Type I mitral regurgitation results from valvular lesions such as vegetation, leaflet perforation and abscess.

Aortic valve endocarditis with large vegetations and annular abscess (left image) with a Kissing lesion of the anterior mitral leaflet (right video)

Type II mitral regurgitation

In type II dysfunction, the responsible valvular lesion is chordae rupture. The direction of the jet is opposite to the prolapsing segment. In native mitral endocarditis, an isolated lesion is rare. Patients often present with a combination of lesions which may include perforation of the anterior leaflet (type I valvular dysfunction) in association with posterior leaflet prolapse secondary to rupture chordae (type II dysfunction). Typically, one or more vegetations may also be present.