Based upon:
ASE Sonographer Core Curriculum Understanding the cardinal directions that are expected in each of the imaging planes will greatly simplify the sonographer's work when evaluating patients with complex congenital heart disease- particularly those patients with dextrocardia.
Dextrocardia: heart is positioned in the right chest, apex pointing rightward (as opposed to
Dextroposition: heart is positioned in the right chest, apex pointing leftward {or toward midline})
Parasternal Long Axis:
- "base" on the right side of screen
- apex of heart on left side of screen
- image is then an anterior-posterior section along the cardiac long axis- regardless of cardiac position
- if patient has dextrocardia, image should be labeled "DEXTRO" or "RSB" (for Right Sternal Border)
Parasternal Short Axis:
- 90 degrees CLOCKWISE from long axis
- patient left is on right side of screen
Apical 4-Chamber:
- patient left is on right side of screen
Subcostal Transverse:
- patient left is on right side of screen
Subcostal Short Axis:
- 90 degrees CLOCKWISE from transverse
Suprasternal Notch Short Axis:
- patient left is on right side of screen
Suprasternal Notch Long Axis:
- ascending aorta on left side of screen, descending aorta on right (regardless of laterality)
When confronted with a patient with known (or suspected) cardiac malposition, begin scanning from the subcostal transverse imaging plane. The transducer index mark and image (screen) index mark should both be oriented to the patient's LEFT:
- subcostal transverse: define absolute and relative positions of AO, IVC, and spine
- sweep (tilt) up to demonstrate the position of the heart in the chest and the direction the apex is pointing
- sweep (continue tilting) anterior to determine the AV and VA connections and positions of the great vessels
Allow yourself a few minutes at the outset of the exam to determine the cardiac position, situs, AV/VA connections- before recording an echo "officially". It is far easier to record an echo, adhering to the imaging protocol, when you already know what to expect (because you spent the time to figure it out). Lastly, it is worth mentioning that positioning- of both the patient and the sonographer- can impact the performance of the exam. Patients with dextrocardia should be optimally positioned in the right lateral decubitus position, and the sonographer should be positioned such that scanning can be comfortably performed with the patient in that position.
