Tissue Doppler and speckle tracking strain echocardiography : from evaluation in healthy children to follow-up after surgery for a congenital heart defect

Abstract

This thesis provides insights in characteristics of newly introduced echocardiographic parameters in healthy children and their use in follow-up of patients with a congenital heart defect (CHD) after surgery. In healthy children, reference values and characteristics of two echocardiographic techniques, tissue Doppler imaging (TDI) and speckle-tracking strain imaging, are described. TDI-derived velocity parameters are reproducible and feasible in children. Yet use of age or growth-dependent reference values is recommended, especially in neonates. Speckle-tracking strain-derived global peak strain parameters have a good reproducibility, are age-independent and remain unchanged during periods of significant growth, such as the neonatal period. We encourage use of these parameters. In contrast, the limited reproducibility of parameters describing intraventricular time-differences is worrying. Our follow-up studies in CHD patients undergoing corrective surgery with cardiopulmonary bypass, describe a significant decrease in biventricular performance immediately postoperatively. Subsequently, left ventricular performance recovered to control values. In contrast, right ventricular performance remained impaired in most subgroups of CHD patients up to one year postoperatively. Considering the prognostic value of right ventricular performance parameters, these studies underline the need for careful evaluation of both left and right ventricular performance postoperatively. Furthermore, a longer-lasting negative influence of cardiopulmonary bypass on ventricular performance was suggested.