Anatomic Position of Heart Valves

PA and lateral chest radiographs demonstrate anatomic position of three heart valves, A = aortic, M = mitral and T = tricuspid, in a patient with rheumatic valve disease. Note that the tricuspid prosthesis is an annuloplasty.

Facts

• The three heart valves (aortic, mitral and tricuspid) commonly overlap each other on frontal radiograph. Correct radiographic identification can be difficult.
• To differentiate the mitral from aortic valve on lateral view, one draws a line from the junction of the sternum and diaphragm to the carina. This line normally intersects aortic valve*. The valve below the line is mitral valve. The tricuspid valve is the one to the mitral valve.
• Without a lateral view, the best criterion for use in differentiating between aortic and mitral prostheses is the direction of flow (discernable in Starr-Edwards and most Bjork-Shiley prostheses). Orifice (en face or in profile) and orientation (vertical or horizontal) of prosthesis are less reliable.

* This may not always be true in patients who have deformed anterior chest wall or markedly enlarged right ventricle.

Our patient's mitral and aortic prostheses are disc type, so their direction of flow was not discernable.

Reference:

1. Gross BH, Shirazi KK, Slater AD. Differentiation of aortic and mitral valve prostheses based on postoperative frontal chest radiographs. Radiology 1983;149:389-391.

2. Miller SW, Boxt LM, Abbara S. Cardiac Imaging the Requisites, 3rd edition, 2009.