The "Pain wave": P‑wave oversensing in subcutaneous ICD

Area of Science:

• Cardiology
• Biomedical Engineering

Background:

• Subcutaneous implantable defibrillators (S-ICDs) offer an alternative to transvenous devices for sudden cardiac arrest prevention.
• Idiopathic ventricular fibrillation necessitates device implantation for arrhythmia management.

Observation:

• A 46-year-old male patient developed inappropriate shocks from his S-ICD.
• The event was attributed to P- and T-wave oversensing, leading to triple counting.

Findings:

• Despite advanced discrimination algorithms like INSIGHT(TM), oversensing remains a challenge.
• The incidence of oversensing-related shocks can be reduced but not entirely eliminated.

Implications:

• Regular and thorough evaluation of sensing vectors during various patient activities is essential.
• Optimizing S-ICD sensing performance requires ongoing vigilance and patient monitoring.
• This case highlights the need for continuous assessment of S-ICD function post-implantation.