Transposition of the Great Arteries

Transposition of the Great Arteries is a cyanotic heart defect when the aorta and pulmonary artery are connected to the wrong chambers.

• TGA occurs due to the development of clonal tissue in the fibrous skeleton of the heart.
• Oxygenated blood returns to the left atrium and ventricle, but is circulated back to the lungs due to the wrong pulmonary connections.
• This results in deficient oxygen supply to the tissues, and an increase in ventricular workload.
• Due to the tissues not getting enough oxygen, this can cause hypoxia and cyanosis.
• The child would be unlikely to survive without surgical intervention.

• Cyanosis - skin may have a blue tinge due to blood bypassing the lungs and going straight to the body.  More common around the mouth, lips and toes.
• Hypoxia - due to lack of oxygen in the blood.
• Lack of Appetite - in infants as they may feel fatigued, interrupting their feeding.
• Poor Weight Gain - in infants due to lack of appetite.

• Oxygen - To reverse hypoxia due to insufficient oxygen getting to the tissues.
• Prostaglandin Infusion - To ensure the ductus arteriosus stays open which allows the blood to mix from the pulmonary artery to the aorta.
• Baloon Septostomy - A catheter is inserted through a vein in the groin and passed up to the heart.  It is pulled through to the left atrium and a balloon is inflated and pulled into the right atrium through the Foramen Ovale.  This generally tears some of the muscle, making the hole bigger.
• Surgical Correction (Arterial Switch) - This should be done in the first few weeks of life.  The aorta and pulmonary artery are surgically switched around, and the coronary arteries are cut out of the pulmonary artery and connected to the aorta.