Allied Professionals (Non-physician submissions only) -> Teaching Case Reports D-PO01 - Featured Poster Session (ID 11) Poster

D-PO01-055 - Early Detection Of S-icd Lead Displacement: Could Smart Pass Filter Yellow Alert Avert Inappropriate Therapy? (ID 900)

 S. Vyas: Nothing relevant to disclose.


Background: Lead displacements have not been documented in the large S-ICD published.
Objective: We highlight a case of S-ICD lead displacement and deactivation of SmartPass
Results: A 52 year old gentleman underwent primary prevention S-ICD implant in 2015 for hypertrophic cardiomyopathy. 3 years post implant a “yellow alert” transmission was received via remote monitoring for an untreated episode. The primary sensed electrocardiogram (S-ECG) showed myopotential oversensing, small R wave amplitude, baseline wander and a short period of TWOS. The patient was reviewed in clinic. Lead impedance was recorded as OK and an X-ray performed to assess lead position (figure 1). The device was deactivated and lead repositioned successfully. In this case, S-ECG morphology changed due to lead position, producing a small R wave less than 0.5mV, therefore the SmartPass filter was disabled automatically. The reel mechanism for macro displacement was caused by insufficient suturing of the lead or device this allows the device to rotate in the pocket, retracting the lead back to the pocket. The chest X-ray shows how the shock vector would be ineffective in this position. The lead displacement is likely to have occurred gradually, with the first warning being 2 years post implant, with the myopotential noise, which was overcome with changing vector, rather than investigating with an X-ray.
Conclusion: An alert for SmartPass deactivation could pre-empt potentially life-threatening inappropriate therapy. We recommend if a sensing change occurs &/or SmartPass sensing filter has been automatically disabled chest X-ray should be performed to exclude lead displacement.