Embryo 2.2: Cardiac Malformations Flashcards
cyanosantes Vs non-cyanosantes.
En clinique, il est plus pratique de classifier les malformations cardiaques selon qu’elles sont cyanosantes ou non-cyanosantes.
La cyanose indique que la peau est perfusée par du sang désoxygéné, et qu’elle apparaît donc bleutée: une partie du sang aortique provient du coeur
droit. -> communication of right to left.
Les** malformations non-cyanosants résultent d’un shunt gauche-droite**.
Le troisième type d’anomalies est obstructif: coarctations de l’aorte et sténose des valves aortique ou pulmonaire.
Discordance aurioculo-ventriculaire
OD → VG →OD
OG→VD → OG
Clearly no communication between Oxygenated and non Oxygenated > Leads to Death
situs inversus vs isomérismes auriculo-ventriculaires;
situs inversus -> an inversion from left to right. Usually causes no issues. Can be complete (syndromique) or only the heart.
Isomérismes auriculo-ventriculaires -> Both sides of the body are an mirror image of one another
This is problematic due to the neccessary differences between the left and right heart (i.e contraction strength and myocardium thickness
Tetralogie de Fallot
Tetralogie de Fallot: Communications Inter-Ventriculaire
The Inter-Ventriculaire Communications means that the blood from the two ventricles is in contact.
Moreover, the pressure in the RV will increase due to the increased blood flow.
This leads to a hypertrophie of the RV myocardium to account for the increased pressure.
The pulmonary valve has a stanosis due to the excess pressure →this is a good thing because it increases pulmonary resistance to counterbalance the high pressure.
Clearly, this is cyanosante as there is de-oxygenated blood that travels to tissues.
There is no pulmonary hypertension due to the pulmonary stenosis
Pulmonary Hypertension issue
Hypertension kills the endothelial cells exposing fibrin
This leads to coagulation cascade to close the endothelium
This creates a feedback loop because coagulation makes smaller tube which will face higher pressure which causes more damage etc
What is an atresia?
medicine
absence or abnormal narrowing of an opening or passage in the body.
THIS DOES NOT ALLOW FOR ANY PASSAGE OF BLOOD (for example in mitral atresia)
this is different from stenosis
Mitral atresia, aortic stenosis with open arterial canal vs closed.
First off, mitral atresia and aortic stenosis-> These are the same as they both lead to a high pressure in LV which leads to blood flowing into the OD via the foramen oval
If closed CA:
absence de perfusion des artère coronariennes — décès
If open:
Here the blood can travel:
From OG→OD→VD→AP→CA→systemic→retrograde flux to feed coronary arteries
Communication inter-Ventriculaire >5mm
The ability for blood to flow into the RV with lower resistance means that there will be less blood that will be pumped to systemic after each stroke.
Reduced Cardiac Output.
The increased pressure in RV (due to the added oxygenated blood) will lead to an increased pulmonary pressure -> Pulmonary Hypertension and positive feebback
Clearly, there will be no cyanosante as no deoxygenated blood will reach the cells
Pulmonary Artery Stenosis with an open Aortic Canal (light vs severe)
Here, the pulmonary artery has high resistance which means the the blood has less resistance through the Foramen Oval
A light stenosis is not cyanosante, but a severe one yes.
Need the Aortic Canal to be open so that the blood can travel to the lungs for oxygenation, if closed -> death.
Persistance of the Arterial Canal
Normally this canal will be closed after birth.
We said that this closure is highly dependent on pressure. As such, early hypoxia can prevent the closure of aortic canal.
In this case oxygenated blood is “wasted” as it is sent to the lungs.
Moreover, pressure to lungs is increased →pulmonary hypertension
Coartation de l’aorte. Describe what it is and then describe How could this be cynayosante?
This is an issue at the aortic isthme.
In this disease the aortic isthme remains constricted generating a great resistance.
This means that the kidneys receive less pressure, they think this is due to cardiac insuffisance so they trigger the renine-angiotensin pathway which increases blood pressure.
Overall, increased blood pressure Increased RV hypertrophie due to increased resistance
coarctation de l’aorte avec hypertension en amont de la coarctation, et hypotension en
aval, sur hypoperfusion rénale et cascade rénine-angiotensine
cynayosante:
If the aortic canal remains open, blood from the pulmonary artery can enter systemic circulation via the descending aorta (due to low pressure)
