Cardiac conditions Flashcards
What vessel caries blood from the placenta to the fetus?
Umbilical vein
What vessel carries blood from the fetus to the placenta?
Umbilical artery
What are the three shunts that are specific to foetal life and what do they do?
Ductus venosus (Connects the umbilical vein to the IVC) Foramen Ovale (Opening in the atrial septum connecting the RA to the LA) Ductus arteriousis (Connects the pulmonary bifurcation to the descending aorta)
What is the purpose of the ductus venosus?
It connects the umbilical vein to the IVC. This is because the nutrients are coming straight from the placenta and don’t need to be processed in the liver. The ductus venosus allows the liver to be bypasses and blood to directly enter the circulation.
What is the purpose of the foramen ovale?
It allows blood to flow from the right to left atrium. This means that all the best oxygenated blood can enter the left atrium, then the left ventricle and then the aorta, carotids etc
What is the purpose of the ductus arteriosus?
Only 7% of the RV output goes to the lungs (the lungs do not oxygenate the blood in fetal life!) The rest goes via the ductus arteriosus to join the descending aorta.
About what % of the adult population have a patent foramen ovale?
35%
What is persistent pulmonary hypertension of the newborn?
The lung vascular resistance fails to fall due to a failure of closure of the foramen ovale and/or the ductus arteriosis. This menas that the baby is blue and that there is a large difference between pre and post ductal oxygen saturation.
What maintains the patency of the ductus arterious in the fetus?
Prostoglandin E2
Give examples of mild congenital heart disease
Small VSD
Small ASD
Small PFO
Small PDA
Describe transposition of the great vessels
A group of congenital heart disease where the great vessels are in the wrong place. For example in transposition of the great arteries the aorta and the pulmonary artery are switches meaning that deoxigenated blood gets pumped around the body and there is no blood flowing to the lungs to become oxygenated (hence the cyanosis)
How does transposition of the great vessels tend to present?
Presents at the time of duct closure (between 2 and 7 days)
Severe Cyanosis, tachypnoea, Absent pulses
Acidosis
What is the initial managment of a baby who is cyanotic due to transposition of the great vessels?
ABC
Prostoglandin E2 (opens duct)
Transfer to cardiac surgical unit
What is hypoplastic left heart syndrome and how does it present?
The left side of the heart in severely underdeveloped. This results in cyanosis at the time of duct closure
How does a large ventricular septal defect present?
A murmur develops as the pulmonary pressure drops over the first few weeks. This leads to increased pulmonary circulation and congestive cardiac failure.
List the common acyanotic heart defects
Patent ductus arteriosus Coarctation of the aorta Ebsteins anomaly Atrial Septal defect Ventricular Septal defect
What is coarctation of the aorta and how does it present?
The aorta is narrowed at the area where the ductus arteriosus inserts. There is sometimes no symptoms and children present when they are older with failure to thrive. They are more common in girls with turners syndrome.
List the common cyanotic heart defects?
Tetralogy of Fallot Transposition of the great arteries Tricuspid atresia Pulmonary atresia Hypoplastic left heart syndrome
What is tetralogy of fallot?
Cyanotic heart defect that included four defects:
- Pulmonary stenosis (narrowing of the exit from the right ventricle)
- Ventricular septal defect
- Right ventricular hypertrophy
- Overriding aorta (blood from both ventricles can enter the aorta)
What is ebstein’s anomaly?
Congenital heart defect in which the septal and posterior leaflets of the tricuspid valve are displaced downwards towards the apex of the right ventricle. This means that the right atria is very large and the right ventricle is very small.,
What medication increases the risk of an ebsteins anomaly?
Lithium
A baby is found to have a constant “machine like murmur’ and a heaving apex beat found on their newborn baby check.
Patent ductus arteriosus
What medication can be given to close a patent ductus arteriosis?
Indomethacin
What kind of murmur do you get in tetralogy of fallot and why?
Ejection systolic murmum due to pulmonary stenosis
