Cyanotic congenital heart disease Flashcards
What are the causes of cyanosis in CHD?
decreased pulmonary flow with a right to left shunt e.g. tetralogy of fallot
abnormal mixing or systemic and pulmonary venous return e.g. transposition of the great arteries
What is tetralogy of fallot?
a large VSD
overriding aorta with respect to the ventricular septum
subpulmonary stenosis causing RV outflow obstruction
RVH
What are the symptoms of tetralogy of fallot?
most diagnosed antenatally
murmur in first month
cyanosis at this stage may not be obvious
hypercyanotic spells:
rapid increase in cyanosis, characterised by inconsollable crying due to hypoxia
breathlessness
pallor
What are the signs of tetralogy of fallot?
clubbing
loud harsh ejection systolic murmur- left sternal edge
increasing RV outflow obstruction leads to the murmur shortening and cyanosis increasing
Tetralogy of fallot investigations
CXR:
usually normal
if older child: small heart, uptilted apex (boot shaped), right sided arch, decreased pulmonary vascular markings
ECG:
normal at birth
RVH when older
Echo
management of tetralogy of fallot
initially medical
surgical intervention ~ 6 months: close VSD, relieve R sided obstruction with an artificial patch
shunt in those who are severely cyanosed: between subclavian artery and pulmonary artery
what is transposition of the great arteries?
when the aorta is connected to the right ventricle and the pulmonary artery is connected to the left ventricle
this leads to two parallel circulations but some anomalies e.g. septal defects can mix blood
what are the symptoms of transposed arteries?
cyanosis- can be profound and life threatening, usually occurs when ductus arteriosus closes
what are the physical signs of transposed arteries?
cyanosis
finger clubbing (rare)
usually no murmur, but can ave systolic murmur from increased flow from outflow tract
how are transposed arteries managed?
key is to mix saturated and unsaturated blood
maintain patency of ductus arteriosus with a prostaglandin infusion
balloon atrial septostomy, allows mixing of blood between atria
arterial switch procedure: cut just above the arterial valves, the coronary arteries also have to be transferred to the new aorta
what are the types of duct dependent lesions
duct dependent:
- TOF
- tricuspid atresia or ebsteins abnormality
- pulmonic atresia or stenosis
- Hypoplastic left heart syndrome
What is tricuspid atresia?
only left ventricle is effectively working, the right is small and non functional
clinical features of tricuspid atresia
cyanosis, mixing of systemic and pulmonary venous return in the left atrium
tricuspid atresia management
a shunt inserted between the subclavian and pulmonary artery (blalock- taussig shunt) to help with cyanosis
palliation occurs as there is only one effective ventricle: glenn operation which connects the superior vena cava to the pulmonay artery
