Hypertrophic cardiomyopathy with restrictive phenotype and myocardial crypts.

This report describes a 22-year-old woman who has clinical and physiologic features of a restrictive cardiomyopathy. Magnetic resonance imaging showed myocardial delayed enhancement and interventricular septal crypts characteristic of hypertrophic cardiomyopathy (HCM). Transcatheter biopsy confirmed the diagnosis, revealing marked myocyte hypertrophy, interstitial fibrosis, and fiber disarray, which are findings consistent with HCM. A review of the literature suggests that this is the first case of HCM reported with a restrictive pattern and myocardial crypts.