Muscle
Moderator band
Right ventricular bridge carrying conduction tissue
High-yield
This is a useful marker of right ventricular morphology. Its right bundle/Purkinje connection is more important than the old suggestion that its purpose is to prevent overexpansion.
Overview
A muscular band extends from the right ventricular septal region toward the anterior papillary muscle and free wall. It contains conducting fibers that help activate the right ventricle, along with ordinary working myocardium.
Reference facts
- Origin
- Right ventricular septal region, associated with the septomarginal trabeculation
- Insertion
- Anterior papillary muscle region and adjacent right ventricular free wall
- Innervation
- Autonomic fibers supply its myocardium; specialized right bundle/Purkinje tissue also traverses it
- Action
- Participates in ventricular contraction and distributes rapid activation toward the right ventricular wall
- Blood supply
- Septal perforating arterial branches, usually from the anterior interventricular artery
Clinical correlation
Purkinje-related ventricular ectopic beats can originate in this band. In some patients they trigger serious ventricular arrhythmias, although a visible normal band is not itself evidence of disease.
Frequently asked questions
What does the moderator band do?
The moderator band participates in ventricular contraction and distributes rapid activation toward the right ventricular wall.
What nerve innervates the moderator band?
Autonomic fibers supply its myocardium; specialized right bundle/Purkinje tissue also traverses it.
Where does the moderator band attach?
Origin: Right ventricular septal region, associated with the septomarginal trabeculation. Insertion: Anterior papillary muscle region and adjacent right ventricular free wall.
What is the blood supply of the moderator band?
The moderator band is supplied by the septal perforating arterial branches, usually from the anterior interventricular artery.