Hypertrophic cardiomyopathy (HCM) is the most common genetic disease of the 
heart. HCM is characterized by a wide range of clinical expression, ranging from 
asymptomatic mutation carriers to sudden cardiac death as the first 
manifestation of the disease. Over 1000 mutations have been identified, 
classically in genes encoding sarcomeric proteins. Noninvasive imaging is 
central to the diagnosis of HCM and cardiovascular magnetic resonance (CMR) is 
increasingly used to characterize morphologic, functional and tissue 
abnormalities associated with HCM. The purpose of this review is to provide an 
overview of the clinical, pathological and imaging features relevant to 
understanding the diagnosis of HCM. The early and overt phenotypic expression of 
disease that may be identified by CMR is reviewed. Diastolic dysfunction may be 
an early marker of the disease, present in mutation carriers prior to the 
development of left ventricular hypertrophy (LVH). Late gadolinium enhancement 
by CMR is present in approximately 60% of HCM patients with LVH and may provide 
novel information regarding risk stratification in HCM. It is likely that 
integrating genetic advances with enhanced phenotypic characterization of HCM 
with novel CMR techniques will importantly improve our understanding of this 
complex disease.