Figure 4 (A) The comparison between 2D‐TEE (Doppler‐derived two‐dimensional transthoracic echocardiography), RT3D (volumetric real‐time three‐dimensional echocardiography) and TEE (planimetry by transoesophageal echocardiography) to yield the clinical classification of the severity of AS (aortic stenosis). The numbers in the bars represent the actual number of patients according to the grade of AS. (B) Intraobserver and interobserver differences in aortic valve area (AVA) measurements by 3D/2D (3D‐guided two‐dimensional method), RT3D and TEE.