How can PDA mask a coarctation of aorta?

How can PDA mask a coarctation of aorta?

Coarctation of aorta may be missed when there is a large patent ductus arteriosus. This is because the ampulla of the ductus arteriosus is typically across the narrowed segment of aorta in coarctation of aorta. The wide ampulla in a way ameliorates the obstruction, making clinical detection of coarctation difficult. A good pulse can be felt in the lower limbs in such situations. There could be sudden deterioration with shock and mult-organ failure when such an associated patent ductus arteriosus is closed in an infant with an undetected coarctation of aorta. Detection of coarctation could also be difficult by transthoracic echocardiogram in some such cases. Transesophageal echocardiography by better delineation of the structures due to higher resolution, may provide more diagnostic information in such cases [1].

Reference

  1. Liu F, Hsiung MC, Song H, Dian K, Tang H, Liu J. Unexpected co-arctation of aorta detected by transesophageal echocardiography during patent ductus arteriosus ligation. Front Med. 2013 Jun;7(2):270-3. doi: 10.1007/s11684-013-0261-7. Epub 2013 May 17. PMID: 23681889.