EP-SCOPE is a prospective, multicentric, non-randomized pilot study that aims to estimate the risk of life-threatening ventricular arrhythmia through use of advanced electrophysiological studies in patients with ischemic or non-ischemic cardiomyopathy with left ventricular ejection fraction (LVEF) \<50% and risk factors of ventricular arrhythmia, otherwise not considered for implantation of an implantable cardioverter defibrillator (ICD). The objective is to assess the effectiveness of a risk stratification strategy based on detailed electrophysiological exploration of the left ventricle and programmed ventricular stimulation.