ESSENTIALS OF DIAGNOSIS
Usual presentation is systemic hypertension.
Echocardiography/Doppler is diagnostic; a peak gradient of more than 20 mm Hg may be significant due to collaterals around the coarctation reducing gradient despite severe obstruction.
Associated bicuspid aortic valve in 50–80% of patients.
Delayed pulse in femoral artery compared to brachial artery.
Systolic pressure is higher in upper extremities than in lower extremities; diastolic pressures are similar.
Coarctation of the aorta consists of localized narrowing of the aortic arch just distal to the origin of the left subclavian artery. Its development is thought to be related to accessory ductal material that contracts soon after birth. Therefore, it is not usually present in the fetus though it may be associated with aortic root hypoplasia. Some classification schemes localize the coarctation area to the ductus arteriosus and refer to pre-ductal, ductal and post-ductal locations. If the stenosis is severe, collateral circulation develops around the coarctation site through the intercostal arteries and the branches of the subclavian arteries and can result in a lower transcoarctation gradient by enabling blood flow to bypass the obstruction. Coarctation is a cause of secondary hypertension and should be considered in young patients with elevated blood pressure (BP). The renin-angiotensin system is often abnormal, however, and contributes to the hypertension occasionally seen even after coarctation repair. A bicuspid valve is seen in approximately 50–80% of the cases, and there is an increased incidence of cerebral berry aneurysms. Significant native or recurrent aortic coarctation has been defined as follows: upper extremity/lower extremity resting peak-to-peak gradient greater than 20 mm Hg or mean Doppler systolic gradient greater than 20 mm Hg; upper extremity/lower extremity gradient greater than 10 mm Hg or mean Doppler gradient greater than 10 mm Hg when there is either decreased left ventricular (LV) systolic function or aortic regurgitation (AR); or upper extremity/lower extremity gradient greater than 10 mm Hg or mean Doppler gradient greater than 10 mm Hg when there is evidence for collateral flow around the coarctation. This should be coupled with anatomic evidence for coarctation of the aorta, typically defined by advanced imaging (cardiac magnetic resonance, CT angiography).
If cardiac failure does not occur in infancy, there are usually no symptoms until the hypertension produces LV failure. Cerebral hemorrhage, though rare, may occur. Approximately 10% of patients with coarctation of the aorta have intracranial aneurysms identified on magnetic resonance angiography or CT angiography. Increasing age has been identified as a risk factor. Strong arterial pulsations are seen in the neck and suprasternal notch. Hypertension is present in the arms, but the pressure is normal or low in the legs. This difference is exaggerated by exercise. Femoral pulsations are weak and are delayed in comparison with the brachial or radial pulse. A continuous murmur heard superiorly and midline in the back or over the left anterior chest ...