Anomalies of the Right Ventricular Outflow Tract & Pulmonary Artery

List the 5 categories of RV outflow tract anomalies. Which is the Most common type is what?

• Pulmonary valve stenosis - valve stenosis is the most common*

• Subpulmonary stenosis

• Supravalvular pulmonary valve stenosis

• Branch PA stenosis

• Pulmonary atresia with intact ventricular septum - AKA single ventricle

How common is pulmonary valve stenosis, and is it usually congenital or acquired?

• ___th most common congenital heart lesion

• Almost always _______ and if its the other one what is caused by list 2

• 4th most common congenital heart lesion

• Almost always congenital

• May rarely be acquired from carcinoid or rheumatic disease

When can pulmonary valve stenosis present, and what determines when it presents?

It can present from in _____through _____, depending on the degree of ______.

It can present from in utero through adulthood, depending on the degree of stenosis.

Is pulmonary valve stenosis usually isolated, and list the 2 CHDs associated with it.

It is usually isolated.

Associated CHDs:

1. Tetralogy of Fallot

2. DORV

List the 3 syndromes/conditions associated with pulmonary valve stenosis.

• Noonan syndrome

• Rubella

• Williams syndrome — associated with branch stenosis

What happens to the measured severity of PV stenosis when the PDA closes, and what may be used before then?

• After the PDA closes, the gradient better shows the severity (b/c the PVR drops)

• Before that, you may need to rely on the Severity of RV hypertrophy First

Is progression of pulmonary valve stenosis common after the first year of life? & What view is the best to view RVOT obstruction list 3? & what is the best View?

No. Progression after the first year is rare.

What view is the best to view RVOT obstruction: SAX #1 view , PLAX, Subcostal, RVOT view

Pulmonary valve stenosis includes:

What happens when pulmonary valve _________are fused, underdeveloped, or absent?

LIST 2

• Pulmonary valve commissures are fused, underdeveloped, or absent

• The valve opening / orifice opening becomes limited

• The valve may appear dome-shaped

What are dysplastic pulmonary valves associated with?

Sinotubular narrowing.

What abnormal numbers of pulmonary valve cusps may occur List 3, and what are they associated with? list one congential and two leisons

• Unicuspid - more stenotic

• Bicuspid - more stenotic

• Quadricuspid - more regur

They may be associated with Tetralogy of Fallot and with stenosis and regurgitation.

How does the severity of PV stenosis relate to RV hypertrophy?

• Mild–moderate PS → normal to mild RV hypertrophy

• Moderate RVH → Moderate PS

• Severe PS → severe RV hypertrophy (Wall stress)

The degree of stenosis is directly related to the degree of hypertrophy.

What is common with PV stenosis, and does PA size correlate with stenosis severity?

• Post-stenotic dilation is common

• No, the severity of stenosis does not correlate with the size of the main PA

Simple way to remember:

A large main PA does not automatically mean severe pulmonary stenosis, and a normal-sized main PA does not rule out severe stenosis.

What happens to the RVOT as hypertrophy becomes severe?

• Outflow tract is severely affected by degree of

  _______and will cause an ________

• RVOT becomes _____

• Less ______during systole

• Decreased ______during diastole

• Pressure ________

• May eventually produce a ______-to-______shunt

• Outflow tract is severely affected by degree of hypertrophy and will cause an obstruction

• RVOT becomes stiff

• Less contractile during systole

• Decreased recoil during diastole

• Pressure increases

• May eventually produce a right-to-left shunt

(infundiublum becomes thick can lead to subpulmonic obstruction double obstruction)

Decreased recoil during diastole means the right ventricle (RV) cannot relax and spring back to its normal shape as easily after contracting.

Why does this happen?

1. Pulmonary stenosis causes pressure overload in the RV.

2. The RV muscle becomes thicker (RV hypertrophy).

3. The thickened RV becomes stiffer and less compliant.

4. During diastole, the RV cannot relax and expand as easily to fill with blood.

5. This causes increased RV filling pressure.

List the 9 clinical findings of pulmonary valve stenosis.

1. May be symptomatic or asymptomatic ? which one?

2. What murmur

3. List 5 clincial presentation

4. Sudden _____

5. RV what and ____-axis deviation on EKG

6. _______and ______with critical PS

• May be asymptomatic (b/c PS may be mild)

• Systolic ejection murmur

• Exertional dyspnea

• Fatigue

• Chest pain and/or syncope

• CHF

• Sudden death

• RVH and right-axis deviation on EKG

• Hypoxemia and cyanosis with critical PS

(S.A.D also applys here)

Hypoxemia means a low level of oxygen in the blood, specifically arterial blood.

Echo Assessment:

List the 4 main things evaluated when imaging the pulmonary valve/RVOT.

____ size and anatomy- using what view _____ parasternal

what finding / shape of the PV leaflets

Level of what

______ through the outflow tract and valve

• Valve size and anatomy — high parasternal

• Doming of the PV leaflets

• Level of obstruction

• Gradient through the outflow tract and valve

List the 5 additional findings evaluated on echo with PV stenosis.

List 2 for the PA size and what lesion

List 2 for RV

what TV findings and RA findings

what finding do you see of the septem

and two shunt flow direction

• Main and branch PA size and PI

• RV hypertrophy and RV function

• TR and RA dilation

• Septal flattening (b/c of pressure of the RVH)

• ASD and PDA flow direction

What additional study may be needed when evaluating an ASD?

Bubble study

What is the primary repair for pulmonary valve stenosis?

Balloon angioplasty/valvuloplasty. - #1 choice

What gradient does the slide give for balloon angioplasty in what severity level PS, and what is its success rate?

• Balloon angioplasty is recommended for (what severity level) -PS with gradients up to ____

mmHg

• _____% success rate of relieving the gradient

• Mild PS with gradients up to 35 mmHg

• >95% success rate in relieving the gradient

What percentage of patients require additional procedures after balloon treatment such as what list 2, and 33% develop significant what lesion afterward

• 21% require additional procedures such as repeat valvuloplasty or RVOT enlargement

• 33% develop significant PI afterward

What happens to RV compliance after relief of pulmonary stenosis?

RV compliance improves

When may Surgery or what replacement be required for pulmonary stenosis? List 2 types of stenosis (like there area)

• Surgery is required for infundibular stenosis and supravalvular stenosis

• Valve replacement may also be required

What is critical pulmonary valve stenosis?

Severe what ? obstruction in which the RV cannot maintain _____saturation above _____% without a what shunt

Severe RV outflow tract obstruction in which the RV cannot maintain oxygen saturation above 90% without a PDA

What direction does blood shunt through the PFO and PDA in critical PV stenosis?

And Blood becomes dependent on what shunt?

• PFO: Right → left

• PDA: Left → right

Blood becomes dependent on PDA

Why does the patient become dependent on the PDA in critical PS ( the PDA helps supply what blood flow?), and what can result?- extra what load on the which Ventricular ? what about biventricular function

The PDA helps supply pulmonary blood flow.

This can cause:

• Extra volume load on the LV

• Poor biventricular function

Why does the LV experience volume overload?

1. In critical pulmonary stenosis, the RV has difficulty pumping blood into the pulmonary artery because the pulmonary valve is severely narrowed.

2. The PDA stays open, allowing blood to travel from the aorta into the pulmonary artery (left-to-right shunting).

3. This additional blood travels through the lungs.

4. The blood returns through the pulmonary veins into the LA, then the LV.

5. The LV receives extra blood, causing LV volume overload.

Simple way to remember: The PDA sends extra blood into the lungs, which eventually returns to the left side of the heart. This increases the amount of blood the LV must handle.

The important distinction is that the PDA helps supply blood to the lungs in critical pulmonary stenosis, but the additional pulmonary blood flow can overload the LV.

What is another name for subpulmonary stenosis?

Infundibular pulmonary stenosis

List the 5 causes of infundibular pulmonary stenosis.

• Discrete ___________obstruction

• Ventricular septal ______

• Sinus of Valsalva ______

• Cardiac ______

• RV _________

• Discrete fibromuscular obstruction

• Ventricular septal aneurysm

• Sinus of Valsalva aneurysm

• Cardiac tumors

• RV hypertrophy

What causes a double-chambered right ventricle?

Anomalous RV muscle bundles

What is a discrete subpulmonary membrane, and where is it located?

A ____with an opening located at or within the ______ostium, usually in the ______portion of the ________

A ring with an opening located at or within the infundibular ostium, usually in the lower portion of the infundibulum

What causes a discrete subpulmonary membrane according to the slide?

Caused by a defect in the ______of the ______

&

Does PS progressive with age?

A defect in the absorption of the infundibulum.

NO PS does not progressive with age!

What is a double-chambered right ventricle?

_______between the RV _____and RV _____caused by abnormal RV what attachments.

Narrowing between the RV inflow and RV outflow caused by abnormal RV muscle-bundle attachments.

What 2 pressure chambers are created in DCRV?

• High-pressure RV chamber

• Low-pressure infundibular chamber

When is DCRV usually detected, and list the 4 associations given.

Usually detected after the first few _____of life.

4 associations given: What the #1, what membrane finding? list 2 syndromes

Usually detected after the first few months of life.

Associated with:

1. Membranous VSD***

2. Subaortic membrane

3. Down syndrome

4. Noonan syndrome

How does DCRV change as the patient ages? The muscle bundles become more what as the patient grows & what is the best view ?

• Obstruction is progressive with age

• Muscle bundles become more prominent as the patient grows

• Best view PSAX at the ventricle level

Where does the VSD usually communicate in DCRV, and how does shunt direction change with severity? in less severe the shunt is what and in severe the shunt may what?

The VSD usually communicates with the high-pressure portion of the RV.

• Less severe → left-to-right

• Severe → shunt may reverse

What may happen if the VSD spontaneously closes in DCRV?

RV dysfunction may occur.

(The VSD acts like the pressure pop -off) Simple way to remember: The VSD closes, but the RV obstruction is still there → continued RV pressure overload → possible RV dysfunction.

Subpulmonary stenosis

How are discrete membranes and DCRV repaired, This repair provides excellent what results list 2? and what happens to RV function afterward with the relief of the what?

• Repair is surgical

• Surgery gives excellent hemodynamic/functional results

• RV function improves after relief of the obstruction

What is the best view for finding subpulmonary obstruction?

Short-axis at the ventricular level.

Where is supravalvular pulmonary stenosis located?

Obstruction _____to the pulmonary valve, and just above the where?

Obstruction Distal to the pulmonary valve, and just above the branch pulmonary arteries.

What 2 forms can supravalvular pulmonary stenosis take?

• Discrete membrane

• Hypoplastic segment

Where along the PA can supravalvular stenosis occur; Visualized as a discrete membrane or a hypoplastic segment; Located where?

• Located Just _____the valve, ____ portion of the PA, or close to the where

• Just below the valve region

• Mid PA

• Near the bifurcation

Etiology

List the 5 syndromes/conditions associated with Supravalvular pulmonary stenosis.

• Williams syndrome

• Noonan syndrome

• Alagille syndrome

• Ehlers-Danlos syndrome

• Rubella

2-3% will have other CHD and cardiovascular anomalies

What previous repairs/procedures may cause supravalvular pulmonary stenosis?

List 2 (first one what can it produce and 2nd what may be associated with?

• Previous repairs can cause it

• Pulmonary artery banding can produce a ridge (done for complete AV - canal defect or single ventricle)

• LeCompte maneuver may be associated with post-stenotic dilation (done when pt has a D-TGA)

List the 4 defects associated with supravalvular pulmonary stenosis.

List 1 congential defect and 3 shunts

• Tetralogy of Fallot

• VSD

• ASD

• PDA

List the 6 management/repair options given for supravalvular pulmonary stenosis.

• _____patch angioplasty for main PA

• Balloon _______

• Intravascular stainless-steel ____

• _______graft of the stenosis

• ______treatment or monitoring or ______Conduit

• Dacron patch angioplasty for main PA

• Balloon angioplasty

• Intravascular stainless-steel stent

• Bypass graft of the stenosis

• Surgical treatment or monitoring

• Rastelli Conduit

Rastelli procedure: includes closing the VSD to the aorta and placing a valved RV to PA conduit for RVOT reconstruction

Dacron patch angioplasty = Widening the narrowed pulmonary artery with a synthetic patch to improve blood flow and reduce the workload on the RV.

What 2 abnormalities can affect the pulmonary artery branches?

• Stenosis

• Hypoplasia

What congenital heart defects are associated with PA branch stenosis? List 3

Conotruncal defects, including examples such as:

• Truncus

• TGA (LeCompte maneuver- causes Lt pulmonary branch artery stenosis)

• Tetralogy of Fallot

What 2 syndromes are strongly associated with PA branch stenosis and this is the same for Unilateral branch stenosis? which one may be progressive? (%?)

1. Alagille syndrome — 76%

2. Williams syndrome — 50%

Williams-associated disease may be progressive

What does Branch PA stenosis do to the RV and PA pressure? List 2 for the RV, and one for the PA

It causes:

• RV pressure overload

• RV hypertrophy

• High PA systolic pressure

What peak PA velocity is associated with branch stenosis,*** and what else may increase PA velocity? List 2

• Peak velocity >1.5 m/s

• Velocity may also increase from:

  • Atrial shunts

  • High cardiac output

Can elevated PA velocity/branch stenosis resolve in infants? if so how long?

&

What is the BEST view for PA Branch stenosis?

Yes. It may resolve within a few months.

(PDA present velocity may be increased b/c of the volume load so make sure its true PS)

BEST VIEW: High PSAX

What may cause unilateral PA branch stenosis, and why can RV pressure remain normal?

• ____tissue may encircle the _____, similar to a ______

• RV pressure may remain normal because the _______ what accommodates the what output

• PDA tissue may encircle the branch, similar to a coarctation

• RV pressure may remain normal because the opposite PA branch accommodates the cardiac output

How does this happen?

1. The PDA (patent ductus arteriosus) connects the aorta to the pulmonary artery during fetal development.

2. The PDA contains tissue that normally constricts after birth to close the ductus.

3. Sometimes this tissue extends into and encircles (wraps around) part of a branch pulmonary artery, usually the left pulmonary artery (LPA).

4. When the PDA tissue contracts, it can also narrow that pulmonary artery branch.

5. This causes branch pulmonary artery stenosis, restricting blood flow to that lung.

Why does your slide say it's similar to coarctation?

Because both involve narrowing of a blood vessel:

• Coarctation of the aorta: Narrowing of the aorta.

• PDA-related branch PA stenosis: Narrowing of a pulmonary artery branch caused by ductal tissue.

Simple way to remember: PDA tissue wraps around a pulmonary artery branch → PDA tissue contracts → Branch PA narrows → Less blood reaches that lung.

Your slide also mentions that RV pressure may remain normal because the opposite pulmonary artery can accommodate more blood flow.

List the 6 things evaluated on echo for pulmonary branch abnormalities.

• Number of PA _____

• Level of ______

• ______through each branch

• Flow rate through the ______ - one maybe what than the other?

• Branch PA _____

• List two of the RV

• and what PV lesion

• Number of PA branches

• Level of obstruction

• Gradient through each branch

• Flow rate through the branches - One maybe higher than the other

• Branch PA size

• RV hypertrophy/function and PI

What 2 windows are used to assess branch PA size?

• High parasternal

• Suprasternal short-axis

What repair options are listed for PA branch stenosis?

• Balloon ______

• Stainless-steel _____

• _____graft of stenosis

• ____or monitoring, or ______Conduit

• Balloon angioplasty

• Stainless-steel stent

• Bypass graft

• Surgery or monitoring

• Rastelli Conduit

What is Pulmonary Atresia with an Intact Ventricular Septum consists of?

• ______pulmonary valve blocks blood flow from the _____into the where

• Ventricular septum is ______

• Pulmonary blood flow depends on a what shunt?

• It is a ________CHD

• Atretic pulmonary valve blocks blood flow from the RVOT into the pulmonary arteries

• Ventricular septum is intact

• Pulmonary blood flow depends on a PDA

• It is a cyanotic CHD (PDA isnt large enough to supply blood flow)

What 2 pathways can provide RV outflow in PA/IVS?

• Coronary artery sinusoids (like a fistula) connecting the coronary circulation to the RV cavity

• Tricuspid regurgitation

How high may RVSP become in PA/IVS?

Up to 200 mmHg.

What direction of flow through the PFO and PDA is necessary for survival in PA/IVS?

• PFO: Right → left

• PDA: Left → right

BOTH necessary for survival as well*

How common is PA/IVS, and when is it usually diagnosed?

what % diagnosed within the first weeks of life

• 85% diagnosed within the first weeks of life - b/c the baby is born cyanotic

What happens without treatment and why, and is PA/IVS usually inherited or associated with maternal tetragons?

It may occasionally occur with what abnormalities?

• Without treatment it can be fatal due to cyanosis

• It may occasionally occur with chromosomal abnormalities

• Not associated with inheritance or maternal tetragons

How does pulmonary-valve morphology relate to RV development in PA/IVS?

• Completely fused PV causing what→ RV may be what - formed

• Very small RV → PV may not have what, and the RVOT may also be what

• Completely fused PV causing membranous atresia → RV may be well formed

• Very small RV → PV may not have developed, and the RVOT may also be atretic

Simple way to remember: The pulmonary valve can be completely blocked, but the RV can still be well developed.

Well-formed RV means the right ventricle has developed relatively normally in size and structure, rather than being severely underdeveloped (hypoplastic).

RV → RVOT → Pulmonary valve (membranous atresia) → Main pulmonary artery

The membrane is at the normal location of the pulmonary valve, completely preventing blood from passing from the RV into the pulmonary artery.

Simple way to remember: Membranous atresia = The PV is fused shut. Muscular atresia = The muscular outflow tract itself is blocked or underdeveloped.

What are the 2 anatomic types of PA/IVS?

• Type 1 — RV hypoplasia

• Type 2 — RV dilation

List the 3 findings of Type 1 – RV Hypoplasia PA/IVS.

• Small but _______what valve

• Hypoplastic ____with coronary artery ____

• About 20% have a what shunt**

• Small but competent tricuspid valve

• Hypoplastic RV with coronary artery fistulae

• About 20% have a secundum ASD**

What relationship exists between tricuspid-valve size and RV size in Type 1 RV hypoplasia in PA/IVS?

TV size correlates with RV size.

The amount of RV hypoplasia depends on how large or small the TV is.

List the 3 findings of Type 2 RV Dilation. PA/IVS.

• Dilated of what List 3?

• what happens with the TV size and what Lesion is found

• what happens with the pulmonary valve

• Dilated RA, SVC, and IVC

• Enlarged tricuspid valve with significant TR

• Membranous pulmonary-valve atresia

Simple way to remember: In Type 2, blood cannot exit through the pulmonary valve, but significant TR allows blood to move back and forth between the RV and RA, contributing to RV dilation.

Pathophysiology in PA/IVS, :

Where does the systemic venous blood crosses? - what shunt and is it usually restricted or unrestricted

and why does cyanosis occur?

• Systemic venous blood crosses the PFO - Usually unrestricted

• Mixing of blood causes cyanosis

Why is PA/IVS called a ductal-dependent lesion?

The _____sends blood to the _____, unless ______collateral arteries are present.

The PDA sends blood to the lungs, unless aortopulmonary collateral arteries are present.

Aortopulmonary collateral arteries are abnormal blood vessels that connect the aorta (systemic circulation) to the pulmonary arteries, allowing blood to reach the lungs through another pathway.

a rare congenital heart defect in which there is an abnormal hole or direct connection between the ascending aorta and the main pulmonary artery.

List the 3 clinical findings of PA/IVS. (what at birth, what is wrong with the heart, and what may occur)

• Cyanosis at birth

• CHF

• Myocardial infarction may occur

List the 5 right-heart/valve findings assessed on echo in PA/IVS.

• Tricuspid valve ____and anatomy

• what TV and PV lesions

• Pulmonary-valve ____if possible

• List 3 things about the RV

• RV and RA ____

• Tricuspid valve size and anatomy

• TR and PI

• Pulmonary-valve gradient if possible

• RV hypertrophy, size, and function

• RV and RA size

List the 4 additional things evaluated on echo in PA/IVS.

• Main and branch PA ____

• Coronary artery _____with color Doppler

• Septal _____

• what two shunt flow direction

• Main and branch PA size

• Coronary artery fistulas with color Doppler

• Septal flattening

• PDA and ASD flow direction

What is the prognosis of PA/IVS without intervention, and what medication keeps the PDA open?

• Prognosis is poor without intervention

• Prostaglandin (PGE) is used to prevent ductal closure

List the 3 reasons on why a Cardiac catheter procedures that may be used for PA/IVS.

• Balloon _______to open/expand the pulmonary valve

• Balloon atrial _______to enlarge the ______ovale

• PDA ____to keep the ductus open

• Balloon valvuloplasty to open/expand the pulmonary valve

• Balloon atrial septostomy to enlarge the foramen ovale

• PDA stent to keep the ductus open

Pulmonary Atresia with and Intact Ventricular Septum:

What is the purpose of a BT shunt?

To allow more blood to pass through the ____and become _______.

To allow more blood to pass through the lungs and become oxygenated.

Simple way to remember: BT shunt = Subclavian artery or innominate artery connected to right pulmonary artery branch using a graft.

Pulmonary Atresia with and Intact Ventricular Septum:

What may be done if the RV is too small, a what palliation with a what list 2 may be performed , and what other major treatment may be considered?

• Single-ventricle palliation with Glenn and Fontan

• Heart transplant may be considered

1. Glenn shunt

Connection: Superior vena cava (SVC) → Right pulmonary artery (RPA)

• The SVC carries deoxygenated blood from the upper body.

• The surgeon connects the SVC directly to the pulmonary artery.

• Blood from the upper body flows directly into the lungs, bypassing the RV.

2. Fontan procedure

Connection: Inferior vena cava (IVC) → Pulmonary arteries

• The IVC carries deoxygenated blood from the lower body.

• The surgeon creates a pathway from the IVC to the pulmonary arteries, usually using a conduit or tunnel.

• Blood from the lower body also bypasses the RV.

What long-term survival is given after appropriate treatment for PA/IVS?

About what % of infants alive at age ___ survive beyond age ____

About 65% of infants alive at age 1 survive beyond age 10.

List the 4 things evaluated after PA/IVS repair.

• Evaluate for what PV lesion and Severity

• Evaluate the TV lesions

• Evaluate ___ outflow track and use what doppler for peak and mean gradients

• Evaluate the single ventricle palliation list the 2

• PI and its severity

• TR

• RVOT with CW Doppler for peak and mean gradients

• Glenn and Fontan circulation

This is when the valve its self is clacified or stenosis what is the wavefrom called? what murmur?

FIXED

Ejection Murmur in systole

This is when there is muscle in the RVH Infundibulm causing obstruction what is this waveform called?

DYNAMIC

(With CW doppler you can see Fixed and PW Doppler usually you can see dynamic / dagger shaped, can show both combintion with each other )