Myocardial Crypts: A Prephenotypic Marker of HCM

It is more than 50 years since the first modern description of hypertrophic cardiomyopathy (HCM).1 Understanding has been driven by technology, with the first descriptions focus-ing on clinical examination, ECG changes, and histological changes from autopsy study. As technology evolved from ven-triculography, M-mode, then 2-dimensional echocardiography, and cardiovascular magnetic resonance (CMR), understand-ing has evolved and the known phenotype of the disease has extended. Recent notable examples of this have been hyper-trophy missed by echo, particularly but not exclusively at the apex, mitral valve abnormalities, apical aneurysms, and pro-posed familial criteria, where even subtle abnormalities may be adjudged significant in the context of a pretest probability of 50 % of genetic mutation carriage. In this issue of Circulation: Cardiovascular Imaging, Maron et al2 have explored the poten-tial significance of myocardial crypts. These “architectura