Between May 2003 and May 2005 fifty six patients with obstruction of the aortic valve, ascending aorta, aortic arch and descending aorta were studied. Aortic valve obstruction was considered to be an obstruction produced by alterations in the number and morphology of the aortic leaflets, in the dimensions of the fibrous ring, thickening of the leaflets and fusion of commissures. Supravalvular aortic obstruction was defined as narrowing of the lumen immediately above the valve. This last could be localized or diffuse and involve the ascending aorta or portions of the aortic arch. Coarctation was defined as a narrowing of the descending aorta.
Transthoracic and/or transesophageal echocardiography was performed on all patients using Hewlett Packard Sonos 5500 equipment with an S3 transthoracic probe and a multiplane transesophageal probe. In some cases, particularly for cases of bicuspid aorta, sections were acquired for three-dimensional off-line reconstruction.
Aortic valve obstructions were visualized in short axis sections at the level of the great arteries, while supravalvular obstructions of the ascending aorta were assessed in parasternal long axis images. Suprasternal sections were used to view obstructions of the aortic arch and descending aorta.
In cases of poor visualization, especially in aortic valve and ascending aorta, transesophageal technique was utilized at 30–50° and 120–130°.
Off-line three-dimensional reconstruction of transesophageal images was performed by taking sections every 2° from 0° to 180° with electrocardiographic and respiratory synchronization. The data from sections in the region of interest were stored in optic discs and later transferred to a computer containing software for three-dimensional off-line reconstruction (Echo-scan, version 3.1, TomTec Gmb H, Munich, Germany), as described before .
In addition, the morphological findings of 40 heart specimens with different types of aortic obstruction from the Institute's Department of Embryology were analyzed. Each specimen was described following the guidelines of the segmental sequential system used in the diagnosis of congenital heart disease . These were atrial situs, atrioventricular and ventriculoarterial connections, morphology of atrioventricular valves, obstructions of the aortic valve, ascending aorta, aortic arch and descending aorta, as well as morphological characteristics of the ventricles, including the ventricular septum. The morphologic features of equivalent heart specimens were compared with the corresponding patient's echocardiographic images to provide the anatomic bases of the latter.