The introduction of non-dilated left ventricular cardiomyopathy (NDLVC) represents one of the key highlights of the 2023 European Society of Cardiology guidelines on cardiomyopathies. NDLVC is defined by the presence of left ventricular systolic dysfunction in the absence of ventricular dilation and/or non-ischemic myocardial fibrosis detectable by cardiac magnetic resonance. The clinical manifestation may be arrhythmogenic, with a risk of life-threatening ventricular arrhythmias even in patients with preserved ejection fraction. The phenotypic heterogeneity and variability in clinical expression reflect the complex interplay between genetic predisposition (involving variants in genes such as FLNC, DSP, and LMNA) and environmental, epigenetic, or inflammatory factors. A synergistic approach combining comprehensive clinical and family assessment, electrocardiographic and echocardiographic findings, advanced imaging, and genetic testing enables more accurate phenotypic characterization, definitive diagnosis, and consequently, tailored therapeutic strategies.