Submitral Aneurysm

Submitral aneurysm

Submitral aneurysm is a bulge through a congenital defect in the posterior portion of the mitral annulus. The aneurysm can interfere with the proper closure of the mitral valve and cause mitral regurgitation. The cavity of aneurysm can be a focus for thrombus formation and consequent thromboembolism. Arrhythmic circuits can form in the wall of the aneurysm and adjacent tissue. Rarely the submitral aneurysm can cause compression of the left circumflex coronary artery [1]. It is a cause for a bulge on the left border of the heart on chest X-ray.

Submitral aneurysms have been classified into three types by Henning et al [2]. Type I has a single localized neck while type II has multiple necks with distinct openings and type III involves the entire mitral annulus. These aneurysms have been successfully repaired surgically. In their study of twelve patients, one had type I, two had type II and three patients had type III types of aneurysms. Six patients were repaired by intracardiac approach while the remainder needed a combined intra and extracardiac approach. Re operation was needed in a third due to failure of closure of the aneurysm.

References

1. L Kontozis, J Skoularigis, D Skudicky, P Sareli. Submitral Aneurysm. Circulation. 1998; 98: 1698.
2. Henning J Du Toit, Ulrich O Von Oppell, John Hewitson, John Lawrenson, John Davies. Left ventricular sub-valvar mitral aneurysms. Interact Cardiovasc Thorac Surg 2003;2:547-51.