Echocardiography of the Aortic Root

The echo pattern of the aortic root is elicited by locating the typical echo of the mitral valve and then angulating the transducer medially and sometimes cephalically. The characteristic echo pattern of the aortic root consists of paired undulating signals three to five cm apart. These signals move anteriorly during systole and posteriorly during diastole. Their position is central in relation to echoes arising from the mitral and tricuspid valves, corresponding to the anatomic position of the aortic root. The movement pattern is identical to the mitral annulus, which also represents a portion of the fibrous skeleton of the heart. Lesser echoes originating between the undulating margins of the aortic root were identified as arising from the valve cusps by correlating their motion with the production of the cardiac sounds. Further support was gained by recording abnormally intense and distorted signals in patients with calcific aortic stenosis. Anatomic validation of the aortic origin of these echoes was obtained by means of ultrasonic contrast injections made during radiologic studies of the aortic root. Saline was injected in the supravalvular position during continuous echocardiographic recording and was detected as a cloud of echoes limited by the parallel signals of the aortic root. Systolic movement of the aortic cusps was accompanied by the delivery of non-contrast blood from the left ventricle which produced defects in the contrast image paralleling the excursion of the linear signals from the cusps.