Epidemiology
Etiology
- Often accompanied by a bicuspid aortic valve , VSD, and/or PDA
Pathophysiology
- Genetic defects and/or intrauterine ischemia → medial thickening and intimal hyperplasia → formation of a ridge encircling the aortic lumen → narrowing of the aorta → ↑ flow proximal to the narrowing and ↓ flow distal to the narrowing
- Coarctation is most commonly juxtaductal.
- The coarctation most commonly occurs distal to the left subclavian artery, where the ductus arteriosus originates.
- Rarely, the coarctation occurs in the lower segments of the thoracic aorta or in the abdominal aorta
- In discrete coarctation: left ventricular outflow obstruction → myocardial hypertrophy and increased collateral blood flow (e.g., intercostal vessels, scapular vessels).
- In long-segment coarctation: closure of PDA after birth → left ventricular pressure and volume overload → hypoperfusion of organs and extremities distal to the stenosis
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