Left atrial regional strain assessed by novel dedicated three-dimensional speckle tracking echocardiography

BACKGROUND Left atrial (LA) global strain has been studied as an early marker of LA dysfunction, followed by LA dilatation. Recently, a novel dedicated software for LA 3-dimensional speckle tracking echocardiography (LA-3DSTE) has allowed us to assess anatomy-based six-segmental LA deformation. This study aimed to assess the accuracy of LA-3DSTE software in measuring LA volume and to reveal the characteristics of regional LA reservoir strain. METHODS Fifty patients with paroxysmal atrial fibrillation who underwent computed tomography (CT) and 3D-STE were enrolled. The LA volumes obtained by 3D-STE and CT were compared, and regional LA strain was analyzed. Six LA segments (anterior, septal, inferior, lateral, roof, and posterior) were determined on the basis of LA anatomy. RESULTS In 50 patients (mean age, 64 years; 62% male), the 3D-STE-derived LA volume index (LAVI) showed good correlation with the CT-derived index, (r = 0.78, p < 0.001) with an underestimate bias of 10.5 ± 11.0 ml/m2 (p < 0.001). The lateral LA strain was negatively correlated with LAVI and emptying fraction, while the anterior and septal strains were not. In the 1st quantile LA volume group, the segmental LA strain was heterogeneous, that is, the lateral and inferior strains were greater than the anterior strain. While in the 3rd quantile LA volume group, the lateral and inferior strains were decreased, and there was no regional difference. CONCLUSION LA volume obtained by 3D-STE and CT showed a good correlation. LA segmental analysis by 3D-STE enables early identification of how LA dysfunction affects lateral and inferior LA strains, consistent with anatomical features.