Double- Chambered Left Ventricle and Abnormal Papillary Muscle Formation

Abstract

Papillary muscles develop separately from mitral valve leaflet and chordae, they origin from myocardial ridge of the anterior wall and to the posterior wall of the left ventricle (LV). While chordae and mitral valve leaflets origin from a cushion tissue. The myocardial ridge gradually loosens from the ventricular wall and meanwhile the cushion tissue transforms into leaflet and chordae1. Abnormal papillary muscle formation may present a muscle bridge and divide the LV into two chambers. The most rare form is the superior inferior LV subdivision which our cases represent.