Session 3 - Congenital Heart Disease Flashcards
What is an atrial septal defect?
A heart defect in which there is an opening of the septum between the two atria
What usually causes an atrial septal defect? And what does it usually result in?
Failure of the Foramen Ovale to close
Left to right shunt due to higher pressures in the LA
What is a Patent Foramen Ovale?
Not a true ASD, generally clinically silent
This is because of higher left atrial pressure closing the flap
What is a ventricular septal defect?
An opening of the Interventricular septum, most commonly at the Membraneous portion.
Left to right shunt
What is a Patent Ductus Arteriosus?
The vessel that in the foetus shunts blood from the PA -> Aorta.
A PDA is when this shunt persists after birth, blood will flow from the Aorta -> PA
How can a Patent Ductus Arteriosus cause damage in later life?
Chronic L->R shunting can result to vascular remodelling of the pulmonary circulation and increase pulmonary resistance
If resistance > systemic circulation shunt will reverse direction (Eisenmenger Syndrome)
What is coarctation of the aorta?
Narrowing of the aortic lumen in the region of the ligamentum arteriosum
Why are the head and upper limbs not effected in aortic coarctation?
The branches that supply these branch off the aorta proximal tot he ligamentum arteriosum
What are the four heart defects in Tetralogy of Fallot?
- Ventricular Septal Defect
- Overriding aorta
- Pulmonary Stenosis
- RV Hypertrophy
Describe the events that lead to Tetralogy of Fallot becoming cyanotic
- Pulmonary stenosis results in RV Hypertrophy
- Increase in pressure in RHS + VSD + overriding aorta = R->L shunt
- This mixes the blood causing cyanosis
What is a tricuspid atresia?
- lack of development of the tricuspid valve
- no inlet to the RV
- Must be a complete R->L shunt of all blood returning to RA (ASD or PFO) + a VSD or PDA to allow blood to flow to the lungs
What occurs in Transposition of Great Arteries?
The two circulations from the heart become unconnected. The RV -> Aorta and the LV -> PT
This is not compatible with life after birth unless a shunt exists or is created until surgery can take place
The ductus Arteriosus can be maintained +/or an ASD formed
What is a Hypoplastic left heart?
The LV and ascending aorta fail to develop properly
PFO + ASD also present + blood supply to systemic circulation is via a PDA
Without surgery is lethal
What is an acyanotic heart defect?
A heart defect not resulting in a decreasing the concentration of oxygen in blood
