standardized data acquisition in transoesophageal echocardiography 27 Fig. 1.32 Mid-transoesophageal short-axis view of the aortic valve (a). Upper transoesophageal long-axis view of the ascending aorta (b). Upper transoesophageal views of the ascending aorta and pulmonary artery, as well as the superior caval vein. The short-axis view of the aortic root and the pulmonary bifurcation is displayed in grey scale (c) and colour-coded mode (d). The short-axis view of the superior caval vein and the upper right pulmonary vein is displayed in grey scale (e) and colour-coded mode (f). Additional comments in the text. mid-papillary level (0°) ( Fig. 1.33c–d). If the left ventricle is displayed centrally in the sector, the perpendicular view shows the transgastric left ventricular 2-chamber view (90°) with the apex on the left side and the mitral valve on the right side ( Fig. 1.33e–f). The inferior wall is in the near field, the anterior wall in the far field. The transgastric long-axis view can be displayed by further rotation of the probe to 100°–130° and a minor clockwise rotation of the shaft, which displays the aortic valve on the right side of the sector in the far field ( Fig. 1.34a–f). The inflow tract of the right ventricle is also visualized by the perpendicular view (90°) to the left ventricular short-axis view (0°) after centring the right ventricle in the sector before rotating ( Fig. 1.35a–d). The transgastric right ventricular longitudinal view displays the right ventricular apex on the left side and the right atrium and the tricuspid valve on the right side of the sector. A further rotation of the probe to 110°–140° and a minor rotation of the shaft enables the visualization of the inflow and outflow tracts of the right ventricle. The outflow tract and the pulmonary valve are nearly centred in the far field in this view. The transgastric short-axis view of the mitral valve is a technically difficult view. Often only an oblique view of the mitral valve can be displayed. The short-axis view of the mitral valve is achieved by slightly withdrawing the probe at 0°–20° from the mid-papillary short-axis view and simultaneous anteflexion of the probe. In this view the anterior mitral leaflet is on the left side of the sector and the posterior leaflet on the right side of the sector. The posteromedial commissure (A3/P3) is in the near field, the anterolateral commissure (A1/P1) in the far field ( Fig. 1.36a–d). A second possibility to visualize the left ventricular outflow tract is by deep intubation into the gastric fundus with consecutive anteflexion of the tip of the probe. Using this approach, the deep transgastric long-axis view at about 0° and the deep transgastric 5-chamber view can be achieved at about 120°–140° ( Fig. 1.37a–f). The deep transgastric long-axis view displays the right ventricular outflow tract on the left side of the sector, the left ventricle on the right side of the sector in the near field, and the aortic valve centrally in the far field. Sometimes the transversely intersected aortic root and proximal ascending aorta are visualized. After the documentation of the cardiac structures and the ascending aorta at the end of the transoesophageal investigation, the probe is turned into the opposite direction to the heart by rotating the shaft about 90°. Starting in the deep oesophagus at the diaphragm, the descending aorta is scanned using short-axis views (0°) during withdrawal of the probe to the upper oesophagus.
28 chapter 1 conventional echocardiography—basic principles Fig. 1.33 Mid-transoesophageal bicaval view during systole (a) and diastole (b). Transgastric short-axis view at the mid-papillary level during systole (c) and diastole (d). Transgastric 2-chamber view during systole (e) and diastole (f). Additional comments in the text. Fig. 1.34 Transgastric long-axis view during systole (a) and diastole (b), as well as the corresponding colour-coded views (c, d). The transgastric colour-coded long-axis view in a patient with hypertrophic cardiomyopathy with increased systolic (e) and diastolic flow (f). Additional comments in the text.