Tga Flashcards
(101 cards)
What is Transposition of the Great Arteries (TGA)?
A congenital heart defect where the aorta arises from the right ventricle and the pulmonary artery from the left ventricle.
What are the two isolated circulations in TGA?
Systemic and pulmonary circulations, which are separate and incompatible with life without communication.
Why is communication between circulations necessary in TGA?
To allow mixing of oxygenated and deoxygenated blood for survival.
What is the clinical presentation of TGA at birth?
Central cyanosis, which is deep and seen in the tongue, lips, and limbs.
What is the role of the ductus arteriosus in TGA?
It provides a temporary communication between the systemic and pulmonary circulations.
What are the symptoms of TGA in infants?
Cyanosis, dyspnea, feeding difficulties, and failure to thrive.
What is the significance of cardiomegaly in TGA?
It indicates an enlarged heart due to increased workload.
What is the ‘Egg on side’ appearance on chest X-ray in TGA?
A characteristic heart shape seen in TGA due to the abnormal position of the great vessels.
What is the role of echocardiography in diagnosing TGA?
It confirms the abnormal connection of the great vessels and assesses heart function.
What is the treatment for TGA in newborns?
Prostaglandin infusion to keep the ductus arteriosus open and urgent surgical correction.
What is the pathophysiology of cyanosis in TGA?
Oxygenated blood circulates only in the lungs, and deoxygenated blood circulates in the body, leading to systemic desaturation.
What is the role of an atrial septostomy in TGA?
It creates a communication between the atria to allow mixing of blood.
What is the significance of the ‘Boot-shaped’ heart on chest X-ray?
It is seen in Tetralogy of Fallot, not TGA, and indicates right ventricular hypertrophy.
What is the role of the Rashkind procedure in TGA?
It is a balloon atrial septostomy to create a communication between the atria.
What is the arterial switch operation in TGA?
A surgical procedure to correct TGA by switching the aorta and pulmonary artery to their correct positions.
What are the complications of untreated TGA?
Heart failure, recurrent chest infections, and brain abscess due to chronic hypoxia.
What is the significance of polycythemia in TGA?
It is a response to chronic hypoxia, increasing the risk of thrombosis.
What is the role of cardiac catheterization in TGA?
It can be used for diagnosis and treatment, such as performing an atrial septostomy.
What is the significance of a narrow cardiac waist on chest X-ray in TGA?
It is due to the abnormal position of the great vessels.
What is the role of prostaglandins in TGA?
They keep the ductus arteriosus open, allowing temporary mixing of blood.
What is the embryological cause of TGA?
Failure of the aorticopulmonary septum to spiral during development.
What is the significance of the ‘Egg on string’ appearance on chest X-ray in TGA?
It is due to the abnormal position of the great vessels and the narrow mediastinum.
What is the role of the left ventricle in TGA before and after the arterial switch operation?
Before surgery, the left ventricle pumps blood to the lungs; after surgery, it pumps blood to the body.
What is the significance of the ‘Mustard’ or ‘Senning’ procedure in TGA?
They are atrial switch procedures that redirect blood flow but are less commonly used now.