Subcutaneous implantable defibrillator: State-of-the art 2013

Figure 3 Subcutaneous implantable cardioverter-defibrillator electrogram showing a sustained monomorphic ventricular tachycardia that is terminated by a shock (lightning symbol). The subcutaneous implantable cardioverter-defibrillator (S-ICD) system uses an 18/24 interval criterion for tachycardia detection (T) which is reconfirmed after capacitor charging (C), but before shock delivery, to exclude the presence of non-sustained tachyarrhythmias. S: Sensed event not classified as tachycardia.