Congenital Heart Disease Flashcards
What are the two types of atrial septal defect, and which is most common?
Ostium secondum (most common) Ostium primum
What are the clinical features of a small ventricular-septal defect?
Usually asymptomatic
Pansystolic murmur loudest at the lower left sternal edge is picked up, usually on routine childhood examination
Which chemical keeps the ductus arteriosus open in the foetus, and where is it produced?
Prostaglandin E2
Produced in the ductal epithelium
Are septal defects cyanotic or acyanotic?
Acyanotic - there is a left to right shunt
What are the possible symptoms of a patent ductus arteriosus?
- May be none
- Apnoea
- Bradycardia
- Increased oxygen requirement
- Difficulty weaning from artificial ventilation
- Bounding pulse
- Continuous ‘machinery murmur’
What is the management for symptomatic patent ductus arteriosus?
Physiological closure with prostaglandin synthetase inhibitor e.g. indomethacin or ibuprofen
Surgical ligation if medical management fails
Which is more common, ASD or VSD?
VSD
Which vessel carries oxygenated blood from the placenta to the foetus?
Umbilical vein
What does the ductus venosus do?
Connects the umbilical vein to the inferior vena cava, allowing oxygenated blood from the placenta to bypass the liver
Which opening in the foetal circulation connects the right atrium to the left atrium?
Foramen ovale
Which opening in the foetal circulation connect the pulmonary arteries to the aorta?
Ductus arteriosus
What are the heart sounds like in an atrial septal defect?
Wide, fixed splitting of the second heart sound (‘lub splat…lub splat…lub splat’)
What are the heart sounds like in a patent ductus arteriosus?
‘Machinery murmur’ i.e. continuous murmur, loudest in the pulmonary region and radiating to the back
What are the features of a benign murmur?
Soft, systolic murmur at the left sternal edge
No radiation to carotids
No bruits
May be associated with a fever, and will resolve when the fever settles
How might a child with a large ventricular septal defect present?
Signs of heart failure at 4-6 weeks
Breathlessness / sweating whilst feeding or crying
Recurrent chest infections
Faltering growth
What are the clinical SIGNS of a large VSD?
Pan systolic murmur may be absent or soft due to the large size of the defect
What is Eisenmenger’s phenomenon?
Reversal of a left to right shunt e.g. in patient with a VSD where the blood is being forced from left to right out of the pulmonary arteries, the continued force will eventually cause the pulmonary artery to become stenosed and thus increase it’s resistance. Because blood moves via the route of least resistance, the shunt will reverse and blood will go from right to left out of the aorta. As the blood is deoxygenated, this causes cyanosis.
How might an atrial septal defect present?
Asymptomatic until an arrhythmia in the patient’s 30s or 40s (e.g. SVT and AF). Heart sounds: ‘wide, fixed, splitting of the 2nd heart sound’
What are the components of Tetralogy of Fallot?
Pulmonary stenosis Right ventricular hypertrophy Overriding aorta VSD (Also remember 'ejection systolic murmur')
What is the treatment for Tetralogy of Fallot?
Blalock-Taussig Shunt - performed between 1 and 5 years of age
What signs might you get on cardiovascular examination of an infant and a child with coarctation of the aorta?
Both = Systolic murmur
Infants = Absent femoral pulses
Older children = Radio-femoral delay
Which type of shunt is cyanotic - a right-to-left, or a left-to-right?
Right to left shunts are cyanotic
Give 2 examples of cyanotic congenital heart defects
Tetralogy of Fallot
Transposition of the Great Arteries
What is the arrangement of arteries in transposition of the great arteries?
The aorta comes off the right ventricle, the pulmonary arteries come off the left ventricle
What is the presentation of transposition of the great arteries?
Cyanosis, especially from Day 2 of life when the ductus arteriosus has closed
Explain the defect in transposition of the great arteries
The great arteries are switched around, such that the aorta comes off the right ventricle and the pulmonary arteries come off the left ventricle. This means deoxygenated blood is carried round the body, and oxygenated blood is transported to the lungs. This is not compatible with life unless there is a shunt which allows mixing of the 2 circulations e.g. a VSD or ASD. It presents with cyanosis, especially after the ductus arteriosus closes because this maintains mixing of blood until that point.
What is the treatment for transposition of the great arteries?
Prostaglandin infusion to keep the ductus arteriosus open
Septostomy creates a shunt between the atria to maintain mixing of blood
Arterial ‘switching’ operation
If an ASD is detected in childhood, should it be corrected?
Yes - It should be corrected before significant pulmonary hypertension and need for lung transplantation occurs
