The Evolving Landscape of Hypertrophic Cardiomyopathy: Phenocopies and Diagnostic Pathways in Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is an inherited myocardial disease defined by unexplained thickening and hypertrophy of ventricular myocardium. However, several other conditions-"phenocopies" or mimics-can present with a similar hypertrophic phenotype. This article details the major HCM phenocopies, including infiltrative and storage diseases (amyloidosis, Fabry, Pompe, and Danon), systemic granulomatous disease (sarcoidosis), mitochondrial disorders, physiologic hypertrophy (athlete's heart), and hypertensive heart disease and aortic stenosis. We describe their distinguishing clinical features, multimodality imaging findings, pathophysiology, and key diagnostic clues highlighting red-flag signs and recent advances in diagnostics.