Flashcards in Congential Heart Disease Deck (92)
What are the haemodynamic effects of ASD’s?
Increased pulmonary blood flow
What is the result of an increased pulmonary blood flow?
Right ventricular volume overload, leading to eventual right heart failure
Is a patent foramen ovale a true ASD?
What is the prevalence of a patent foramen ovale?
May be present in ~20% of the population
What is the result of a patent foramen ovale?
Generally, clinically silent
Why is a patent foramen ovale generally clinically silent?
Since higher left atrial pressure causes functional closure of the flap valve
How can a patent forman ovale cause problems?
It may be a route by which venous embolism reaches the systemic circulation, if the pressure on the right side of the heart increases even transiently
What is it called when a patent foreman ovale causes a venous embolism in the systemic circulation?
A paradoxical embolism
What is a ventricular septum defect?
An opening in the interventricular septum
Where can a ventricular septum defect occur?
At any point
Where does a ventricular septum defect most commonly occur?
In the membranous portion of the septum
What are the haemodynamic effects of a ventricular septum defect?
Left to right shunt
Why does a ventricular septum defect cause a left to right shunt?
Because the left ventricular pressure is much higher than the right
What is the result of the left to right shunt?
Left ventricular volume overload, causing pulmonary venous congestion
What does pulmonary venous congestion eventually lead to?
What is the ductus arteriosus?
A vessel that exists in the foetus to shunt blood from pulmonary artery to aorta before lungs are functional
What should happen to the ductus arteriosus shortly after birth?
It should close
Why does the ductus arteriosus close shortly after birth?
As pressure in the pulmonary artery drops following perfusion of lungs
What does failure of the ductus arteriosus to close cause?
Patent ductus arteriosus
In what direction would blood flow through the ductus arteriosus after birth?
From the aorta to the pulmonary artery
Why would blood flow from the aorta to the pulmonary artery if the ductus arteriosus remained open after birth?
Because its going from a high pressure to a low pressure
What is heard when the ductus arteriosus is patent?
A mechanical murmur is heard constantly throughout systole/diastole
Why can a mechanical murmur be heard when there is a patent ductus arteriosus?
Because pressure in the aorta is always greater than in the pulmonary artery
Does left to right shunting of blood cause cyanosis?
What does the extend of the problem caused by a patent ductus arteriosus depend on?
The degree of shunting
What does chronic left to right shunting lead to?
Vascular remodelling of pulmonary circulation, and an increase in pulmonary resistance
What happens if the pulmonary circulation increases beyond that of the systemic circulation due to a patent ductus arteriosus?
The shunt will reverse direction
What is it called when the shunt caused by a patent ductus arteriosus reverses direction?
What is coarction of the aorta?
Narrowing of the aortic lumen in the region of the liganentum arteriosum