What should be assessed during a routine pacemaker check‑up?

Pacemaker Check-Up Assessment

During a routine pacemaker check-up, you must systematically assess device function through both non-magnet and magnet-applied ECG evaluation, interrogate stored diagnostic data, verify lead integrity and battery status, and optimize programming based on current thresholds and patient needs. 1

Core Assessment Components

Non-Magnet ECG Evaluation (Free-Running Assessment)

• Determine pacing dependency: Observe whether the patient displays intrinsic rhythm or is being intermittently or continuously paced at programmed settings 1, 2
• Characterize underlying atrial mechanism: Identify if the patient is in sinus rhythm, atrial fibrillation, atrial tachycardia, or other atrial arrhythmias 1, 2
• Verify appropriate sensing: Confirm that intrinsic cardiac events (both atrial and ventricular for dual-chamber devices) appropriately inhibit pacing output, demonstrating normal sensing function 1, 2, 3
• Obtain 6-9 second ECG strips: This duration is sufficient to demonstrate all necessary diagnostic points 1, 3

Magnet-Applied ECG Evaluation

• Verify effective capture: Apply a magnet to convert the device to asynchronous pacing mode (VOO for single-chamber, DOO for dual-chamber) and confirm that each pacing spike produces the appropriate cardiac response—P waves for atrial pacing and QRS complexes for ventricular pacing 1, 2, 3
• Assess magnet rate: Determine the current magnet rate and compare it with previous values to detect changes that may indicate battery depletion or approaching elective replacement indicators 1, 2
• Evaluate pulse width changes: If the device uses pulse width as an elective replacement indicator, assess and compare with previous values 1
• Verify AV interval changes: For dual-chamber pacemakers where magnet application alters AV interval, demonstrate and verify this programmed feature 1, 3
• Analyze automated threshold tests: If the device has Threshold Margin Test or similar features programmed "on," review and analyze these results 1, 3

Device Interrogation and Diagnostic Data

Technical Parameters

• Battery status and voltage: Check current battery voltage and compare against manufacturer specifications for elective replacement indicators 1, 4
• Lead impedance measurements: Regular impedance monitoring allows early detection of lead insulation breaks, fractures, or dislodgement 1, 5
• Pacing thresholds: Measure current atrial and ventricular pacing thresholds to optimize output programming and maximize battery longevity 1, 4
• Sensing amplitudes: Verify adequate P-wave and R-wave amplitudes to ensure reliable sensing 1

Stored Diagnostic Information

• Review stored intracardiac electrograms: Analyze EGMs to identify oversensing, undersensing, or arrhythmias that may have occurred between visits 5, 6
• Assess pacing percentages: Determine the percentage of atrial and ventricular pacing to understand pacing burden and guide programming adjustments 6
• Evaluate arrhythmia logs: Review device-detected atrial and ventricular arrhythmias, including mode switches and high ventricular rate episodes 5, 6
• Check for device alerts: Review any automated alerts regarding lead issues, battery status, or other technical problems 5

Programming Optimization

• Adjust output settings: Program pacing outputs to provide adequate safety margin (typically 2:1) above measured thresholds while maximizing battery longevity 1
• Optimize sensing parameters: Adjust sensitivity settings to ensure reliable sensing while avoiding oversensing of non-cardiac signals 1
• Verify pacing mode appropriateness: Confirm the programmed mode remains suitable for the patient's current clinical status and conduction system 1
• Review rate-adaptive settings: For rate-responsive devices, assess whether sensor-driven rate changes are appropriate for the patient's activity level 1

Clinical Evaluation

• Assess overall clinical condition: Evaluate for symptoms potentially related to pacing, including pacemaker syndrome, heart failure progression, or new arrhythmias 1
• Screen for complications: Look for pocket-related issues (infection, erosion, hematoma), lead-related problems, or symptoms suggesting device malfunction 1
• Review medication changes: Document any new antiarrhythmic drugs or other medications that might affect pacing thresholds or conduction 4

Critical Pitfalls to Avoid

• Large pacing artifacts obscuring capture: Pacing spikes may obscure or mimic QRS complexes, making capture assessment difficult—use multiple ECG leads to optimize visualization 2
• Assuming magnet function without verification: Some pacemaker models allow magnet response to be programmed off; always verify magnet response before relying on it for assessment 1
• Overlooking stored diagnostic data: Remote monitoring and device interrogation detect clinically actionable events 66% more frequently than basic transtelephonic monitoring alone 7
• Premature or delayed generator replacement: Proper evaluation of battery status prevents both unnecessary early replacement and dangerous delays past true end-of-life 1, 4
• Ignoring lead impedance trends: Gradual impedance changes may indicate developing lead problems before complete failure occurs 5

Follow-Up Frequency

• Newly implanted devices: Perform in-person evaluations twice within the first 6 months after implantation 4
• Established single-chamber pacemakers: Schedule annual in-person evaluations 4
• Established dual-chamber pacemakers: Conduct evaluations every 6 months 4
• Battery Watch activation: Increase monitoring frequency to every 3 months when battery indicators activate 4
• Unscheduled evaluations: Perform immediate assessment if patients experience symptoms suggesting rhythm changes or device malfunction 1, 4