Patent Ductus Arteriosus

Question 1

What is the ductus arteriosus?

Answer 1

A blood vessel in fetuses connecting the pulmonary artery and aorta, allowing blood to shunt away from developing lungs in utero.

Question 2

What is a patent ductus arteriosus (PDA)?

Answer 2

A condition where the ductus arteriosus remains open after birth, especially common in premature infants.

Question 3

What typically happens to the PDA shortly after birth?

Answer 3

It usually closes due to smooth muscle contraction and cellular migration within 24-48 hours.

Question 4

What follows the functional closure of a PDA?

Answer 4

Anatomic closure and ligamentous formation occur over the subsequent 2-3 weeks.

Question 5

What factors can influence the presentation of a PDA?

Answer 5

Size, associated lesions, and the relationship of pulmonary and systemic vascular resistances.

Question 6

What are the recommended methods for closing a PDA?

Answer 6

Pharmacotherapy (NSAIDs), surgical ligation, or trans-catheter device occlusion.

Question 7

What is the incidence of isolated PDA?

Answer 7

1 in 2,000 live births.

Question 8

What percentage of congenital heart disease does PDA account for?

Answer 8

5-10%.

Question 9

What is the estimated incidence of silent PDAs?

Answer 9

As high as 1 in 500.

Question 10

What is the female to male ratio for PDA occurrence?

Answer 10

2:1.

Question 11

In which population is PDA more common?

Answer 11

Premature infants.

Question 12

What is the likelihood of PDA occurring in subsequent offspring of a family with PDA?

Answer 12

~3%.

Question 13

Which chromosomes have been suggested as areas of interest for genetic factors related to PDA?

Answer 13

Chromosomes 12 and 16.

Question 14

Name a few genetic syndromes associated with increased frequency of PDA.

Answer 14

• Trisomy 21
• Carpenter’s syndrome
• Char syndrome
• Holt-Oram syndrome
• Incontinentia pigmenti

Question 15

True or False: PDA can be present in multiple family members.

Answer 15

True.

Question 16

Fill in the blank: The ductus arteriosus allows blood to shunt away from the _______ while in utero.

Answer 16

developing lungs.

Question 17

What are the five types of patent ductus arteriosus according to the Krichenko classification?

Answer 17

Type A, Type B, Type C, Type D, Type E

Types are determined by angiographic appearance.

Question 18

Describe Type A patent ductus arteriosus.

Answer 18

Prominent aortic ampulla with a constricted pulmonary end.

Question 19

Describe Type B patent ductus arteriosus.

Answer 19

Large width with a very short length.

Question 20

Describe Type C patent ductus arteriosus.

Answer 20

Long and without any evidence of constriction.

Question 21

Describe Type D patent ductus arteriosus.

Answer 21

Complicated course with potentially multiple areas of constriction.

Question 22

Describe Type E patent ductus arteriosus.

Answer 22

Extended length with a more remote constriction.

Question 23

What can hemodynamics differ based on?

Answer 23

Size and relationship between pulmonary and systemic vascular resistances

Question 24

What is the most common hemodynamic derangement?

Answer 24

Left-to-right shunting resulting in pulmonary overcirculation and left heart dilation

Question 25

What may prolonged left-to-right shunting lead to?

Answer 25

Pulmonary vascular disease with increased pulmonary vascular resistance

Question 26

What condition may develop if pulmonary vascular resistance exceeds systemic resistance?

Answer 26

Eisenmenger’s Syndrome

Question 27

What should right to left shunting across the PDA raise concern for?

Answer 27

Elevated pulmonary vascular resistance

Question 28

What is a contraindication to closure of the PDA?

Answer 28

Right to left shunting across the PDA

Question 29

Fill in the blank: The most common hemodynamic derangement is related to _______.

Answer 29

left-to-right shunting

Question 30

What is the purpose of the Parasternal Long Axis view in transthoracic echocardiography?

Answer 30

Allows for 2D measurement of the PDA at the pulmonary end and provides a good angle for Doppler interrogation ## Footnote PDA stands for Patent Ductus Arteriosus, a heart defect that affects blood flow.

Question 31

What can be visualized in the Parasternal Short Axis view?

Answer 31

Both main pulmonary artery and aorta when swept superiorly, along with color Doppler to determine directionality of flow within the PDA ## Footnote Short axis imaging can also reveal small PDAs primarily visible by a jet with retrograde flow.

Question 32

What is the significance of the Apical 4 Chamber view?

Answer 32

Important to assess for evidence of left atrial and/or left ventricular dilation secondary to volume overload

Question 33

What does Doppler of the abdominal aorta in the Subcostal view show?

Answer 33

Flow reversal in diastole due to runoff into the PDA

Question 34

What does the Suprasternal notch view allow for in echocardiography?

Answer 34

Evaluation for the presence and directionality of shunting across the PDA

Question 35

What type of probes are recommended for optimizing echocardiography resolution?

Answer 35

High-frequency probes with small sector width

Question 36

What is the preferred duration for clips in transthoracic echocardiography?

Answer 36

3-5 beat clips are preferred

Question 37

True or False: Still frames should be avoided in transthoracic echocardiography.

Answer 37

True