A 71-year-old male patient with a history of persistent atrial fibrillation, tachycardia-induced cardiomyopathy with severe systolic dysfunction (LVEF of 25%), external electrical cardioversion with conversion to sinus rhythm, with LVEF of 47% demonstrated by transthoracic echocardiography 2 months later, catheter ablation of atrial fibrillation (pulmonary veins isolation), ischemic stroke, ischemic cardiomyopathy (severe stenosis of the left main coronary artery treated with stent implantation), LVEF of 25%, sustained monomorphic ventricular tachycardia, implanted with a dual-chamber Biotronik Acticor 7 VR-T ICD is admitted to the Cardiology Department for an episode of palpitations accompanied by dyspnea at rest. His ECG recorded at admittance is presented in Fig. 1.