(16) Congenital Defects of the Right Heart

What is the most common cause of congenital pulmonary stenosis?

Congenital malformation of cusps

In which age group is congenital pulmonary stenosis most common?

Pediatric patients

What are two conditions that may cause acquired pulmonic stenosis in adults?

Carcinoid syndrome or rheumatic disease

What ventricular change is commonly demonstrated due to the outflow obstruction in pulmonary stenosis?

Right ventricular hypertrophy

Valvular pulmonic stenosis is commonly associated with which maternal infection?

Maternal rubella

Besides maternal rubella, list three syndromes or conditions associated with valvular pulmonic stenosis.

Turner Syndrome, Noonan Syndrome and polycythemia vera

Peripheral pulmonary artery stenosis is commonly associated with which syndrome?

William syndrome

Which congenital heart defect is specifically associated with infundibular pulmonic stenosis?

Tetralogy of Fallot

Infundibular stenosis in Tetralogy of Fallot is usually associated with what other defect?

VSD

What is recommended for patients with moderate to severe pulmonic stenosis before becoming pregnant?

The stenosis should be corrected

Why can pregnancy cause significant complications for patients with moderate to severe pulmonic stenosis?

The increase in flow volume associated with pregnancy

List five typical symptoms of pulmonic stenosis.

Dyspnea on exertion, shortness of breath, chest pain, syncope, and fatigue

Which two transducer positions best demonstrate pulmonic stenosis (PS)?

Left parasternal and subcostal

Which echo view offers the best insonation angle to assess velocity across the pulmonary valve?

PSAX view

The sonographic appearance of pulmonic stenosis is similar to the appearance of which other valve stenosis?

Aortic stenosis

What specific M-mode finding is seen in pulmonic stenosis?

Significant increase in “a” wave

How do the leaflets of the pulmonary valve typically appear in stenosis during systole?

Leaflets thickened with systolic doming

In which view should right ventricular wall thickness be measured for pulmonic stenosis?

Subcostal view

What happens to the main pulmonary artery (MPA) in pulmonic stenosis and why?

The MPA is dilated due to an eccentric stenotic jet

What is the Peak Systolic Velocity (PSV) range for mild pulmonic stenosis?

$$0.9 - 3\,m/s$$

What is the PSV range for moderate pulmonic stenosis?

$$3 - 4\,m/s$$

What Peak Systolic Velocity indicates severe pulmonic stenosis?

$$>4\,m/s$$

What Peak Pressure Gradient (PPG) is associated with severe pulmonic stenosis?

$$PPG > 64\,mmHg$$

What is the definition of pulmonary atresia?

Absence of the pulmonary valve opening

In pulmonary atresia, how is the pulmonary artery supplied with blood?

By the ductus arteriosus

If there is no VSD in pulmonary atresia, what must be patent for blood to reach the left heart?

A PFO or small ASD

In pulmonary atresia, why can systemic venous return entering the RA not exit the RV through the normal route?

Lack of an opening to the MPA

In pulmonary atresia with a VSD, logic suggests deoxygenated blood moves from RA to RV and then where?

Through the VSD into the LV and out the aorta

In pulmonary atresia with a VSD, how does blood reach the pulmonary arteries for oxygenation?

A PDA moves blood from the descending aorta to the pulmonary arteries

What is the direction of the PDA shunt in pulmonary atresia cases?

Left to right shunt

Describe the size and shape of the RV in pulmonary atresia.

Small, slit-like RV

What happens to the left heart structures in pulmonary atresia?

They become dilated

What is the sonographic indicator of flow reversal in the MPA in pulmonary atresia?

Flow from the PDA backfills the main pulmonary artery

What is the name for pulmonary atresia when combined with a VSD and overriding aorta?

Pseudotruncus

How can one differentiate pseudotruncus from truncus arteriosus?

Locate the pulmonary branch artery origins

What does the Blalock-Taussig shunt connect?

The subclavian artery to the pulmonary artery

What is the primary objective of the Fontan procedure?

Venous return goes directly to the lungs

What occurs during Part 1 (Glenn shunt) of the Fontan procedure?

Connection of the SVC to the right pulmonary artery

What occurs during Part 2 of the Fontan procedure?

The IVC is connected by a conduit to the right pulmonary artery

What is tricuspid atresia?

Absence of the opening in the tricuspid valve

What echocardiographic feature is found between the RA and RV in tricuspid atresia?

An echogenic plate-like structure

Describe the RV and RA in tricuspid atresia.

Hypoplastic RV with dilated RA

What is a common associated finding with tricuspid atresia to facilitate blood flow?

VSD

What must be present in tricuspid atresia to allow flow from the right atrium to the left atrium?

PFO

What happens when the ductus arteriosus closes in a patient with tricuspid atresia?

Deoxygenated flow can no longer reach the pulmonary artery for oxygenation

Which views are best for evaluating tricuspid atresia?

Apical or subcostal 4 chamber views

Why might a palliative pulmonary artery banding be performed before a full tricuspid atresia correction?

To reduce flow to the lungs in cases with a large VSD

What occurs in Part 1 of the Norwood procedure?

Atrial septectomy and Blalock Taussig shunt

What occurs in Part 2 of the Norwood procedure?

Glenn shunt (connect SVC to the right pulmonary artery)

What occurs in Part 3 of the Norwood procedure?

Fontan procedure (IVC connected by a conduit to the right pulmonary artery)

What is the primary malformation in Ebstein Anomaly?

Tricuspid valve leaflet(s) are more inferior and toward the apex of the heart

List three symptoms of right heart failure associated with Ebstein Anomaly.

Pedal edema, hepatomegaly, and ascites

What is the best echocardiographic view to diagnose Ebstein Anomaly?

Apical 4

In Ebstein Anomaly, what is the measurement for abnormal displacement between the MV and TV insertion sites?

$$\text{Insertion sites are } >20\,mm \text{ or } 8\,mm/m^2 \text{ apart}$$

Are the tricuspid valve annulus and leaflets both displaced in Ebstein Anomaly?

No, only the leaflets are displaced; the annulus is in the normal position

What does the "atrialized" portion of the RV cause in Ebstein Anomaly?

A very large right atrium

Where does the severe tricuspid regurgitation originate in patients with Ebstein Anomaly?

Closer to the apex than normal

How does the left ventricle appear in Ebstein Anomaly?

Small "D" shaped

What type of ASD is usually associated with Ebstein Anomaly?

Secundum ASD

What is the direction of the shunt in Ebstein Anomaly and why?

Right to left due to significantly increased right heart pressures

What percentage of Ebstein Anomaly patients also have Wolff-Parkinson-White?

$$30\%$$

What is the name of the procedure that can be performed to repair the TV in Ebstein Anomaly?

Cone procedure

What is Eisenmenger Syndrome?

A condition where chronic left to right shunting leads to reversed (right to left) shunting due to high RV pressure

What is the RVSP threshold in Eisenmenger Syndrome?

$$RVSP > 120\,mmHg$$

Where does blood from the left arm drain in persistent left SVC?

Directly into the coronary sinus through the brachiocephalic vein

What is the primary sonographic finding for persistent left SVC?

Significantly dilated coronary sinus

Between which two structures does the dilated coronary sinus appear in the PLAX view?

Between the LA and the descending aorta

Where should you image to view the vertical vein longitudinally in relation to the aortic arch?

Suprasternal notch

What is the best view for a contrast exam when evaluating persistent left SVC?

Apical 4 chamber view

If persistent left SVC is present, where does saline contrast fill first?

The coronary sinus (before the right atrium)

What is an aortopulmonary window?

A direct communication between the ascending aorta and the main pulmonary artery

What flow abnormality is seen in the descending thoracic aorta with an aortopulmonary window?

Diastolic flow reversal

What type of murmur is associated with an aortopulmonary window?

Continuous murmur

How soon should the Patent Ductus Arteriosus (PDA) close after birth?

In $2 - 3\,weeks$

What is the formula for calculating systolic pulmonary artery pressure using PDA flow?

$$\text{Systolic BP} - 4(\text{PDA PSV})^2$$