Question

A 35 year old male presents for a follow up echocardiogram due to a history of a secundum ASD that was diagnosed two years ago. You are viewing the atrial septum in the subcostal view and apply color flow doppler. No flow is detected across the septum. Which of the following could explain the lack of flow displayed across the defect?

A) The color doppler PRF is set too high
B) PW doppler is required to assess flow across the atrial septum because color is not well displayed in the subcostal view of the septum
C) The color doppler map is inverted
D) Secundum ASD's commonly close spontaneously and the defect most likely has healed

Answer 1

During a follow-up echocardiogram, various factors could explain the absence of detectable flow across a previously diagnosed secundum ASD, such as incorrect Doppler settings, the need for different Doppler modalities, or spontaneous closure of the defect.

Step-by-step explanation:

A 35-year-old male with a history of a secundum atrial septal defect (ASD) undergoes a follow-up echocardiogram. During the subcostal view examination using colour flow Doppler, no flow is detected across the septum. The following explanations could account for this observation:

• The colour Doppler Pulse Repetition Frequency (PRF) is set too high, which could prevent the detection of lower velocity blood flow across the septum.
• Pulsed-Wave (PW) Doppler might be necessary to assess the flow across the atrial septum in some views because colour Doppler might not sufficiently display the flow in the subcostal view.
• The color Doppler map may be accidentally inverted, which could lead to erroneous conclusions about flow directions and presence.
• Secundum ASDs have been known to close spontaneously over time, and it is possible that the defect has healed, leading to an absence of detectable flow across the atrial septum.