In transposition of the great arteries the aorta comes from the right ventricle and the pulmonary artery from the left, so the two circulations run in parallel instead of in series. The baby survives only while blood mixes through the ductus arteriosus, a foramen ovale or a septal defect.
Key symptoms
- Cyanosis in the first hours or days of life
- Blue color that does not improve with oxygen
- Fast breathing, often without much distress
- Poor feeding
What you find on exam
- Central cyanosis with low oxygen saturation
- Saturation that stays low on 100 percent oxygen
- Single loud second heart sound; often no murmur
- Signs of poor perfusion if mixing is limited
Tests
- Newborn pulse oximetry screening
- Echocardiogram confirms the diagnosis
- Chest X-ray: egg on a string shape with a narrow mediastinum
- Blood gas: low oxygen and metabolic acidosis if severe
Treatment basics
- Prostaglandin E1 (alprostadil) infusion to keep the ductus open
- Watch for apnea on prostaglandin and be ready to support breathing
- Balloon atrial septostomy if mixing is poor
- Arterial switch operation in the first weeks of life
- Lifelong cardiology follow-up
Red flags
- Saturation falling despite prostaglandin
- Apnea after starting prostaglandin
- Acidosis, poor pulses or shock
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; NCSBN 2026 NCLEX-RN Test Plan. Written by Making Synapses. Making Synapses is not affiliated with these organizations.