Is combined atrial volumetrics by two-dimensional echocardiography a suitable measure for quantitative assessment of the hemodynamic significance of patent ductus arteriosus in neonates and infants?

BACKGROUND

Patent ductus arteriosus (PDA) is a common cardiac problem in neonates and infants, but determination of its hemodynamic significance can be challenging. We hypothesized that combined left (LA) and right atrial (RA) volumes physiologically best reflect hemodynamically significant patent ductus arteriosus (HSPDA), and utilized two-dimensional echocardiography (2DE) derived atrial volumes to test this hypothesis.

METHODS

2DE examinations with good-quality images in 138 neonates <3 months corrected gestational age with PDA, and 50 normal neonates without PDA were selected. Measurements of LA, RA, and combined atrial volumes were performed, in addition to transductal diameters, left atrial to aortic dimension (LA:Ao), and left ventricular end-diastolic to aortic dimension ratios. An experienced cardiologist, blinded to 2DE images of atria and ventricles and to the above measurements, independently assessed HSPDA based only on images and Doppler data of the ductus itself, thus identifying each PDA as of low hemodynamic significance or HSPDA.

RESULTS

Receiver operating characteristic (ROC) curves showed indexed LA volumes and LA/RA volume ratios to have moderate power to discriminate HSPDA from low hemodynamic burden PDA. Classic LA:Ao ratio, combined atrial volumes, and RA volumes yielded ROC areas that appeared less promising as discriminators for HSPDA.

CONCLUSION

Atrial volume measurements in neonates and infants have a linear association with body surface area and show acceptable inter- and intraobserver agreement. Indexed LA volume and LA/RA volume ratio are potentially useful markers for HSPDA. RA dilation due to left to right shunting through the patent foramen ovale as quantified by RA volume measurements does not appear to be an important marker for HSPDA.