Most patients with coarctation of aorta appear well in the first 48 hours of life with normal newborn examination. Symptoms develop after discharge from newborn nursery. The extent of ductus arteriosus patency, and the rapidity of closure in addition to pulmonary vascular resistance will determine the timing and severity of presentation. This child's clinical presentation is classic for coarctation of aorta as the ductus arteriosus usually closes anatomically between 2 to 3 weeks of life,6
hence, pediatrician and general practitioners should be aware about the possibility of coarctation of aorta in a newborn with respiratory distress around this period of time.
Classically described, the narrowing could be proximal (preductal) to the ductus arteriosus and the blood flow in aorta distal to the narrowing is dependent on the ductus arteriosus and this is the most common type in neonates, hence, closure of the duct will result in early severe neonatal presentation. In post-ductal COA, the narrowing is distal to insertion of the ductus arteriosus and this is the common type in adult patients. Weak or absent femoral pulses are present in 92% of patients.3
Pulse oximetry measurement at pre- and post-ductal sites should be monitored. In case of critical coarctation of aorta, the preductal saturation is higher than the post-ductal saturation and differential cyanosis exist.7
The four limb blood pressures is an important examination tool and can identify discrepancy between upper and lower limb systolic blood pressure; however, this test lack specificity and discrepancy up to 20 mmHg could be normal which raise the importance of checking femoral pulses in all newborns.8
The electrocardiograph will show features of right ventricular hypertrophy although this could be normal in newborn period. The finding of extreme right axis deviation of 180 degrees or more or an axis in the right upper quadrant should raise the suspicion as these values are above the age appropriate reference range.9
During fetal life, the right ventricle is the systemic ventricle as the oxygenation is taking place in placenta. The right ventricle handles more blood when there is left side obstruction and compensatory hypertrophy will take place and this will result in features of right ventricle hypertrophy in ECG.
There is a long list of differential diagnoses for such presentation as left side obstructive lesions in the newborn period like for example interrupted aortic arch and hypoplastic left heart syndrome. The initial steps of management are hemodynamic stabilization with prostaglandin E2 infusion to open the ductus arteriosus which can be accomplished in 80% of patients up to age of 28 days. After starting the PGE2 infusion, patient should be monitored in critical care unit and periodic check for quality of femoral pulses and four limbs BP to check for response. Due to increase in plasma renin activity secondary to renal hypoperfusion, volume expansion should be treated by reducing preload with the use of diuretics. These measures should correct the metabolic acidosis which occur secondary to congestive heart failure. Postoperatively, such patients require a lifelong follow-up for any complications that might occur for example restenosis, aneurysm formation and development of systemic hypertension.10