Pseudocoarctation of the aorta coexistent with coarctation

Sir: Pseudocoarctation of the aorta is an uncommon congenital anomaly of the aortic arch, usually detected by cardiac murmur or abnormal superior mediastinal mass on the chest radiograph. The criteria for diagnosing this anomaly include the small pressure gradient of the lesion, usually below 25 mmHg, absence of increased collateral circulations and definitive angiogram of an abnormally elongated aortic arch [2]. However, a few cases of pseudocoarctation have been reported in which the arterial pressure gradient between the upper and lower extremities exceeds 25 mm Hg because of coexisting coarctation of the aorta [1, 3-5]. We present here such a rare type of pseudocoarctation. A 9-year-old girl was refened for evaluation of a grade 2/6 continuous heart murmur in the upper area of the chest and back. Physical examination revealed a healthy-appearing girl. Blood pressure was 132/74 m m H g in the right arm, and 80/60 mm Hg in the left arm and lower extremities. An electrocardiogram and echocardiogram showed no hypertrophy of the left ventricle. Radiographs of the chest revealed high aortic knob which reached the clavicle without cardiomegaly. Retrograde cardiac catheterization was performed via the femoral artery. A soft tip catheter barely passed through the kinked portion of the aorta to reach the ascending aorta. Blood pressure in the ascending aorta, aortic arch and descending aorta were 136/86, 98/62 and 88/62 mm Hg, respectively. Intra-arterial digital subtraction angiography showed a normal ascending aorta and coronary arteries. The aortic segment between the left common carotid artery and the left subclavian artery was apparently elongated with localized coarctation distal to the origin of the left common carotid artery [Fig. 1], which yielded most of the pressure gradient. Pseudocoarctation of the aorta has been thought to develop from failure of the normal compression of the third through seventh dorsal aortic arch during fetal development [2]. Although our case did not demonstrate coarctation histologically, it is possible that the ductal tissue or the ligamentum arteriosus play a role in the formation of a localized stenosis of the elongated segment. We emphasize that invasive catheterization and angiography are essential to determine the coexistence of coarctation in cases of pseudocoarctation involving a significant pressure gradient between the extremities. References