Typical TOE probe positions and views. Positioning of the scanning plane is indicated on the display screen: 0° indicates the transverse view, which is orthogonal to the probe, 90° shows a longitudinal view and 180° is the mirror image of 0°. (A) Upper transoesophageal views of the aortic valve in long-axis (130−150°) and short-axis (50−75°) views. (B) Upper transoesophageal views of the great vessels and atrial appendage (counter-clockwise): transverse view of the left atrial appendage and the left upper pulmonary vein (0−30°); intermediate view of ascending aorta, left atrium and right pulmonary veins (35−45°); and, with anterioflexion of the probe, transverse view of the ascending aorta, superior vena cava and main pulmonary artery with its bifurcation are obtained (0−20°). (C) Lower-middle transoesophageal views with exemplary cross-sections corresponding to (counter-clockwise) the four-chamber view of the left ventricle. From this transducer location, right heart structures can be visualized. A right atrial longitudinal view is visualized at 115−130°. (D) Transgastric views with exemplary cross-sections corresponding to (counter-clockwise) transgastric short-axis view at mid-papillary level, transgastric two-chamber view and transgastric long-axis view of the left ventricle after passing the left liver lobe. AO, ascending aorta; IVC, inferior vena cava; LA, left atrium; LAA, left atrial appendage; LV, left ventricle; LPA, left pulmonary artery; LUPV, left upper pulmonary vein; MPA, main pulmonary artery; RA, right atrium; RPA, right pulmonary artery; RLPV, right lower pulmonary vein; RUPV, right upper pulmonary vein; RV, right ventricle; SVC, superior vena cava.