The use of M-mode echocardiography to identify the true lumen in aortic dissection

Abstract

Aortic dissection is a tear in the intimal lining of the aorta, with subsequent flow of blood into a false lumen. Determining which lumen is the true lumen is often clinically important, particularly if involvement of the coronary arteries is suggested. The use of M-mode imaging on echocardiography is often underused in the diagnosis of aortic dissection 1 and determining the true lumen in aortic dissection. 2 In the vast majority of cases, the pressure and velocity in the true lumen is greater than that in the false lumen in early systole. 3 In early systole, the pressure in the true lumen increases, expanding the true lumen while compressing the false lumen. This is described as pulsating oscillations or fluttering of the intimal flap. 4 On M-mode this is easily seen as expansion of the true lumen immediately after the QRS