Effect of significant ventricular septal defect on the left atrial function and strain using three-dimensional speckle tracking echocardiography

Introduction Among the various types of congenital heart diseases (CHDs), significant left-to-right shunts such as ventricular septal defects (VSDs) alter normal cardiac physiology and hemodynamics, leading to increased volume load on the left atrium (LA). Assessing LA function and strain in pediatric patients with significant VSDs is of paramount importance for understanding its impact on cardiac mechanics. Recent advancements in echocardiographic techniques, particularly the introduction of three-dimensional echocardiography(3DE), have provided unprecedented insights into LA myocardial mechanics by allowing real-time visualization and quantification of myocardial deformation. Understanding the alterations in LA mechanics in this specific population can have significant clinical implications. Purpose This study aims to investigate the utility of 3DE for the assessment of LA function and strain in pediatric patients with significant VSDs. Methodology: This was a prospective cross-sectional observational study that included 2 groups of pediatric age patients (5- 12 years), age and gender matched with significant ventricular septal defects (VSDs) over 12 months. The first group consisted of patients with non-significant VSD shunts (echocardiographic QP/QS <1.5), while the Second group consisted of patients with significant VSD shunts (echocardiographic QP/QS>1.5-2). All patients underwent 3D speckle-tracking echocardiography for left atrial performance assessment. Results A total of 40 patients with VSDs were included, with the first group(n=20) mean age of 7.40±2.17 and a mean BSA of 0.89±0.15, while the second group(n=20) mean age of 8.90±2.02 and a mean BSA of 0.95±0.20. 3DE data for LA volume quantification revealed that patients with significant VSD shunts had significantly higher indexed left atrial volume at maximum (LAVi max) (p-value = 0.001) and indexed left atrial volume at minimum (LAVI min) (p-value = 0.001). Regarding 3D left atrial strain parameters, patients with significant VSD shunts had significantly lower average reservoir strain (LASr) (p-value = 0.001), average conduit strain (LAScd) (p-value = 0.001), and average contractile strain (LASct) (p-value = 0.001). Left atrial ejection fraction (LA EF) and strain parameters, assessed via 3DE, including longitudinal and circumferential reservoir, conduit, and contractile strain, demonstrated a strong inverse correlation with factors such as body surface area (BSA), age, and the echocardiographic QP/QS. Specifically, as the age and BSA increase, the LA EF and strain parameters tend to decrease. Also, there was a significant inverse correlation with various 3D left atrial volume parameters. Conclusion This study proves that the left atrial function and strain are directly affected by the significance of the VSD, and 3D speckle tracking echocardiography (STE) effectively evaluates the impact of QP/QS ratios on left atrial (LA) volume and function in congenital defects.3D LA strain in VSD patients Bar chart