Answer to quiz: A round cyst-like structure in the right atrium Correct answer is #2: Atrial septal aneurysm (ASA)
protruding from the left atrium into the right atrium. This conclusion became clear after receiving other
echocardiographic images, particularly the apical fourchamber view (Fig. 1). It is possible to notice on this
image that in fact this formation is not a cyst, but a deep protrusion of the atrial septum in its central part
from left to right. This protrusion remains practically the same by its size during both systole and diastole.
Using the color Doppler we could not visualize the shunt of blood in the atrium from left to right side or
vice versa, so it was not possible to prove the presence of a patent foramen ovale (PFO) or atrial
septal defect, which often happens in such cases.