An Unusual Presentation of a Myocardial Crypt in Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a common inherited cardiovascular disease with prevalence of 0.2% in the population. More than 1000 mutations in more than 10 genes encoding for proteins of the cardiac sarcomere have been identified. Cardiac magnetic resonance imaging (CMR) is used to characterize left ventricular morphology with great precision in patients with HCM and it identifies unique structural abnormalities in patients with HCM. We present a case of a 56-year-old man who had positive family history of HCM who was a carrier of the genetic MYH-7 2770 G > C, exon 23 mutation. Transthoracic echocardiography showed thickening of the interventricular septum (16 mm) and in particular the basal septum. CMR confirmed the diagnosis of HCM in the anteroseptal myocardium with a thickness of 23 mm and also revealed large and deep myocardial crypts in the anterior wall. These myocardial crypts are rarely found in the so-called genotype positive and phenotype positive patients, as in our case. Also the crypts in this case are deeper and wider than those reported in other cases. So in conclusion, this case reveals an uncommon finding of a myocardial crypt at an unusual myocardial site with the unusual morphology in a patient with genotypic and phenotypic expression of hypertrophic cardiomyopathy.