Review of speckle tracking analysis to measure the size, shape, and contractility of the fetal heart in fetuses with congenital heart defects

Evaluation of the fetal heart involves two approaches. The first describes a screening protocol in which the heart is imaged in transverse planes that includes the four-chamber view (4CV), left and right outflow tracts, and the 3-vessel-tracheal view. The second approach is a fetal echocardiogram that requires additional cardiac images as well as evaluating ventricular function using diagnostic tools such as M-mode and pulsed Doppler ultrasound. Speckle tracking analysis of the ventricular and atrial endocardium of the fetal heart has focused primarily on computing longitudinal global strain. However, the technology enabling this measurement to occur has recently been adapted to enable the clinician to obtain numerous additional measurements of the size, shape, and contractility of the ventricles and atrial chambers. By using the increased number of measurements derived from speckle tracking analysis, we have reported the ability to screen for tetralogy of Fallot, D-transposition of the great arteries (D-TGA), and coarctation of the aorta by only imaging the 4CV. In addition, we have found that measurements derived from speckle tracking analysis of the ventricular and atrial chambers can be used to compute the risk for emergent neonatal balloon atrial septostomy in fetuses with D-TGA. The purpose of this review is to consolidate our experience in one source to provide perspective on the benefits of speckle tracking analysis to measure the size, shape, and contractility of the ventricles and atria imaged in the 4CV in fetuses with congenital heart defects. Speckle tracking analysis, which measures 24 transverse segments and one length measurement, is used to examine the ventricular and atrial chambers. The graphic illustrate the measurements used in the computations of the size, shape, and contractility of the ventricles and atrial chambers. Using speckle tracking analysis, z-scores of the measurements have been used to identify fetuses with various congenital heart defects which are listed on the right of the image with their corresponding sensitivity and false-positive rate (FPR) For the ventricles the graphic images B to G illustrate the measurements below each graphic. For images A to D for the atria, the graphics illustrate the measurements. D, end-diastole; ED, end-diastole; ES, end-systole; LA, left atrium; LV, left ventricle; RA, right atrium; RV, right ventricle; S, end-systole; S, segments. image