Abstract 12432: Left Atrial Structure and Function in Hypertensive Patients Assessed by Real-Time Three-Dimensional Speckle Tracking Echocardiography: A Comparative Study with Two-dimensional Speckle Tracking and Three-dimensional Computed Tomography

Abstract

Background: Two-dimensional speckle tracking echocardiography (2-DSTE) using Simpson’s rule has been recently used to assess left atrial (LA) structure and function. However, 3-DSTE has a major advantage of the improvement of accuracy in evaluation of cardiac chamber volume without any geometrical assumption. We evaluated LA volume and function in hypertensive patients (HT) by 3-D and 2-DSTE and validated the accuracy by 3D-CT.

Methods: 3-DSTE (Artida) can provide time-LA volume curve with volume rate 30-40vps. LA phasic volume (max., min. and pre-atrial contraction volume) and phasic function (total, passive and active emptying function (EF)) were measured by 3-D and 2-DSTE in apical 4-chanber view in 34 patients with HT (BP 135±5/80±6mmHg) and 24 normal subjects. LA volume and EF assessed by 2-D and 3-DSTE were validated by 3D-CT (n=24). Left ventricular (LV) mass, ejection fraction and E/e’ were also measured.

Results: There was a good relation in LA volume between 3-D and 2-DSTE (r=0.78, p<0.01), and better relation between 3-DSTE and 3D-CT (r=0.98, p<0.01) than between 2-DSTE and 3D-CT (r=0.90, p<0.01). Although LA min. volume by 2-DSTE was similar to 3-DSTE (28±13 vs. 28±10ml), 2-DSTE overestimated LA max. volume compared to 3-DSTE (56±18 vs. 52±13ml, p<0.05), resulted in overestimation of LA total EF compared to 3-DSTE (50±12 vs. 46±9%, p<0.05) despite no difference in strain between 2-D and 3-DSTE. In HT, LA passive EF by 3-DSTE was significantly decreased associated with increased LV mass and E/e’ compared to normal (15±7 vs. 27±8%, 109±29 vs. 84±18 g/m², 10.2±2.1 vs. 7.2±1.4, respectively) and LA active EF by 3-DSTE was increased associated with increased pre-atrial contraction volume compared to normal (35±8 vs. 29±10% and 29±8 vs. 20±6 ml/m²,p<0.05, respectively).

Conclusion: 2-DSTE overestimated LA volume and function according to LA size. 3-DSTE had an excellent correlation with 3D-CT in assessment of LA volume and showed that LA conduit function in HT was decreased associated with increased LV mass and impaired diastolic function and that booster pump function was increased associated with increased pre-atrial contraction volume, suggesting Frank-Starling law in LA in mild HT. 3-DSTE is a promising method to evaluate LA structure and function.