The subcutaneous implantable cardioverter-defibrillators (s-ICDs) proven efficacy is challenged by the occurrence of inappropriate shocks, mostly due to signal oversensing. To date, little is known about the impact of electromagnetic interference (EMI) on the distinct S-ICD sensing mechanism.
A 67-year-old male patient experienced an inappropriate shock 44 months after S-ICD implantation, while guarding his grandchildren in a public swimming pool, next to a waterslide. Device interrogation revealed high-frequency signals, misinterpreted as ventricular fibrillation, followed by inappropriate therapy delivery with 80 J (Panel A). As the patient had remained conscious throughout the incident, we were able to return to the scene. The EMI of approximately 30 Hz could be reproduced (Panel B), when the patient held on to a metallic handrail next to the waterslide, which was supplied by a water pump, installed adjacent to the handrail.
Patients should be advised that EMI of the S-ICD does not only happen in close proximity to strong electromagnetic active components but may also be caused by current leakage in everyday situations. Our case report reveals a new threat, especially for young, more active patients, in which S-ICD therapy is preferably used.
The full-length version of this report can be viewed at: https://www.escardio.org/Education/E-Learning/Clinical-cases/Electrophysiology.
Author notes
Jürgen Kuschyk author contributed equally to the study.
