Inappropriate discharge by an implantable cardioverter defibrillator: recognition of myopotential sensing using telemetered intracardiac electrograms

Area of Science:

• Cardiology and Biomedical Engineering
• Electrophysiology and Device Therapy

Background:

• Inappropriate therapy delivery from implantable anti-tachyarrhythmia devices is a significant clinical challenge.
• Older device generations lacked adequate data storage and intracardiac electrogram (ICG) analysis capabilities, hindering diagnosis of shock triggers.
• Absence of premonitory symptoms is an unreliable indicator for assessing defibrillator shock appropriateness.

Observation:

• A case report details inappropriate implantable cardioverter defibrillator (ICD) discharge.
• The specific cause identified was myopotential sensing, where muscle electrical activity was misinterpreted as a cardiac arrhythmia.
• Diagnosis was challenging due to limitations in event verification with earlier device models.

Findings:

• Newer ICDs with enhanced data storage and the ability to review telemetered intracardiac electrograms significantly improve diagnostic capabilities.
• Analysis of intracardiac electrograms was crucial in identifying myopotential sensing as the cause of inappropriate shocks.
• This facilitated accurate diagnosis of abnormal device behavior.

Implications:

• Improved data logging and electrogram review in modern ICDs enhance the ability to diagnose and manage inappropriate shocks.
• Understanding myopotential sensing as a cause of inappropriate ICD therapy is critical for device programming and patient management.
• This advancement supports more precise and effective anti-tachyarrhythmia device therapy.