Subcostal Short Axis View
©Walter Rasmussen, R.D.C.S.
From the Subcostal 4-Chamber view, rotate the transducer counter-clockwise until the heart is visualized in its short axis. It may be necessary to have the patient inhale and hold their breath in order to obtain the short axis images. Tilt the transducer, in order to make the view of the left ventricle as circular as possible. Adjust the gain, focus and dynamic range or compression in order to improve definition of the myocardium.
The Subcostal Short Axis is an additional window for viewing the heart from base to apex in the short axis and is particularly useful when only sub-optimal parasternal short axis images have been obtained. It is often excellent for visualizing the base of the heart and can have better alignment for CW, PW and color Doppler of the RVOT and pulmonic valve. The aortic valve is often well-visualized from the subcostal short axis and is a good backup if the parasternal short axis view of the aortic valve was of poor quality.
Color Doppler of the inter-atrial septum can help distinguish caval flow from and ASD. Often times, the pulmonic valve can be better visualized here than from the parasternal view. CW and PW Doppler of the pulmonic valve can also add to the diagnostic quality of the examination.
The subcostal short axis can sometimes allow a better image of the left ventricle at the level of the papillary muscles for the assessment of wall motion and myocardial thickness. If the subcostal images appear small on the screen use the write zoom function for magnification.
Pericardial effusion can be assessed from the subcostal short axis view and helps determine if the effusion is circumferential or localized.