Abstract
This study explored the value of routine transthoracic echocardiography (TTE) combined with two-dimensional speckle tracking echocardiography (2D-STE) for the early evaluation of left ventricular remodeling in the hypertensive immature rabbit model. Twenty-seven New Zealand white rabbits were divided into Group A (sham-operated group), Group B (mild group), and Group C (severe group), with 9 rabbits per group. The hypertension model was constructed using the "two kidneys one clip" method. Changes in left ventricular function and the degree of left ventricular wall thickening were observed by TTE at 1, 4, and 8 weeks after modeling. The global longitudinal strain (GLS-AVG, GLS-A4C, GLS-A2C, and GLS-LAX) of the left ventricle (LV) and the longitudinal strain (LS) of the 18 segments of left ventricular myocardium were analyzed using 2D-STE. Concurrently, LV myocardial tissue was sampled for HE staining and Masson staining. Receiver operating characteristic (ROC) curves were plotted to evaluate the accuracy of 2D-STE parameters in predicting myocardial fibrosis. The model group exhibited varying degrees of left ventricular remodeling. GLS-A4C, GLS-A2C, GLS-LAX, and GLS-AVG in the model group increased at 1 week after modeling (P < 0.01), with LS abnormalities concentrated in the apical segments. GLS-AVG showed a significant positive correlation with both IVSd and CVF (P < 0.01). The area under the curve (AUC) values of GLS-AVG, GLS-A4C, GLS-A2C, and GLS-LAX were 0.850, 0.827, 0.839, and 0.800, respectively. This study demonstrates the promise of TTE combined with 2D-STE for the early and comprehensive evaluation of left ventricular myocardial damage in hypertensive children in the clinical setting.