Speckle tracking analysis to evaluate the size, shape, and function of the atrial chambers in fetuses with d-transposition of the great arteries to predict the need for neonatal urgent balloon atrial septostomy.

Abstract

Speckle tracking analysis was used to evaluate right (RA) and left (LA) atria size, shape and contractility to create a probability calculator to identify fetuses at risk for urgent neonatal balloon atrial septostomy (BAS). The study group consisted of 39 fetuses with D-TGA, of which 55% (N=22) required neonatal BAS and 45% (N=17) did not. The RA and LA end-diastolic areas, lengths, widths, and sphericity indices as well as global, longitudinal, and transverse contractility were measured with speckle tracking analysis. The z-scores of the measurements were compared to 200 controls. Logistic regression analysis of the computed z-score measurements was performed to separate fetuses requiring urgent neonatal atrial BAS from those who did not. The following z-score values for all fetuses with D-TGA, irrespective of whether they required neonatal BAS, that were significantly less than controls: RA base sphericity index, basal-apical length fractional shortening, fractional area change, lateral wall annular plane systolic excursion (APSE), and longitudinal reservoir strain; LA mid-chamber width, fractional shortening, ejection fraction, basal-apical length fractional shortening, atrial ejection volume, septal wall APSE, and reservoir strain. The following z-score values were significantly larger than control values: RA/LA mid-chamber width, RA/LA base width, and RA mid-chamber length. Logistic regression analysis identified the following five measurements that correctly identified 19 of 22 fetuses requiring urgent neonatal atrial BAS with a sensitivity of 86.4%, a false-positive rate of 11.8% and a positive predictive value of 90.4%: (1) LA mid-chamber transverse fractional shortening, (2) RA mid-chamber end-diastolic width, (3) RA basal-apical length fractional shortening, (4) RA mid-chamber fractional shortening, and (5) RA fractional area change. Using the measurements described in this study identified significant differences between all fetuses with D-TGA and controls, as well as identified measurements that predicted the probability of D-TGA fetuses requiring neonatal septostomy.