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