Cardiology Flashcards
(151 cards)
What is Eisenmenger syndrome?
Eisenmenger syndrome describes the reversal of a left-to-right shunt (patent ductus arteriosus, atrial septal defect, or ventricular septal defect) to a right-to-left shunt
What are the three fetal circulatory shunts?
Ductus venosus
Foramen ovale
Ductus arteriosus
Role of the ductus venosus in fetal circulation?
Connects the umbilical vein to the inferior vena cava
Allows blood to bypass the liver
Which fetal shunt connects the umbilical vein to the inferior vena cava?
Ductus venosus
Which fetal shunt allows blood to bypass the liver?
Ductus venosus
Role of the ductus arteriosus in fetal circulation?
Connects the pulmonary artery with the aorta
Allows blood to bypass the pulmonary circulation
Which fetal shunt connects the pulmonary artery and the aorta?
The ductus arteriosus
Which fetal shunt allows blood to bypass the pulmonary circulation?
Ductus arteriosus
Role of the foramen ovale in fetal circulation?
Connects the right atrium with the left atrium and allows blood to bypass the right ventricle and pulmonary circulation
Which fetal shunt connects the right atrium and left atrium?
Foramen ovale
Which fetal shunt allows blood to bypass the right ventricle and pulmonary circulation?
Foramen ovale
Why do the 3 fetal shunts exist?
So that blood can travel to the placenta and back
Blood does not need to pass through the pulmonary circulation as the fetal lungs are not fully developed of functional
Fetal blood needs to go via the placenta to collect oxygen and nutrients and dispose of waste products via the mother (lactate, CO2)
How does the foramen ovale become the fossa ovalis?
Baby takes first breaths - alveoli expand - DECREASE IN PULMONARY VASCULAR RESISTANCE
DECREASE IN PULMONARY VASCULAR RESISTANCE causes pressure to fall in the right atrium and the LEFT ATRIAL PRESSURE BECOMES GREATER THAN THE RIGHT ATRIAL PRESSURE
the change in pressure squshes the septum casuing the foramen ovale to close (similar to a closed valve with nothing flowing through it)
This then gets sealed shut structurally after a few weeks and becomes the fossa ovalis.
What does the foramen ovale become after birth?
The fossa ovalis
How does the ductus arteriosus become the ligamentum arteriosum?
Increased blood oxygenation after baby takes its first breath causes a drop in circulating prostaglandins.
Prostaglandins are required to keep the ductus arteriosus open.
This causes closure of the ductus arteriosus, which becomes the ligamentum arteriosum.
What does the ductus arteriosus become after birth?
Ligamentum arteriosum
How does the ductus venosus become the ligamentum venosum?
Immediately after birth the ductus venosus stops function as umbilical cord is clamed and there is no flow in the umbilical veins
The ductus venosus structurally closes a few days later and becomes the ligamentum venosum.
What does the ductus venosum become after birth?
Ligamentum venosum
Which fetal shunt was the ligamentum venosum?
Ductus venosus
Which fetal shunt was the ligamentum arteriosum?
Ductus arteriosus
Which fetal shunt was the fossa ovalis?
Foramen ovale
How does fetal circulation change at birth?
- Neonate takes first breaths - alveoli expand - decrease in in pulmonary vascular resistance leads to a fall in pressure in the right atrium, which squashed the atrial septum causing functional closure of the foramen ovale.
After a few weeks foramen ovale sealed structually becoming the ossa ovalis
- Increased blood oxygenation causes a drop in ciculating prostaglandins, causing closure of the ductus arteriosus (which requires prostaglandins to keep it open)
Closure of the ductus ateriosus occurs and it becomes the ligamentum arteriosum
- Umbilical cord clamped so flow ceases in umbilical veins, therefore ductus veonsus stops functioning
A few days later the ductus venosus closes structurally and becomes the ligamentum venosum
What are innocent murmurs?
'’Flow murmurs’’
Very common in children
Causes by fast blood flow through various areas of the heart during systole
Clear innocent murmurs with no concerning features may not require any investigations. Features that would prompt further investigations and referral to a paediatric cardiologist would include what?
Murmur louder than 2/6
Diastolic murmurs
Murmurs which are louder on standing
Other symptoms: failure to thrive, feeding difficulty, cyanosis, SOB