Exploring Morphologic and Functional Variants in Hypertrophic Cardiomyopathy: An Echocardiographic and Doppler Review

Hypertrophic cardiomyopathy (HCM) is a complex and heterogeneous myocardial disorder, best evaluated with echocardiography for initial diagnosis, risk stratification, and longitudinal monitoring. This focused review explores the echocardiographic assessment of various morphologic phenotypes of HCM, emphasizing their diagnostic nuances. Distinct phenotypes, including asymmetric septal hypertrophy, concentric hypertrophy, and the less common apical HCM, present unique imaging challenges. Additionally, the review outlines essential techniques and practical tips for assessing left ventricular apical aneurysm flow patterns and dynamic intraventricular gradients. A thorough understanding of mitral valve anatomy and its role in left ventricular outflow tract obstruction is also crucial. Finally, anatomical variants of the mitral valve, papillary muscles and left ventricular myocardium are examined for their contribution to systolic anterior motion and mid-ventricular obstruction as well as for constituting additional phenotypical expressions of HCM, beyond left ventricular hypertrophy.