Evaluation of the Adequacy of Blood Mixing by Echocardiographic Parameters in Neonates with the Transposition of Great Arteries

Objective: Transposition of the great arteries (TGA) is one of the major causes of cyanotic heart disease in neonates and should be treated surgically in the early stages of life. In these patients, adequate blood mixing between systemic and pulmonary blood flow is required until surgery, and interatrial communication plays a major role during this period. This study aimed to evaluate the echocardiographic factors used to predict adequate interatrial communication with echocardiographic data.
Material and Methods: This study included newborn patients (who were) followed up in the pediatric cardiac intensive care unit with the diagnosis of simple TGA between August 1, 2020, and February 1, 2021. Patients were classified into those who underwent balloon atrial septostomy (BAS) (group I) and those who did not undergo BAS (group II). The atrial septal defect (ASD) size, interatrial septum (IAS) length, peak/mean interatrial pressure gradient, transverse diameter of the left atrium (LA), transverse diameter of the right atrium (RA), and the following ratios; ASD/IAS, LA/RA, mitral/tricuspid valve annulus, peak gradient of ASD/ASD diameter and ASD diameter/(LA: RA ratio) were calculated echocardiographically. The results were evaluated statistically.
Results: Eighteen patients were included (6 patients in group I and 12 patients in group II) during the study period. The median age was 3 days (interquartile range 2 days-7 days). 50% of the cases were male, and 50% were female. ASD peak gradient, ASD mean gradient, ASD peak gradient/ASD diameter, and LA: RA ratios were significantly higher, and ASD size, ASD diameter/(LA: RA ratio) were significantly lower in the group I compared in group II (p<0.05). ASD diameter/(LA: RA ratio) was found to independently predict the need for BAS with a cut-off value of 2.7 by multivariate analysis.
Conclusion: The echocardiographic measurement of ASD diameter/(LA: RA ratio) in TGA patients may be helpful in the prediction of BAS requirement.