Cardiology · Congenital Heart Disease
The facts most likely to be tested
Coarctation of the aorta presents with brachial-femoral pulse delay and upper extremity hypertension compared to lower extremities.
Physical examination reveals a systolic murmur best heard at the left interscapular area or left infraclavicular region.
Chest X-ray findings in older children or adults demonstrate rib notching due to collateral circulation through enlarged intercostal arteries.
The classic cardiac association is a bicuspid aortic valve, which is present in approximately 50% of patients.
Patients with Turner syndrome (45,X) have a significantly increased risk of developing coarctation of the aorta.
The gold standard for definitive diagnosis and anatomical assessment is CT angiography or cardiac MRI.
Untreated coarctation leads to long-term complications including congestive heart failure, aortic dissection, and intracranial hemorrhage from associated berry aneurysms.
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A 14-year-old male presents for a sports physical. He is asymptomatic, but the physician notes a blood pressure of 155/90 mmHg in the right arm and 100/60 mmHg in the right leg. A systolic ejection murmur is heard at the left sternal border radiating to the back. Palpation reveals diminished femoral pulses compared to the radial pulses. A chest X-ray shows inferior rib notching.
What is the most likely diagnosis?
Coarctation of the aorta
The combination of upper extremity hypertension, lower extremity hypotension, and rib notching is pathognomonic for coarctation of the aorta, testing the classic clinical presentation and radiographic findings.
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Etiology / Epidemiology
Congenital narrowing of the aorta, often associated with Turner syndrome and bicuspid aortic valve.
Clinical Manifestations
Classic brachial-femoral pulse delay and upper extremity hypertension with lower extremity hypotension.
Diagnosis
Echocardiogram is the initial test; CT angiography or MRA is the gold standard for definitive anatomy.
Treatment
Surgical repair or percutaneous balloon angioplasty; prostaglandin E1 to maintain ductal patency in neonates.
Prognosis
Risk of aortic dissection, cerebral aneurysm, and heart failure if left untreated.
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Epidemiology & Etiology
Common congenital heart defect occurring more frequently in males. Strongly associated with Turner syndrome (45,X) and bicuspid aortic valve (present in 50-80% of cases).
Pertinent Anatomy
Narrowing typically occurs at the aortic isthmus, distal to the origin of the left subclavian artery. This anatomical location creates a pressure gradient between the upper and lower body.
Pathophysiology
Obstruction increases left ventricular afterload, leading to left ventricular hypertrophy. Collateral circulation develops via intercostal arteries to bypass the stenosis, causing rib notching on chest X-ray. Chronic hypertension in the upper body predisposes patients to premature atherosclerosis and intracranial hemorrhage.
Clinical Manifestations
Infants may present with heart failure or shock upon closure of the ductus arteriosus. Older children are often asymptomatic but exhibit brachial-femoral pulse delay and a systolic murmur heard best at the left infraclavicular area and back. Red flags include severe hypertension, claudication, and cold extremities.
Diagnosis
Initial screening via echocardiogram confirms the diagnosis. CT angiography or MRA is the gold standard for visualizing the extent of the coarctation and collateral vessels. Look for the 3 sign on chest X-ray due to pre- and post-stenotic dilation.
Treatment
Neonates with severe obstruction require prostaglandin E1 to maintain ductal patency until definitive repair. Surgical correction (e.g., end-to-end anastomosis) is the definitive treatment. Percutaneous balloon angioplasty with or without stenting is an alternative for older children or recurrent cases.
Prognosis
Long-term monitoring is required for re-coarctation and persistent hypertension. Patients remain at increased risk for aortic dissection and cerebral aneurysm rupture even after successful repair.
Differential Diagnosis
Takayasu arteritis: involves aortic arch branches in young females
Aortic dissection: acute onset of tearing chest pain
Pseudocoarctation: kinking of the aorta without pressure gradient
Renal artery stenosis: hypertension without pulse delay
Patent ductus arteriosus: continuous machine-like murmur