Inappropriate Shock Despite Successful Termination of Supraventricular Tachycardia by Antitachycardia Pacing during Charging

We present a case of a 70-year-old man who received an inappropriate implantable cardioverter-defibrillator shock for sinus tachycardia falling outside of the ventricular tachycardia zone. This occurred after termination of supraventricular tachycardia falling into the ventricular fibrillation zone by antitachycardia pacing. Particularities of the programming algorithms are reviewed.