Transposition of Great Arteries Flashcards
What is transposition of the great vessels?
A group of congenital heart defects involving an abnormal spatial arrangement of any of the great vessels
What are the great vessels?
- Superior and inferior vena cavae
- Pulnonary artery
- Pulmonary veins
- Aorta
What is the name of the sub-group of conditions only involving the aorta and pulmonary artery?
Transposition of the Great Arteries
What happens in transposition of the great arteries?
- The aorta is connected to the right ventricle
- The pulmonary artery is connected to the left ventricle
What does transposition of the great arteries result in?
Two parallel circulations
What does the two parallel circulations result in?
Oxygnetated blood is returned to the lungs and de-oxygenated blood is returned to the body
What is required for transposition of the great arteries to be compatible with life?
Mixing of blood
What are the risk factors for transposition of the great arteries?
- Pre-existing DM of pregnant mother
- History of rubella or other viral illness during pregnancy
- Drinking alcohol during pregnancy
What is the most prominent symptom of transposition of the great arteries?
Cyanosis - may be profound and life-threatening
When is presentation of transposition of the great arteries most common?
On day 2 of life
Why is presentation of transposition of the great arteries most common on day 2?
This is usually the point by which the ductus arteriosus closes and mixing of saturated and desaturated blood stops
Is there a murmur in transposition of the great arteries?
Not usually but there can be a systolic murmur
How does the second heart sound sound?
Loud and single
What is seen on a CXR in transposition of the great arteries?
- Narrow upper mediastinum
- ‘Egg on side’ appearance of cardiac shadow
- Increased pulmonary vascular markings
How does the ECG appear in transposition of the great arteries?
Normal
Why is an echo essential in investigation of transposition of the great arteries?
To demonstrate abnormal arterial connections and associated abnormalities
What are the differentials for transposition of the great arteries?
- Tricuspid or pulmonary atresia
- Tetralogy of Fallot
What is the key to managing the sick cyanosed neonate?
Improve mixing of blood
What is mandatory to achieve mixing in patients with transposition of the great arteries?
Maintaining the patency of the ductus arteriosus with prostaglandin infusion
What procedure can often be life saving in transposition of the great arteries?
Balloon atrial septostomy
What happens in a balloon atrial septostomy?
A catheter with a balloon at its tip is passed through the umbilical or femoral vein and through the right atrium and foramen ovaleand inflated in the left atrium before being pulled back through the foramen ovale
What effect does balloon atrial septostomy have?
The balloon tears the atrial septum rendering the foramen ovale patent and aloows mixing of blood
What do all patients with transposition of the great arteries require eventually?
Surgical correction
What is the usual procedure in the neonatal period?
Arterial switch procedure
What occurs in the arterial switch procedure?
The pulmonary artery and aorta are transected above the arterial valves and switched over
What also has to happen in an arterial switch procedure?
The coronary arteries have to be switched to the new aorta
What are the potential complications of transposition of the great arteries?
- Hypoxia
- Heart failure
- Lung damage
