CVS - Transposition of Great Arteries (TGA) Flashcards
1
Q
Aetiology of TGA.
A
Failure of Aorticopulmonary Septum to spiral during septation.
2
Q
Risk Factor of TGA (1).
A
Diabetic Mother.
3
Q
Associated Features of TGA (3).
A
- VSD.
- Aortic Coarctation.
- Pulmonary Stenosis.
4
Q
Clinical Features of TGA (4).
A
- Cyanosis.
- Tachypnoea.
- Loud Single S2.
- Prominent Right Ventricular Impulse.
5
Q
Pathophysiology of TGA (4).
A
- Aorta leaves RV & Pulmonary Trunk leaves LV (wrong way around).
- 2 Separate circulations don’t mix (Right = Systemic; Left = Pulmonary).
- During Pregnancy = normal development of foetus with gas and nutrient exchange in placenta.
- After birth = immediate life-threatening due to no connection = cyanosis.
6
Q
Investigations of TGA (2).
A
- CXR - Egg-on-Side/String Appearance.
2. Diagnosed often during antenatal Ultrasound scans.
7
Q
Management of TGA (4).
A
- Immediate survival depends on a shunt between the two circulations e.g. PDA, ASD or VSD (provides a few weeks of life before development of symptoms and respiratory distress).
- Maintain Ductus Arteriosus with Prostaglandins.
- Balloon Septostomy (insert catheter into Foramen Ovale via Umbilicus to inflate balloon and create a large ASD).
- Definitive = Surgical correction (Open Heart Surgery) : cardiopulmonary bypass machine is used to perform an ‘arterial switch’. Correct any co-existing defects.