Cardiology Flashcards
Which organs does blood bypass in the fetus and why?
By passes the lungs (because they aren’t developed yet) and the liver (as it is very demanding)
Through which vessel does blood:
a) Travel to the fetus from the placenta?
b) Travel from the placenta to the fetus?
a) Umbilical vein delivers oxygenated blood to the fetus from the placenta
b) Umbilical artery delivers unoxygenated blood from the fetus back to the placenta
What shunts allows blood to bypass the lungs?
What shunt allows blood to bypass the liver?
Lungs: 2
1. Foramen ovale connects the right atrium to the left atrium so allows blood to flow from the right to left atrium, to avoid the lungs
2. Ductus arteriosis - allows blood to travel from the pulmonary trunk (supplied by the right ventricle) to the aorta. Some blood is required to enter the RV so the heart muscle can ‘practice’
Liver: Blood is able to by pass the liver by flowing through the ductus venosus. Blood from the placenta flows through this directly into the vena cava, which then supplies the right atrium.
How common are congenital heart defects?
Which type of heart defect is most common?
Quite common
3-8/1000 babies are affected
What type of shunts (L>R or R>L) present with a ‘blue baby’?
Right to left
Because blood which would go to the lungs to become oxygenated is instead shifted into the systemic circulation without being oxygenated
What type of shunts (L>R or R>L) present with a ‘breathless baby’?
Left to right
If you think about it - by blood building up in the right side of the heart it will then be pushed into the lungs and cause pulmonary oedema due to overload. The baby will not be blue because the blood is going to the lungs to be oxygenated, it’s just that too much blood is going to the lungs which is why problems arise.
What investigations are involved in the diagnosis of congenital heart disease?
ECG (although this is rarely diagnostic)
ECHO
US
What are the 3 main examples of L>R shunts?
Atrial septal defects
Ventricular septal defects
Patent ductus arteriosus
What are the 2 main examples of R>L shunts?
Transposition of the great arteries
Tetralogy of fallot
What is the main cause of outflow obstruction in a sick neonate?
Coarctation of the aorta
What is the main cause of outflow obstruction in a well child (e.g asymptomatic with a murmur)?
Aortic stenosis
Pulmonary stenosis
What do we mean by coarctation of the aorta?
Congenital narrowing of the descending aorta
Normally, when does the foramen ovale close?
When does the ductus arteriosus close?
Foramen ovale usually closes as soon as the baby take’s it’s first breath
Ductus arteriosus usually closes in the first few hours or days
How is a congenital heart defect diagnosed antenatally?
Heart scans are taken at 18-20 weeks
If an abnormality is detected a fetal ECHO is carried out
If a child presents with heart failure in the first week of life what is this likely to be due to?
If it is very severe how is it treated?
Why is this treatment essential?
-
After the first week of life what is the most likely cause of presentation of heart failure?
How do these children typically present?
Left to right shunt
Breathlessness and pulmonary oedema
Presents later as this is when the pulmonary resistance falls
What is Eisenmenger syndrome? How does it develop? When may it present?
What can be turn in terms of treatment?
Eisenmenger syndrome is a syndrome which develops due to a VSD. There is left to right shunting of blood and hence increased pulmonary blood flow. This leads to damage of the pulmonary vessels and there is an increase in the pulmonary vascular resistance in response. If this progresses R>L shunting of blood may develop and child/teenager can present with hypoxia. The only surgical option is a heart-lung transplant, if available, although medication is available to palliate symptoms.
EISENMENGER SYNDROME refers to the problem when there is reversal of the shunt and consequently cyanosis
A resp rate of what is considered to be respiratory distress?
> 60breaths/min
What are 5 different causes of cyanosis of a newborn infant with respiratory distress?
- Congenital heart disease
- Respiratory distress syndrome
- Pulmonary hypertension (failure of pulmonary vascular resistance to fall after birth)
- Sepsis (group B strep and other organisms)
- Inborn error of metabolism
Why are the head and upper limbs NOT affected by coarctation of the aorta?
Where will you see the main effects?
Because the branches to the head and upper limbs emerge before the coarctation so there is no effect on the blood flow to these regions
There will be a weak and delayed femoral pulse and you well see upper body hypertension
What are the hallmarks of an innocent ejection murmur?
-
If cyanosis is duct dependent what is given to maintain ductal patency?
-
What are the 2 main types of ASD?
How do they typically present?
Why may be heard on physical examination?
-
What may be the findings on:
CXR
ECHO
For an ASD?
-
