Inappropriate implantable cardioverter-defibrillator therapy due to the detection of premature ventricular complexes

Inappropriate shocks delivered by implantable cardioverter-defibrillators may occur in 25%-40% of patients treated with these devices. This article describes a rare cause for inappropriate shocks. Two patients received inappropriate shocks due to the presence of premature ventricular complexes during attempted reconfirmation of ventricular fibrillation. Knowledge of device algorithms for detection and reconfirmation of ventricular fibrillation, designed to have a high degree of sensitivity and therefore lower specificity, allows for reprogramming to avoid fur ther inappropriate shocks.