CV125 Congenital Heart Disease Flashcards
Stenosis
narrowing of valve or artery
coarctation
narrowing of blood vessels (used specifically when talking about arteries)
atresia
complete blockage
regurgitation
valve leakage
When does the fall in Pulmonary Vascular Resistance occur in babies?
1) the first 48 hrs of life
2) full drop occurs by 2 months of age
what are the most common types of Left to Right Shunt?
1) Atrial septal defect (ASD)
2) ventricular septal defect (VSD)
3) patent ductus arteriosus
4) AV Canal defect
Describe how blood flows in an ASD
Secundum (middle part of the atrial wall) is missing. RA blood flows into the RV and into the lungs but once blood gets to the LA, the blood goes back into the RA because of the higher pressure in the LA. The lungs see more blood than they should.
What is a VSD?
A hole in the ventricular septum
what happens to SVR when the placenta is disconnected?
increase in SVR
what triggers/promotes the beginning of spontaneous closure of ductus arteriosus?
increased arterial oxygen level during first days of life which causes constriction of the smooth walls of the ductus arteriosus (it squeezes tight and closes). contraction is followed by permanent fibrosis. This is usually complete by Day 3. Permanent closure usually happens first 2-3 days of life.
what causes the closure of the foramen ovale?
increased LA pressure due to systemic vascular resistance increase.
How long does it take for the foramen ovale to close?
between 4-6 months of life
What takes longer to close, foramen ovale or ductus arteriosus?
foramen ovale
How long does it take for the majority of PVR to fall in a newborn?
This occurs in the first 48 hrs but a full drop occurs by 2 months of age.
What are factors that alter normal heart transition in the newborn?
1) prematurity because there is immature smooth muscle in ductus arteriosus making it difficult to shut
2) neonatal stress such as hypoxia, acidosis, sepsis which cause a delay in PVR drop
What are the 3 most common presenting features that alert people of congenital heart disease?
1) murmur
2) congestive heart failure
3) cyanosis
What are the 2 large groups of heart defects?
acyanotic and cyanotic
What is the difference between acyanotic and cyanotic heart defects?
Acyanotic are more common. Do not make the babies overall oxygen saturation impaired
What are the 2 types of cyanotic heart defects?
1) left to right shunt
2) obstruction
How to fix ASDs?
usually fix later in life, at 3-4 years of age to see if it fixes itself. Can detect because hear a murmur. cover hole
Describe blood flow in VSD
Blood from LV moves into the RV because of higher pressure
What is the most common congenital heart defect?
VSD
What is a patent ductus arteriosus?
when the ductus arteriosus fails to close
Describe blood flow in PDA
Because ductus arteriosus is not closed, blood from the aorta (due to high pressure) flows back into the pulmonary artery and into the lungs. Therefore, more blood goes to the lung that should.
What is An AV Canal defect?
Where there is a hole in both the atrial septum and the ventricular septum where there is no tricuspid and bicuspid valve (just an entire large one)
What congenital heart defect is found almost exclusively in children with Down’s syndrome?
AV canal defect
What is Eisenmenger syndrome ?
When a child has a left to right hole that does not get repaired, this leads to chronic flow through hole which then leads to irreversible pulmonary hypertension and hypertrophy. This leads to progressive cyanosis and death because pressure in the right side becomes higher than in the left (blue blood travels into systemic circulation)
What are some cardinal signs of cardiac failure in childhood ?
1) tachycardia
2) tachypnea (breathing faster than they should)
3) hepatomegaly (liver is larger - congested and swollen) due to venous pressure back-up
4) failure to thrive (grows normally by doesn’t gain weight properly)
What are the 2 types of acyanotic lesions with obstruction?
No shunting, just blockage
1) aortic stenosis (narrowing of the valve
2) coarctation of the aorta (narrowing of the aorta)
What is Aortic Stenosis?
Valve is abnormal. Something is preventing the leaflets from opening properly. Turbulence through the valve presents as a murmur.
What is Coarctation of the aorta?
A tightness and pinching in of the aorta. Allowing adequate blood flow to the head but not enough to the lower areas (legs etc).
What is iterated Aortic Arch?
An extreme form of coarctation of the aorta in which the aortic arch is completely detached from the descending aorta. If the ductus arteriosus is open then the baby will get blue blood flow to the rest of the body. As soon as it closes, the baby will go into severe shock
What is a hyperoxic test?
administration of 100% oxygen with failure to raise the partial pressure of oxygen above 150 mmHg.
