When is a Bardy continuous ambulatory cardiac monitor indicated?

When to Order a Bardy Cam (Implantable Cardiac Monitor)

Order a Bardy Cam (implantable cardiac monitor/ICM) for patients with infrequent symptoms occurring more than 30 days apart—such as syncope, presyncope, or palpitations—when initial noninvasive evaluation (ECG, Holter, external monitors) is nondiagnostic. 1

Primary Indications

Infrequent Unexplained Symptoms

• Recurrent syncope or presyncope that occurs less than monthly after a nondiagnostic initial workup, with or without structural heart disease 1
• Palpitations occurring more than 30 days apart when shorter-term monitoring has failed to capture events 2
• Symptoms too infrequent, brief, or subtle to be documented with patient-activated external monitors 1

Suspected Bradycardia or Conduction Disorders

• Infrequent symptoms potentially related to bradycardia (sinus node dysfunction, high-grade AV block) when external monitoring is nondiagnostic 1
• Suspected neurocardiogenic syncope with predominant cardioinhibitory component requiring long-term rhythm correlation 1

High-Risk Patients Requiring Real-Time Surveillance

• Patients whose rhythm requires continuous monitoring but symptoms are too sporadic for external devices 1
• Evaluation for serious tachyarrhythmias (including ventricular arrhythmias) and bradyarrhythmias in patients with life-threatening symptoms 1

Key Advantages Over Other Monitoring Strategies

Extended Monitoring Duration

• Battery life of 2-3 years allows capture of very infrequent events that would be missed by shorter-term monitors 1, 2
• Continuous rhythm monitoring with automatic detection of significant arrhythmias plus patient/family activation capability 1

Superior Diagnostic Yield

• 25% added diagnostic yield compared to external ambulatory monitors in patients with nondiagnostic initial workup 1
• Randomized trials demonstrate ICM is more effective than conventional testing (24-hour Holter, ECG, treadmill) in obtaining clinical diagnosis of syncope 1
• Many diagnosed conditions are bradycardia-mediated (high-grade AV block, sinus node dysfunction) successfully treated with permanent pacing 1

Remote Monitoring Capability

• Automatic transmission of significant arrhythmias to monitoring station without patient activation 1
• Allows for transtelephonic transmission and remote monitoring by trained technicians 1

Algorithmic Approach to Device Selection

Match Monitoring Duration to Symptom Frequency

Daily symptoms (≥1 episode per day):

• Use 24-48 hour Holter monitor 1, 2, 3

Weekly to monthly symptoms (every 2-6 weeks):

• Use external loop recorders, adhesive patch monitors (2-14 days), or mobile cardiac outpatient telemetry (up to 30 days) 1, 2, 3

Infrequent symptoms (>30 days between episodes):

• Use implantable cardiac monitor 1, 2

After Nondiagnostic Initial Workup

• If 24-48 hour Holter and external event monitors fail to capture events, escalate to ICM rather than repeating short-term monitoring 1
• ICM is particularly valuable when previous conventional testing (ECG, Holter, tilt table, electrophysiology study) has been unrevealing 1

Common Pitfalls and How to Avoid Them

Selecting Insufficient Monitoring Duration

• Most common error: Ordering 24-48 hour Holter for patients with monthly symptoms results in low diagnostic yield and wasted resources 2, 3
• Solution: Match device duration to symptom frequency—if symptoms occur less than monthly, proceed directly to ICM 2, 3

Relying on Patient Activation Alone

• Patient inability to activate device during sudden syncope reduces diagnostic yield 2
• Solution: ICM offers automatic detection algorithms that capture events even without patient activation 1

Failure to Correlate Symptoms with Rhythm

• Asymptomatic arrhythmias detected on monitoring should not guide diagnosis without symptom correlation 4
• Solution: Emphasize importance of patient/family symptom diaries and event activation to establish symptom-rhythm correlation 1, 2, 4

Premature Device Selection

• Ordering ICM before completing basic noninvasive evaluation wastes resources 1
• Solution: ICM is indicated only after initial workup (ECG, echocardiography, shorter-term monitoring) is nondiagnostic 1

Clinical Context: When ICM Changes Management

Bradycardia Detection Leading to Pacing

• Many ICM-diagnosed conditions (high-grade AV block, severe sinus node dysfunction, neurocardiogenic syncope with cardioinhibitory component) are successfully treated with permanent pacemaker implantation 1

Excluding Arrhythmic Causes

• ICM can exclude arrhythmia as cause when symptoms occur with normal sinus rhythm, avoiding unnecessary interventions 4

High-Risk Populations

• Post-MI patients with LVEF <40% had NSVT detected in 13%, sustained VT in 3%, and VF in 3% on ICM monitoring 1

Specific Device Characteristics

Implantation and Use

• Subcutaneously implanted with minor invasive procedure under local anesthesia 1
• Leadless design allows accurate self-application and is water-resistant, improving compliance over external monitors 1
• Provides only 1-lead recording (unlike multi-lead Holter monitors) 1

Infrastructure Requirements

• Appropriate infrastructure must be present to facilitate timely notification of patient and provider when dangerous abnormalities are identified 1
• Remote monitoring with 24-hour attended central monitoring station for automatic transmissions 1