FIG 19.7 The heart can also be described in terms of its orthogonal planes, although they are skewed relative to the long-axis planes of the body Long-axis planes cut through two chambers of the heart, along with the short-axis planes The third series of planes, in the long axis, are in the plane of the image itself They produce the so-called four-chamber cuts, as seen in Fig 19.3 Scanning from the apical window provides the two cardiac long-axis planes The coronal long-axis plane is at right angles to the inlet part of the ventricular septum and is conventionally termed the four-chamber plane (see Fig 19.3) This is the plane that best shows the anatomy of the atrioventricular connections When taken through the membranous atrioventricular septum, the section also incorporates part of the subaortic outflow tract Hence most of these cuts show more than the four basic cardiac chambers Nonetheless, the designation as a four-chamber plane is a useful one The long-axis plane at right angles to the outlet part of the septum can, by analogy to the four-chamber plane, be considered as a two-chamber plane In most cases it also includes part of the right ventricular infundibulum and illustrates more than the two basic chambers The long-axis plane basically showing two chambers is also one of the standard planes obtained from the parasternal window (Fig 19.8), together with the series of short-axis planes (Fig 19.9) When scanning from subcostal and suprasternal windows, it is no longer possible to section a normally positioned heart in its own axes, although this may be possible when the heart is abnormally positioned Instead, the usually located heart is sectioned in paracoronal and parasagittal planes relative to the axes of the body From the subcostal position, such sections produce imaging planes that are similar to, but differ subtly from, the four-chamber and short-axis planes These sections also highlight the location of the membranous septum and how the inferior part of the muscular ventricular septum separates the right ventricular inlet from the outlet of the left ventricle (Fig 19.10) These sections also show the long axis of the aortic arch, although this is probably better seen from the suprasternal window Many views must be used to obtain a complete impression of cardiac structures Despite the need for presentation and description of echocardiographic findings in terms of imaging planes, the key to successful evaluation is to obtain continuous scans from one view to another (sweeps) This allows the echocardiographer to build up a three-dimensional reconstruction from a continuous series of twodimensional parts By combining different sweeps, the entire cardiac anatomy can be imaged and reconstructed mentally FIG 19.8 Section simulating the parasternal long-axis echocardiographic cut In addition to showing the left atrium and ventricle, it also shows the infundibulum of the right ventricle FIG 19.9 Short-axis section through the ventricular mass simulating the echocardiographic parasternal short-axis cut The curved arrangement of the ventricular septum and the oblique orientation of the left ventricular papillary muscles are shown Note that, when the heart is positioned as it lies in the chest during life, these muscles are positioned inferoanteriorly and superoposteriorly