Mixed Deck — All FE Topics Flashcards

A z-score of −2.0 for the aortic valve annulus diameter means the measurement is:

Answer: 2 standard deviations below the mean for gestational age

A z-score of −2.0 means the aortic annulus is 2 standard deviations below the expected mean for that gestational age or fetal weight, indicating significant hypoplasia.

Which view best demonstrates the relationship of the pulmonary veins to the left atrium in fetal echocardiography?

Answer: Four-chamber view with posterior angulation

Angling the transducer posteriorly from the four-chamber view allows visualization of pulmonary vein insertion into the posterior left atrium.

Which embryonic structure is the origin of the sinus node and contributes to the superior vena cava?

Answer: Sinus venosus

The sinus venosus, the most caudal part of the primitive heart tube, gives rise to the sinus node, the coronary sinus, and incorporates into the posterior right atrium.

Which M-mode measurement is used to calculate the cardiothoracic ratio in fetal echocardiography?

Answer: Maximum cardiac diameter compared to thoracic diameter at the same level

The cardiothoracic ratio is obtained by dividing the maximal cardiac diameter by the thoracic diameter measured in the same transverse plane.

Which imaging plane provides the best view of the four chambers of the fetal heart?

Answer: Transverse four-chamber view

The four-chamber view is the standard plane used to evaluate the size and symmetry of the atria and ventricles.

In fetal circulation, what approximate percentage of combined ventricular output is directed through the ductus arteriosus?

Answer: 50–60%

Approximately 50–60% of combined cardiac output crosses the ductus arteriosus because fetal pulmonary vascular resistance is high and very little blood enters the lung circulation.

Which statement about fetal cardiac screening at 18–22 weeks gestation is correct?

Answer: Standard obstetric ultrasound should include four-chamber and outflow tract views

Current guidelines recommend that standard obstetric ultrasound at 18–22 weeks include both four-chamber and outflow tract views to improve CHD detection rates.

The normal peak systolic velocity in the fetal middle cerebral artery (MCA) is used in conjunction with fetal echocardiography to assess for:

Answer: Fetal anemia and high-output cardiac states

Elevated MCA peak systolic velocity (>1.5 MoM) indicates fetal anemia, which causes increased cardiac output detectable on echocardiography.

Which is the most common fetal cardiac arrhythmia encountered in clinical practice?

Answer: Premature atrial contractions (PACs)

Premature atrial contractions (PACs) are the most common fetal arrhythmia, usually benign and resolving spontaneously.

What does pulsatility in the umbilical vein waveform indicate?

Answer: Elevated right atrial pressure or cardiac insufficiency

Umbilical vein pulsatility indicates transmission of right atrial pressure waves through the ductus venosus, suggesting cardiac insufficiency or elevated venous pressure.

Which finding on fetal echocardiography suggests cardiac dysfunction in a hydropic fetus?

Answer: Cardiomegaly with cardiothoracic ratio >0.50

A cardiothoracic ratio greater than 0.50 indicates cardiomegaly, which is commonly seen with cardiac dysfunction and heart failure in hydropic fetuses.

When counseling parents after diagnosis of a major congenital heart defect, which team member is essential?

Answer: Pediatric cardiologist and maternal-fetal medicine specialist

Multidisciplinary counseling involving both pediatric cardiology and maternal-fetal medicine is essential for accurate prognosis, management planning, and parental support.

The primum atrial septal defect results from incomplete fusion of which two structures?

Answer: Septum primum and endocardial cushions

An ostium primum ASD occurs when the inferior edge of septum primum fails to fuse with the endocardial cushions, leaving a defect at the atrioventricular junction.

Untreated sustained fetal SVT is most likely to lead to which complication?

Answer: Non-immune hydrops fetalis

Sustained SVT can cause high-output heart failure, leading to non-immune hydrops fetalis if untreated.

In the normal fetus, pulmonary vascular resistance is:

Answer: Higher than systemic vascular resistance

Fetal pulmonary vascular resistance is high due to fluid-filled lungs and hypoxic vasoconstriction, directing blood away from the pulmonary circulation.

Which of the following best describes the recommended screening approach when a prior sibling had hypoplastic left heart syndrome (HLHS)?

Answer: Fetal echocardiography is strongly indicated due to ~2-4% recurrence risk

HLHS has a recurrence risk of approximately 2-4% in subsequent siblings, warranting targeted fetal echocardiography at 18-22 weeks.

A fetal echocardiogram reveals the liver on the left, stomach on the right, and apex of the heart pointing to the right. This is best described as:

Answer: Situs inversus totalis

Situs inversus totalis is a complete mirror-image arrangement of all thoracoabdominal organs including the heart apex pointing right.

Most premature atrial contractions (PACs) in the fetus are:

Answer: Conducted to the ventricles

Most PACs are conducted, producing an early ventricular beat, though some may be blocked depending on timing and AV node refractoriness.

In a fetus with confirmed Turner syndrome (45,X), which cardiac lesion should be specifically investigated on fetal echocardiography?

Answer: Bicuspid aortic valve and coarctation of the aorta

Turner syndrome (45,X) is classically associated with left-sided obstructive lesions, particularly bicuspid aortic valve (~30%) and coarctation of the aorta (~10-15%).

Which echocardiographic view is used to demonstrate that the two great arteries arise from separate ventricles in the normal fetus?

Answer: Long-axis left ventricular outflow tract view

The long-axis LVOT view shows the aorta arising from the left ventricle, crossing beneath the pulmonary artery, confirming normal ventriculo-arterial concordance.