The Apical Window for Echocardiography
©Walter Rasmussen, R.D.C.S.
The apical window is obtained with the transducer placed at or near the cardiac apex, with the transducer face pointed superiorly and slightly rightward in order to image the heart from its apex to base. A good initial placement of the transducer is just below the left breast at the anterior axillary line, but can vary slightly toward the midline or the left side of the chest. Fortunately, an ultrasound machine is one of the best tools for finding the cardiac apex and the sonographer does not have to resort to palpation.
In difficult cases, finding an apical window can be easier if the transducer is placed initially at the parasternal long axis view and then slid toward the apex while gradually tilting the transducer face superiorly.
Once an apical window is located, orient the transducer index mark generally toward the left side of the body and compose the best possible 4-chamber view of the heart (see details below).
If only a faint image of the heart is obtained, move the transducer slightly in all directions on the chest wall to confirm that reflections of highest intensity are being obtained.
If the image is still faint or off-axis there are a few maneuvers which should be that can greatly improve the image.
Turning the patient to a steeper angle and utilizing the cutout of the echo exam table can help to bring the heart closer to the chest wall and will usually improve the image.
Perhaps the most effective technique for obtaining top quality images is working with the patient’s breath. As discussed earlier in this book, the lungs and heart move in unison and when a heart is not adequately visualized through the rib cage, expanding or compressing the lungs can move it into view. Direct the patient to take a breath in, and as the heart is pushed slightly inferiorly and medially, follow it by sliding the transducer in the same direction. While the breath is being taken in, it may also be necessary to move the transducer downward on the chest wall as much as a full intercostal space. If the image worsens with inhalation, try having the patient exhale beyond their normal exhalation point, –holding all of the extra air out of their lungs and moving the transducer to follow slightly superiorly and laterally. In many cases, a full breath is not necessary and a slight inhalation or exhalation is all that is needed to produce the best images. Take into consideration how long the patients can comfortably do the above breathing technique, eliminating the possibility of over-stressing them.
Interference from lung tissue which overlies the heart can also be an issue at the apical window. If the image is foggy and indistinct, have the patient exhale, while following with the transducer just until the image clears and then hold. Lung artifact of this type is a relatively rare technical difficulty, even in patients with lung disease. Such fogging or shadowing can also be dealt with by using the LGC gain control to dim or brighten the image from side-to-side.
Please refer to the earlier section: Cardiac Ultrasound Windows, for more detailed information about how to obtain the best possible images in difficult situations by using effective patient positioning.