Ace-of-spades sign refers to the pathognomonic configuration of the left ventricle as seen in apical hypertrophic cardiomyopathy 1-3.
It consists of marked ventricular wall thickening at the apex resulting in cavity narrowing at the apex with a relatively normal appearance of the mid-ventricular to basal wall and cavity. On a longitudinal view of the left ventricle, this results in an appearance resembling a playing card spade. It can be demonstrated on echocardiography, ventriculography, and cardiac MRI.