In these cases, a difference between the normal radial pulse in the right arm and the delayed femoral pulse in the legs (either side) may be apparent, whilst no such delay would be appreciated with palpation of both delayed left arm and either femoral pulses. On the other hand, a coarctation occurring after the left subclavian artery will produce synchronous radial pulses, but radio-femoral delay will be present under palpation in either arm (both arm pulses are normal compared to the delayed leg pulses). Diagnosis
With imaging, resorption of the lower part of the ribs may be seen, due to increased blood flow over the neurovascular bundle that runs there. Prestenotic dilatation of the aortic arch and left subclavian artery, as well as indentation at the site of coarctation results in a classic figure 3 sign on x-ray. The characteristic bulging of the sign is caused by dilatation of the aorta due to an indrawing of the aortic wall at the site of cervical rib obstruction, with consequent poststenotic dilatation. This physiology results in the 3 image for which the sign is named. When the esophagus is filled with barium, a reverse 3 or E sign is often seen and represents a mirror image of the areas of prestenotic and poststenotic dilatation.Coarctation of the aorta can be accurately diagnosed with magnetic resonance angiography.
Some children born with coarctation of the aorta have additional heart defects, such as aortic stenosis, ventricular septal defect, patent ductus arteriosus or mitral valve abnormalities.Coarctation is about twice as common in boys as it is in girls. It is frequently found in girls who have Turner syndrome.Symptoms may be absent with mild narrowings (coarctation). When present, they include breathing difficulties, poor appetite or trouble feeding, and failure to thrive. Later on, children may develop symptoms related to problems with blood flow and an enlarged heart. They may experience dizziness or shortness of breath, fainting or near-fainting episodes, chest pain, abnormal tiredness or fatigue, headaches, or nosebleeds. They have cold legs and feet or have pain in their legs with exercise (intermittent claudication).In cases of more severe coarctations, babies may develop serious problems soon after birth because not enough blood can get through the aorta to the rest of their body. Arterial hypertension in the arms with low blood pressure in the lower extremities is classic. In the lower extremities, weak pulses in the femoral arteries and arteries of the feet are found.The coarctation typically occurs after the left subclavian artery. However, if situated before it, blood flow to the left arm is compromised and asynchronous or radial pulses of different "strength" may be detected (normal on the right arm, weak or delayed on the left), termed radio-radial delay.