaluation of children and adolescents with suspected arrhythmia providing a diagnosis is 64% of subjects.”

(Recently completed) Rothman, SA, Laughlin JC, Seltzer J, Walia JS, Baman, RI, Siouffi SY, Sangrigoli RM, Kowey PR. “The Diagnosis of Cardiac Arrhythmias: A prospective Multi-Center Randomized Study Comparing Mobile Cardiac Outpatient Telemetry versus Standard Loop Event Monitoring”

Abstract: American Heart Association Scientific Sessions 2006. Oral presentation: Nov. 14 11:45-12 PM

MOBILE CARDIAC OUTPATIENT TELEMETRY (MCOT) CLINICAL TRIAL

Patient History– 71 year old woman with history of hypertension– Long history of feeling “shaky” with associated

extreme fatigue– Multiple Holter and event monitoring, over 10

years, detected no arrhythmic events– Patient treated with anti-anxiety medications

10/29 Cardiologist enrolls patient in MCOT baseline indicated Normal Sinus Rhythm

11/2 MCOT triggered automatically, transmitting a wide QRS complex tachycardia at a rate of 210 BPM - no symptoms reported

Physician notified, patient contacted and directed to ER Cardiologist terminated tachycardia with carotid sinus

pressure EP study induced focal right atrial tachycardia and

patient underwent with successful mapping and ablation

MOBILE CARDIAC OUTPATIENT TELEMETRY (MCOT) CASE STUDY #1

CardioNet Daily Report-No AF Burden

CardioNet Daily Report-With AF Burden Graph

CardioNet Urgent Report

CardioNet Urgent Report

CardioNet Urgent Report

CardioNet End of Service Summary Report

CardioNet Reporting Options

Web reporting only Editing reports on the web

– Interpretation by Physician

Physician Notification Criteria changes Additional ECG data available

OTHER USES OF MCOT

Quantify arrhythmia on therapyIdentify arrhythmias without symptoms

(especially AF)Safe drug administration / dose titrationExclude arrhythmias with vague

symptoms

CONCLUSION

New technologies are now available for outpatient EKG monitoring

Proof of utility must come from well-conceived clinical trials

MCOT fills a void in patient careWe can expect extension of this

technology to other aspects of ambulatory patient monitoring

QUESTIONS?