Case 6 — Echocardiograms and Doppler Studies

A contrast echocardiogram was performed by injecting agitated saline into a peripheral vein and watching the microbubbles traverse the heart. The microbubbles appeared in the right heart but none were seen in the left heart or aorta. Subsequently, the ultrasound transducer was placed over the caudal abdomen and the aorta identified above the bladder. Agitated saline was again injected. No microbubbles were identified in the caudal aorta, but the image was not perfect and so some doubt existed as to the validity of this test. Further echocardiographic studies were then undertaken.

Echocardiogram from the right side showing a very large pulmonary artery (PA) with a structure (S) opening into it. The structure appears as a large rounded communication between the PA and an adjacent vessel.
Echocardiogram showing a very large pulmonary artery (PA) with a structure (S) that opens into it.
Color flow Doppler echocardiogram showing flow through the large structure (S) from the pulmonary artery (PA) into the aorta (AO). The flow is depicted in homogeneous blue, indicating laminar flow away from the transducer. At the aortic end, the color turns gold where flow velocity exceeds the Nyquist limit of 0.34 meters per second.
Color flow Doppler showing flow through the structure (S) from the pulmonary artery (PA) into the aorta (AO). The homogeneous blue indicates laminar flow away from the transducer; the gold at the aortic end marks flow exceeding the Nyquist limit (0.34 m/s).
Pulsed wave Doppler tracing with the cursor placed within the ductus-like structure. Flow velocity is very low but peaks in systole, directed away from the transducer (below the baseline), flowing from the pulmonary artery toward the aorta. Some low-velocity diastolic flow is also present.
Pulsed wave Doppler cursor placed within the structure. Flow velocity is very low, peaking in systole below the baseline (away from the transducer, from the pulmonary artery toward the aorta). Some low-velocity diastolic flow is also present.
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