Imaging cardiac morphology in hypertrophic cardiomyopathy

PURPOSE OF REVIEW: To describe new cardiac MRI (CMR) findings on cardiac structure and myocardial composition in hypertrophic cardiomyopathy (HCM). RECENT FINDINGS: Quantitative CMR assessment of replacement fibrosis and interstitial fibrosis can risk stratify HCM patients for adverse outcomes. Patients with global LVH (increased LV mass index) have more adverse outcomes. The HCM phenotype with a spiral distribution of hypertrophy entails a good prognosis. Myocardial noncompaction can be associated with HCM, as are papillary muscle and mitral apparatus abnormalities. Genotype positive, phenotype negative relatives of HCM probands may be detected by myocardial motion abnormalities. Emerging CMR methods for myocardial fiber disarray and altered myocardial stiffness may shed more light on cardiac structure, function and outcomes in HCM in coming years. SUMMARY: CMR structural features of HCM, including severity and distribution of hypertrophy and fibrosis, can augment clinical evaluation of HCM. New CMR phenotypes, associated papillary muscle, mitral leaflet and myocardial noncompaction abnormalities, role of left atrial enlargement, findings in genotype positive phenotype negative HCM, and emerging methods for the detection of myocardial fiber disarray and altered myocardial stiffness may shed light in coming years.