Transposition of the great Arteries Flashcards
Define transposition of the great arteries
Cyanotic congenital cardiac defect when the origins of the aorta and pulmonary artery are reversed or transposed.
What is the key epidemiology of transposition of the great arteries (TGA)?
3% of all congenital heart defects
1 in 4,000 live births
Slightly more common in males
Often defected during foetal ultrasound screening or shortly after birth
What is the underlying process in TGA?
Normal heart development involves spiralling of the aortopulmonary septum
In TGA spiralling fails to occur - aorta arises from right ventricle and PA from the left ventricle
Results in two parallel separate circulations
Only compatible with life whilst the PDA or any septal defects allow mixing of blood.
What are some risk factors for TGA?
Maternal diabetes mellitus
Rubella infection during pregnancy
Alcohol use
Advanced maternal age
Other structural heart defects
Family history of TGA
What are the key symptoms of TGA?
Cyanosis at birth or shortly after
Rapid breathing or SOB
Poor feeding
Low weight gain
Heart murmur - systolic if VSD also present
What investigations should be done for transposition of the great arteries?
Foetal US - detect TGA during antenatal period
Pulse oximetry - oxygen sat levels for severity of cyanosis
ECG - initially normal, later signs of RH strain
CXR - egg on string appearance
Echo - structure and function
What is the temporary treatment for a TGA?
Prostaglandin E infusions -> maintain patency of the DA.
Balloon atrial septostomy -> if intact ventricular septum, used to create passage between atria to enable mixing of blood
What is the definitive management of TGA?
Surgical correction - within first few months of life
Commonly the arterial switch operation to reconnect aorta and pulmonary artery to correct position
Receive long term follow up for heart function and complications
What are the potential complications following surgical correction of TGA?
Pulmonary stenosis
Aortic root dilation or regurg
Coronary artery disease
What is the prognosis of TGA?
Antenate detetion and surgical correction - 95% at 20yrs
Lower prognosis with low gestational age and high pre-operative lactate levels.
