Epidemiology
Etiology
- Associations (High-Yield)
- Turner Syndrome (45,XO): High association (up to 15% of cases).
- Bicuspid Aortic Valve: Present in >50% of patients.
- Intracranial Berry Aneurysms (risk of subarachnoid hemorrhage).
Pathophysiology
- Narrowing (stenosis) of the aortic lumen.
- Infantile Type (Preductal): Stenosis proximal to the ductus arteriosus. Dependent on patent ductus arteriosus (PDA) for systemic perfusion.
- Adult Type (Postductal): Stenosis distal to the ductus arteriosus (distal to left subclavian).
Clinical features
- Differential cyanosis: cyanosis of the lower extremities
- Brachial-femoral delay: weak femoral pulses
- ↑ Blood pressure (BP) in upper extremities and ↓ BP in lower extremities
- In distal narrowing of the left subclavian artery: ↑ BP in both arms and ↓ BP in both legs
- In origin of left subclavian artery is involved: BP in the right arm > in left arm
- Cold feet and lower-extremity claudication upon physical exertion
- Strong apical impulse displaced to the left
- Headache, epistaxis, tinnitus
- Caused by brachiocephalic hypertension
- Risk factor for cerebral aneurysm development
- In severe stenosis: shock and multiorgan failure when ductus arteriosus closes
- Auscultation
- Systolic ejection murmur over left posterior hemithorax
- Due to blood flow through the aortic narrowing
- Continuous murmur below the left clavicula and between the shoulder blades
Diagnostics
Treatment