Pulmonary valve dysplasia and risk of Noonan syndrome

Hello;

Here is the complete ECHO evaluation :

Viewed thymus. Left aortic arch. Well developed heart chambers. Normal position of the large vessels. Pulmonary valve dysplasia; pulmonary sheets appear to be reworked and in a dome form. Acceleration of the flow by color Doppler with reverse flow at the level of the pulmonary artery which is dilated. Normal mitral and aortic and tricuspid valves. Aortic arch and normal aortic isthmus. Short-axis normal. Left pulmonary vein and a straight line connecting normally to the left atrium. No evidence of pericardial effusion or cardiomegaly. Normal cardiac dynamics. Regular heartbeat.

NORMAL DOPPLER:
Normal flow: mitral and tricuspid valves, ascending aorta, aortic isthmus, patent ductus arteriosus, ductus venosus, left and right Pulmonary veins. Normal Velocimetry in the umbilical arteries and uterine right.

DOPPLER ABNORMAL:
Maximum speed increased to the level of the pulmonary valve to 0.95 cm/sec.

M MODE:
Trace within normal limits. No hypertrophy.

THEREFORE:
Pulmonary valve dysplasia (of good size) with secondarily dilatation of the main pulmonary artery.

NUMBERS :
Ao Ring : 3 mm
Pulm Ring : 4,3 mm

nuchal translucency normal (at the 19 weeks echography)

PREGNANCY STATUS : 21 Weeks since the ovulation

As for our questions :

- Now that you have all the ECHO in hands, can you tell me if it gets close to a syndrom (ex: Noonan, Williams, Costello) ??

- Does the ECHO still have a discrepancy ?

- In my childhood, there was a suspicion of a valvular problem on me. But there was no significant symptoms to be related further. They were suspicious about the mitral valve. The technology was not the same 30 years ago, obviously. Is it possible to have a link between my case and the one of my pregnancy ?

Hello,

If the valve is really dysplastic and stenotic as mentioned in the report, then the possibility that it may be noonans or costello is there. But that can be confirmed only by genetic testing. What I want to say is that Noonans syndrome or any other with dysplastic valve does not have dilated pulmonary arteries.

The report mentions that the velocity across pulmonary valve is 0.95 which is greater than 95 percentile for a 21 week old fetus. also there is flow reversal in the pulmonary artery. This suggests Pulmonary valve stenosis and regurgitation. Such a picture of stenotic and regurgitant pulmonary valve with dilated pulmonary arteries is seen in absent pulmonary valves but then there should be a VSD and the valve shouldn't be dysplastic.

If the valve is not dysplastic but only stenotic then the pulmonary artery dilatation may be explained. So there is a discrepancy in the report as it does not fit into any fixed pattern.

Maternal cardiac defects increase the risk of fetal cardiac defects but the percentage is very small. Unless you know what exactly was your abnormality at birth, it is not possible to ascertain the fetal risk.

Hope this helps. Please feel free to discuss further.

Best
Dr Vivek Mahajan

Hello;

I have a few more question to be sure to understand correctly our position.

- What is the difference between a dyaplastic valve and a stenotic valve ?

- In litterature, in a pulmonary valve stenosis, there are 10% of valves that are dysplasic. Therefore it exists 2 forms of stenosis (typical and atypical). How can we make the difference between the 2 types ? In our case, the leaflets of the valve seems reworked and in a dome form. Is that the dysplasic characterictic ?

- Why, in a dysplasic pulmonary valve with with a stenosis, there is not supposed to have dilatation post-stenotic while there is dilatation when there is a pulmonary valve stenosis ?

- If the valve is not dysplastic but only stenotic and there is indeed dilatation of the pulmonary artery, does the chances of having a syndrom are reduced ?

- In the case that the valve is stenosed and dysplasic, in your experience, do you know children that are in this situation and do not have a syndrom ?

- Why, in a dysplasic and stenotic valve, there is not supposed to have post-stenotic dilatation ?

Thank you

Hello,

A stenotic pulmonary valve may be dysplastic or non dysplastic. Here is how you differentiate them structurally.

The most common pathology is a dome-shaped pulmonary valve. The fused leaflets of the pulmonary valve protrude from their attachment into the pulmonary artery as a conical, windsock-like structure. The size of the pulmonary valve orifice varies from a pinhole to several millimeters. The orifice is most usually central but can be eccentric. Raphae, presumably fused commissures of the valve, extend from the stenotic orifice to a variable distance down into the base of the dome-shaped valve. The number of the raphe may vary from 0-7. Relatively uncommon variants are unicommissural, bicuspid, and tricuspid valves. The valve annulus is abnormal in most cases, and the fibrous back bone is partially or completely lacking; therefore, a true annulus may not be present.

Hypoplasia of the pulmonary valve ring and dysplastic pulmonary valves may be present in a few of patients. Pulmonary valve dysplasia is characterized by thickened, nodular, and redundant valvular leaflets with minimal or no commissural fusion; hypoplasia of the valve ring; and lack of poststenotic dilatation of the pulmonary artery.The obstruction is mainly related to thickened, myxomatous, immobile pulmonary valve cusps and hypoplasia of the valve ring.

The main pulmonary artery is dilated in almost all cases. This dilatation is independent of the severity of the pulmonary valve obstruction and presumably related to a high-velocity jet across the stenotic valve.As noted above, such poststenotic dilatation is remarkably absent in patients with dysplastic pulmonary valves, Why it is absentI dont know!!
You shall find more answers to your questions on page no 397 and 396 of this book
http://books.google.co.in/books?id=vxD6L_S93WsC&pg=PA397&lpg=PA397&dq=dysplastic+pulmonary+valve+definition&source=bl&ots=uTVOjFVKEq&sig=E_4KktH81QoM7URl4KCTc-aXguI&hl=en&sa=X&ei=HWQGUojMPMOzrAeg6YCoBA&ved=0CHAQ6AEwCDgK#v=onepage&q&f=false

Now your echo report says Pulmonary valve is dome shaped and still he calls it dysplastic.. Discrepancy!!

I do not understand what he means by the term reworked. There is no explanation for why there is no post stenotic dilatation in dysplastic stenosis of pulmonary valve.. It needs further research!!

If the valve is not dysplastic but only stenotic and there is indeed dilatation of the pulmonary artery, does the chances of having a syndrome are reduced ?.. yes. But this condition is associated usually with other cardiac abnormality. Fortunately your baby doesn't show any other abnormality if the echo report is to be trusted.

In the case that the valve is stenosed and dysplasic, in your experience, do you know children that are in this situation and do not have a syndrome ?.. The chances are very high that such a child will have some syndrome or systemic abnormality. My experience.. have not seen any nonsyndromic dysplastic pulmonary valve.

Now your echo report also says that the fetus is having abnormal doppler velocity across pul valve.. SO there is stenosis.. and still there is no effect on the Right ventricle.. Discrepancy!

Also it says there is flow reversal in pulmonary artery.. Pulmonary regurgitation with pulmonary stenosis is not a feature of the condition that we are discussing. It is seen in absent pulmonary valve with intact IVS.. so that is a discrepancy.

Hope this helps, please feel free to discuss further.

Regards,
Dr Vivek Mahajan

Hello again;

Some things doesn't seem to be clear for me. Here are my interrogations :

- I have some difficulty to understand the part that you explain the annulus/ring. The cardiologist said to me that the ring was of good size, and the proportion with the AoRing was good also. A good size ring is more prone to which case ?

- Since the cardiologist said us that the ring was normal, does that mean that there is no hypoplasia ?

- Also, is it possible to do not have hypoplasia and to have dysplasia ?

- If there is only a stenosis with a dilatation, you said that the chances of syndrome are reduced. Of how much % the chances of syndrome are reduced, by your practice ?

- Does having other cardiac anomalies (other than the stenosis and the dilatation) is a factor to reduce the chances of syndrome compared to a case where there is only a stenosis and a dialtation ?

- You say that the valves need to be absent to have regurgitation. The cardiologist said to us that there is reverse flow (a.k.a. Regurgitaion) and that the valves are present. Is it possible to have regurgitation when the valves are present ?

- And with the regurgitation just talked, is it possible that this regurgitation create the dilalation of the pulmonar artery ?

Thank you for your answers. I hope to have a better understanding after all of these discussions.

Hello,

A good sized ring means no hypoplasia. A dysplastic valve is most frequently associated with a small annulus. Whereas barring critical PS, if the valve is non dysplastic the annulus is usually not hypoplastic. the findings in your case dont suggest critical PS. I cannot say that it is impossible to have a normal annulus with dysplasia but dysplasia is associated very commonly with hypoplasia of annulus. in my practice i havent seen noonans syndrome having dilated pulmonary arteries.

Associated cardiac abnormalities may be absent even in noonans syndrome. their absence does not help differentiate if the baby is having dysplatic or non dysplastic type. these associated abnormalities can be present in both, though they are of different types in both. regurgitation can cause dilatation. I cannot recollect any condition in a fetus which leads to significant pulmonary regurgitation except may be a flail pulmonary valve. but i think its very rare and would be ficked up on echo.

Regards
Dr Vivek Mahajan


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In-house Physician's Comment -
Your consult is now complete with 3 follow-up questions. Thank you.