“…Anatomically, the two mitral leaflets are basally attached to a fibromuscular ring in the fibrous skeleton of the heart, known as the annulus fibrosus. 19,20 The fibrous trigones, as major components of the annulus fibrosus, sit adjacent to the commissures. The more prominent right fibrous trigone (or central fibrous body) is equidistant from the tricuspid, mitral, and aortic valves, whereas the left fibrous trigone is seated between the mitral and aortic valve, towards the peripheral and most posterior portion of the fibrous skeleton.…”