noun, plural: atrioventricular septa
The atrioventricular septum is a heart septum separating the right atrium from the left ventricle. Although the name may imply other heart septa such as between the right atrium and the right ventricle or the left atrium and the left ventricle. However, this term refers in particular to that in between the right atrium and the left ventricle.
The atrioventricular septum is made up of membranous and muscular components. There are some cases wherein defects occur involving the atrioventricular septum and the defects can be detected through the use of an echocardiogram. One of which is the atrioventricular septal defect or ASVD. It is a congenital defect characterized by an abnormal development of the membranous and muscular atrioventricular septum.1 It is characterized by a lack of a normal atrioventricular septum of the heart. It can either be complete ASVD or partial ASVD. In complete AVSD, there is a single atrioventricular valve annulus, a common atrioventricular valve, and a defect of the inlet ventricular septum.2 In partial AVSD, there is a defect in the primum or inferior part of the atrial septum but there is no direct intraventricular communication.
1 Yale University School of Medicine. (2001). Atrioventricular Septal Defects. URL: http://www.yale.edu/imaging/chd/e_av_defect/
2 Michael D Pettersen, et al. (n.d.). Pediatric Complete Atrioventricular Septal Defects URL: http://emedicine.medscape.com/article/893914-overview