Inappropriate Ventricular Fibrillation annotation and defibrillator discharge despite the same tachycardia cycle length in Ventricular Tachycardia-1 zone in an Abbott defibrillator - what is the mechanism?

Newer devices incorporate advanced algorithms to have more accurate delivery of implantable cardioverter-defibrillator therapy. Newer models of Abbott Implantable cardioverter-defibrillators like Gallant and Entrant have a new ventricular fibrillation therapy assurance algorithm. This algorithm has a proven role in avoiding under-detection of ventricular fibrillation where some of the smaller electrograms are under-sensed. We report the first case of ventricular fibrillation therapy assurance algorithm malfunction in a single chamber Entrant Implantable cardioverter-defibrillator, where the patient received inappropriate therapy. The ventricular fibrillation therapy assurance algorithm eventually had to be turned off. This article is protected by copyright. All rights reserved.