|Interior of right side of heart. (Septomarginal trabecula visible at bottom right, but not labeled.)|
|Gray's||subject #138 532|
The septomarginal trabecula (also known as moderator band) is a muscular band of heart tissue found in the right ventricle. It is well-marked in sheep and some other animals, and frequently extends from the base of the anterior papillary muscle to the ventricular septum.
This septomarginal trabecula is important because it carries part of the right bundle branch of the AV bundle of the conduction system of the heart to the anterior papillary muscle. This shortcut across the chamber of the ventricle seems to facilitate conduction time, allowing coordinated contraction of the anterior papillary muscle; (see electrical conduction system of the heart).
From its attachments it was thought to prevent overdistension of the ventricle, and was named the "moderator band".
See also 
- 1328873532 at GPnotebook
- septomarginal+trabecula at eMedicine Dictionary
- Videos and photos of moderator band
- Photo of "septomarginal trabiculation" at acc.org
- Photo with caption "moderator band" at tjc.edu