# The aortic root, do we see the ‘hole’ picture?

## TL;DR

This paper discusses the aortic root's overlooked external myocardial component and suggests it may have important roles in heart development and function.

## Contribution

The paper highlights a previously ignored myocardial component of the aortic root and proposes its potential significance in cardiac embryology and evolution.

## Key findings

- The external myocardial component of the aortic root is rarely considered in anatomical and clinical studies.
- This myocardial mass may play a role in cardiac embryology and coronary dominance.
- The structure could offer physiological advantages and may have been evolutionarily selected.

## Abstract

The aortic root is the segment of the aorta between the left ventricular outflow tract and the sinotubular junction of the ascending aorta, and, on one level, is merely a tube, with a valve at its base, dynamic structures below it, and notable for having the life-limiting coronary arteries originate within its sinuses. However, we propose that the perception of the aortic root has been historically grossly over-simplified by virtue of a bias towards its internal aspect, in terms of coronary ostia and subvalvar relationships through the fibrous skeleton and in so-doing a myocardial component on the external aspect has all but been ignored. This myocardial mass, a component of the left ventricular free wall, is sometimes termed the ‘left ostial process’ but appears to be rarely, if ever, considered by anatomists, cardiologists, and surgeons alike. By virtue of its direct continuity to the aortic root and proximal left coronary artery, it may have unique roles and, at the very least, deserves greater recognition and investigation. Herein, we propose that it could play a crucial role in cardiac embryology including coronary dominance, and may afford a physiological advantage, to the extent that it may have been selected for in evolutionary terms.