Fig. 1

Annular size measurement using the enlarged view of the mid-oesophageal short axis (approximately 30° to 50°). The short-axis views of the aortic valve are generated at the insertion of the cusps in early systole. Red circles identify the thickened parts at the sites of peripheral attachment of the zones of apposition between the aortic valve leaflets. They represent also the vertices of the interleaflet triangles. LCC: left coronary cusp, RCC: right coronary cusp, NCC: non-coronary cusp