Fine Ventricular Fibrillation Therapy Assurance Algorithm Failure From Low-Amplitude Far-Field Signals

Le résumé fourni par la source

BACKGROUND: The VF Therapy Assurance (VFTA) algorithm in Abbott implantable cardioverter-defibrillators (ICDs) enhances detection of fine ventricular fibrillation by utilizing far-field signals when near-field sensing is inadequate. However, this algorithm may paradoxically trigger inappropriate ICD therapy in certain electrogram phenotypes. CASE SUMMARY: A 53-year-old man with a cardiac resynchronization therapy-defibrillator for nonischemic cardiomyopathy presented after an ICD shock during light housework. Device interrogation revealed stable supraventricular tachycardia at 160 beats/min with low-amplitude far-field signals on the Coil-Can vector, triggering VFTA activation. This collapsed all detection zones into a single therapy zone, disabled supraventricular tachycardia discriminators, and delivered an inappropriate shock after only 6 beats meeting ventricular fibrillation criteria. The sensing vector was reprogrammed from Coil-Can to Tip-Can, with no recurrent inappropriate therapy on follow-up. DISCUSSION: Low-amplitude far-field signals can inappropriately activate VFTA, leading to zone collapse and discriminator suspension during supraventricular tachycardia, resulting in unwarranted therapy delivery. TAKE-HOME MESSAGE: Targeted sensing vector reprogramming may mitigate VFTA-mediated inappropriate shocks while preserving the algorithm's intended benefit for fine ventricular fibrillation detection.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.