Aortic coarctation is one of the more common congenital cardiovascular malformations, but it can sometimes be overlooked clinically. The main pathology involves a localized narrowing of the aortic lumen. Based on the relationship between the coarctation site and the ductus arteriosus, it is divided into preductal and postductal types—the former also called the complex type, and the latter the simple type. In the preductal type, the narrowing typically occurs between the left subclavian artery and the ductus arteriosus, with a longer segment of involvement. The ductus arteriosus often remains patent and has a large lumen, with the descending aorta primarily supplied by the pulmonary artery through the ductus. This type is frequently associated with bicuspid aortic valve and ventricular septal defects. In the postductal type, the coarctation is located distal to the origin of the left subclavian artery, near the ligamentum arteriosum. The lesion is usually more localized, and the ductus arteriosus is often closed. Blood flow to the descending aorta is maintained through collateral circulation and the narrowed aorta. This type is less likely to be accompanied by other malformations and has a better prognosis.

bubble_chart Auxiliary Examination

1. X-ray examination: Often shows left ventricular enlargement, widening of the ascending aortic pulse, and in severe cases, left atrial enlargement may also be present. In older children, rib notching may be visible on both sides between the 4th and 8th ribs. The aortic pulse often presents a "3"-shaped image: the first bulge is the aortic pulse above the coarctation, the second is the post-coarctation dilated segment, while the aortic pulse at the coarctation site contracts toward the midline, forming a localized indentation.
2. Electrocardiogram: Shows left ventricular hypertrophy, with many adolescents exhibiting low or inverted T waves. Preductal types often display right axis deviation, right ventricular hypertrophy, or possible biventricular hypertrophy.
3. Echocardiography: A long-axis view of the aortic arch can reveal the coarctated aorta. Left ventricular enlargement and other associated anomalies such as ventricular septal defects or bicuspid aortic valve can be detected. Pulsed Doppler can identify systolic turbulent flow spectra distal to the coarctation.
4. Cardiac catheterization and angiography: Retrograde aortic catheterization can measure the pressure gradient across the coarctation. In preductal types, the catheter often enters the ductus arteriosus more easily than the aortic arch. Retrograde aortography can determine the location, extent, and severity of the coarctation, assess the pre- and post-coarctation aorta and collateral circulation, and detect the presence of any associated anomalies.

bubble_chart Diagnosis

1. Symptoms: Due to high blood pressure in the upper limbs, symptoms such as headache, dizziness, pulsation of head vessels, palpitation, shortness of breath, and epistaxis may occur. Insufficient blood supply to the lower body can lead to weakness, coldness, numbness, easy fatigue, or even intermittent claudication. In preductal cases, symptoms appear early, with cyanosis in the lower limbs at birth while the upper limbs remain normal.
2. Signs: High blood pressure in the upper limbs and low blood pressure in the lower limbs, with absent or weakened femoral pulses. Dorsalis pedis pulses are often undetectable. Preductal cases exhibit cyanosis in the lower limbs accompanied by clubbing of the toes. Sometimes, increased pulsations may be observed in the sternum and supraclavicular fossa, which are also reliable signs of this condition. Continuous murmurs can be heard in any vascular area with collateral circulation, such as between the scapulae or along the internal thoracic arteries on both sides of the anterior chest. The apical impulse is strong, and the cardiac dullness extends downward and to the left. At the base of the heart or in the left scapular region, systolic ejection murmurs may be heard, possibly accompanied by a thrill, as well as collateral circulation murmurs. In cases with aortic valve deformity, a diastolic murmur of aortic insufficiency may also be audible.

bubble_chart Treatment Measures

For patients with simple type and upper limb hypertension, sudden exertion should be avoided, and active prevention and treatment of cerebrovascular accidents and bacterial endocarditis should be implemented. Surgical treatment involves end-to-end anastomosis at the coarctation segment. If the coarctation is extensive, a prosthetic vascular graft may be performed. To avoid excessive blood loss during surgery, a prosthetic vascular bypass with end-to-side anastomosis at the proximal and distal ends of the coarctation can also be performed. Treatment for the complex type is more challenging, with a poorer prognosis. Surgical mortality is high during infancy, and complications involving complex malformations are common. Older children tend to have better treatment outcomes.