Right Ventricular and Pulmonary Outflow Abnormalities

Question 1

What does peripheral pulmonary stenosis (PPS) represent?

Answer 1

A narrowing in one or multiple regions of the branches of the pulmonary arteries

PPS can cause obstruction at the level of the main pulmonary artery, at its bifurcation, or at the more distal branches.

Question 2

What congenital cardiac anomalies may be associated with PPS?

Answer 2

• Valvar PS
• ASD
• VSD
• PDA
• Tetralogy of Fallot (TOF)

ASD: Atrial Septal Defect, VSD: Ventricular Septal Defect, PDA: Patent Ductus Arteriosus.

Question 3

Which inherited and acquired conditions are associated with PPS?

Answer 3

• Rubella
• Alagille syndrome
• Noonan syndrome
• Ehlers-Danlos syndrome
• Williams syndrome

These associations highlight the complex etiology of PPS.

Question 4

In which population is PPS often seen?

Answer 4

Newborns within the first few months of life

This typically represents a mild variant which usually resolves within the first 6 months of life.

Question 5

True or False: Peripheral pulmonary stenosis is always a severe condition.

Answer 5

False

PPS can often be a mild variant in newborns that resolves spontaneously.

Question 6

Fill in the blank: PPS may cause obstruction at the level of the main pulmonary artery, at its _______.

Answer 6

bifurcation

The obstruction can also occur at the more distal branches.

Question 7

What is DCRV?

Answer 7

Double chambered right ventricle (DCRV) is a form of congenital heart disease where the right ventricle is divided into two chambers by anomalous muscle bundles.

Question 8

What causes subpulmonary stenosis in DCRV?

Answer 8

The division of the right ventricle by anomalous muscle bundles causes subpulmonary stenosis in the region of the right ventricle and right ventricular outflow tract.

Question 9

Where can obstruction occur in DCRV?

Answer 9

Obstruction may occur adjacent to the pulmonary valve or close to the RV apex.

Question 10

Can DCRV develop over time?

Answer 10

Yes, DCRV may develop over time, especially in patients with a shortened distance between their RV moderator band and pulmonary valve.

Question 11

What condition increases the risk of developing DCRV?

Answer 11

Patients with VSDs are at a heightened risk of developing a double chambered right ventricle (DCRV).

Question 12

What is pulmonary valve stenosis (PS)?

Answer 12

A congenital condition where the pulmonary valve is dysplastic, thickened, and/or tethered, restricting blood flow from the right ventricle to the pulmonary arteries.

This condition leads to reduced blood flow to the lungs.

Question 13

What are the potential severities of pulmonary valve stenosis?

Answer 13

Severities range from very mild to severe disease.

The severity can impact clinical presentation and treatment options.

Question 14

How may pulmonary valve stenosis present in newborns?

Answer 14

As critical pulmonary stenosis, where ductal flow is essential for adequate pulmonary perfusion.

Closure of the duct in these cases can lead to inadequate pulmonary perfusion and desaturation.

Question 15

What happens if the duct closes in critical pulmonary stenosis?

Answer 15

It leads to inadequate pulmonary perfusion and desaturation that is not responsive to oxygen.

This is a critical situation requiring immediate medical attention.

Question 16

How might pulmonary valve stenosis present later in infancy?

Answer 16

As a murmur that grows louder with age, characterized as a harsh ejection systolic crescendo-decrescendo murmur.

This murmur is typically loudest over the left upper sternal border.

Question 17

What additional sound is associated with the murmur of pulmonary valve stenosis?

Answer 17

An ejection click.

The ejection click is an important auditory finding in diagnosing PS.

Question 18

What is a rare presentation of pulmonary valve stenosis?

Answer 18

Sudden collapse due to progressive right ventricular hypertrophy and sudden loss of cardiac output.

This rare occurrence can be life-threatening and requires urgent intervention.

Question 19

What percentage of patients with congenital heart disease have isolated pulmonary valve stenosis?

Answer 19

8-10%

Question 20

What percentage of siblings of patients with pulmonic stenosis will also have congenital heart disease?

Answer 20

1-2%

Question 21

Which syndromic associations are linked to valvar pulmonary stenosis?

Answer 21

• Noonan’s syndrome
• LEOPARD syndrome

Question 22

What genetic mutation affects valve leaflets in patients with syndromic associations of pulmonary stenosis?

Answer 22

Causing dysplastic valve leaflets with myxomatous tissue

Question 23

How can valvar pulmonary stenosis be classified?

Answer 23

• Based on the nature of the valve
• Based on the physical cause of the stenosis

Question 24

What types of valves can be involved in stenotic pulmonary valve conditions?

Answer 24

• Unicuspid
• Bicuspid
• Tricuspid

Question 25

What is the cause of subvalvar stenosis in pulmonary valve stenosis?

Answer 25

Muscle bundle proliferation in a pressure-overloaded right ventricle

Question 26

What is supravalvar stenosis commonly associated with?

Answer 26

* Syndromes like Noonan * Lesion complexes like tetralogy of Fallot

Question 27

Fill in the blank: Valvar pulmonary stenosis can be classified by the presence or absence of associated stenosis in the _______.

Answer 27

subvalvar or supravalvar region

Question 28

What adds a pressure load to the right ventricle?

Answer 28

Obstruction to the outflow of blood from the right ventricle ## Footnote This obstruction can be underestimated in neonates due to high pulmonary vascular resistance.

Question 29

How does pulmonary vascular resistance change with age?

Answer 29

It drops with age and is at its nadir around 6-10 weeks of age ## Footnote This drop influences the velocity of blood across the stenotic valve.

Question 30

What happens to the velocity of blood across the stenotic valve as pulmonary vascular resistance decreases?

Answer 30

The velocity of blood across the stenotic valve becomes higher ## Footnote This is important for assessing the severity of the obstruction.

Question 31

What condition can result from right ventricular hypertrophy?

Answer 31

Diastolic dysfunction of the ventricle ## Footnote This dysfunction may manifest as hepatomegaly or raised jugular venous pressure.

Question 32

What can happen in the absence of intervention for right ventricular hypertrophy?

Answer 32

High right atrial pressures and right to left shunting at any atrial septal communication ## Footnote This can lead to cyanosis.

Question 33

What is the effect of higher right ventricular pressures on the interventricular septal configuration?

Answer 33

It would be abnormal, leading to decreased efficiency of contraction of the left ventricle ## Footnote This is due to ventriculo-ventricular interactions.

Question 34

Fill in the blank: The obstruction to blood outflow from the right ventricle leads to _______.

Answer 34

a pressure load on the right ventricle

Question 35

True or False: Right ventricular hypertrophy can lead to cyanosis.

Answer 35

True

Question 36

What are potential manifestations of diastolic dysfunction due to right ventricular hypertrophy?

Answer 36

* Hepatomegaly * Raised jugular venous pressure

Question 37

How is the pressure gradient across the pulmonary valve calculated?

Answer 37

Using Bernoulli’s equation with the peak velocity of flow across the valve ## Footnote This calculation can underestimate the obstruction in cases of high pulmonary vascular resistance or pulmonary hypertension.

Question 38

What factors can be used to assess right ventricular pressure?

Answer 38

Based on the tricuspid regurgitation velocity, orientation of the interventricular septum, direction of shunting at an atrial septal communication, or a patent ductus arteriosus if present ## Footnote These factors provide insight into the hemodynamic status of the right ventricle.

Question 39

What methods are used to evaluate right ventricular systolic and diastolic dysfunction?

Answer 39

Using TAPSE or tissue Doppler imaging ## Footnote TAPSE stands for Tricuspid Annular Plane Systolic Excursion.

Question 40

What aspects of pulmonary valve morphology are assessed?

Answer 40

Number of leaflets, dysplastic appearance, doming of leaflets in systole, presence of post-stenotic dilation ## Footnote Post-stenotic dilation is typical for isolated valvar pulmonic stenosis.