What is the role of cardiac catheterization in the workup of coarctation of the aorta (CoA)?

Updated: Nov 20, 2018
  • Author: Syamasundar Rao Patnana, MD; Chief Editor: Stuart Berger, MD  more...
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Cardiac catheterization and selective cineangiography may not be required for diagnosis; however, they allow evaluation of the severity of coarctation, anatomic nature of the aortic obstruction (discrete vs long segment), and arch anatomy, including hypoplasia of the transverse arch or isthmus.

Cardiac catheterization helps to confirm the diagnosis when echocardiography findings are not completely clear, allows the evaluation of intracardiac anatomy and the contribution of associated lesions to the overall hemodynamic disturbance, and is a prerequisite for intervention in the form of either balloon angioplasty or stent implantation in native or recurrent coarctation.

When catheterization is performed, elevations of left ventricular and ascending aortic peak systolic pressures with a peak-to-peak systolic pressure gradient across the coarcted segment are usually found. A peak-to-peak gradient in excess of 20 mm Hg is generally considered indicative of significant obstruction. However, the magnitude of the gradient is not necessarily indicative of the degree of narrowing because the gradient depends on not only the extent of aortic narrowing but also the size and number of collateral vessels. In addition, cardiac output and the state of ductus arteriosus, particularly in the neonate and young infant, also determine the pressure gradient.

Selective aortic root or aortic arch angiography is necessary to clearly demonstrate the aortic narrowing. Aortography is useful in demonstrating the type of aortic coarctation (diffuse, long segment, aortic kinking [pseudocoarctation]); extent of collateral circulation; the size of ductus arteriosus, if patent; and the presence and degree of hypoplasia of transverse aortic arch and aortic isthmus, especially in neonates. If thoracic coarctation is not demonstrated despite clinical features of coarctation or if neurofibromatosis is suspected, abdominal aortography may be needed to demonstrate (or exclude) abdominal coarctation.

LV angiography is particularly useful in neonates and infants who demonstrate ventricular septal defects (VSDs) and in evaluating LV function.

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