Pacemaker/implantable cardioverter-defibrillator interaction.

Area of Science:

• Cardiology
• Biomedical Engineering

Background:

• A dual-chamber implantable cardioverter-defibrillator (ICD) system was implanted in an 83-year-old male with ischemic cardiomyopathy for battery depletion and symptomatic bradycardia.
• Initial device parameters and lead function were assessed, showing no immediate signs of cross-talk or sensing issues.

Observation:

• During a defibrillation threshold (DFT) test, induced ventricular fibrillation (VF) was not detected by the ICD.
• The device printout revealed atrial/ventricular lead cross-talk, triggered by the shock, which activated noise-reduction algorithms and prevented VF detection.
• Ventricular sensing of atrial pacing artifacts also interfered with automatic gain control, perpetuating AV pacing and hindering VF detection.

Findings:

• The interaction between the pacemaker and ICD components led to a failure in detecting a life-threatening ventricular fibrillation (VF) arrhythmia.
• This interaction was attributed to the shock artifact causing noise detection and atrial pacing artifacts interfering with sensing and gain control.

Implications:

• Pacemaker-ICD interactions can compromise device function and patient safety in dual-chamber systems.
• Programming strategies, including shorter AV delays, increased sensitivity, and post-shock pacing pauses, are crucial for preventing such interactions.
• This case highlights the importance of thorough device testing and tailored programming to ensure reliable performance of complex cardiac implantable electronic devices.