FE Doppler Assessment Flashcards

Which parameter is derived from the aortic isthmus Doppler and used to assess fetal cardiac reserve?

Answer: Isthmus flow index (IFI)

The isthmus flow index (IFI) is calculated from the aortic isthmus and reflects the balance between cerebral and placental vascular resistances.

Reversed diastolic flow in the aortic isthmus indicates:

Answer: Severe hemodynamic compromise with cerebro-placental pressure reversal

Reversed diastolic flow in the aortic isthmus reflects severe hemodynamic compromise where descending aortic pressure exceeds aortic isthmus pressure throughout diastole.

Tricuspid regurgitation velocity on Doppler can be used to estimate:

Answer: Right ventricular systolic pressure

Using the modified Bernoulli equation (4v²), tricuspid regurgitation jet velocity estimates the right ventricular-to-right atrial pressure gradient.

Which Doppler finding supports a diagnosis of fetal coarctation of the aorta?

Answer: Discordant ventricular sizes with right heart dominance and aortic arch hypoplasia

Coarctation is suspected when there is right heart dominance, a hypoplastic aortic arch, and discordant ventricular sizes with left heart hypoplasia.

Pulmonary venous Doppler shows which pattern in the normal fetus?

Answer: Biphasic flow with systolic and diastolic peaks

Normal fetal pulmonary veins show biphasic forward flow with systolic (S) and diastolic (D) peaks, similar to postnatal patterns.

Which Doppler finding in the hepatic veins suggests elevated central venous pressure in the fetus?

Answer: Absent or reversed a-wave

An absent or reversed a-wave in hepatic venous Doppler reflects elevated right atrial pressure transmitted during atrial contraction.