Abstract 1869: Real-Time Three-Dimensional Echocardiography of the Left Atrial Appendage: Initial Experience in Humans with Validation by 64-Slice Computed Tomography

Abstract

Background: Real-time left atrial appendage (LAA) quantification is increasingly important with the advent of LAA occluder devices for stroke prevention. However, accurate quantification is difficult using 2D-TEE because measurements must be made in multiple views, and LAA orifice cannot be viewed directly. We aimed to determine the accuracy of LAA geometry measured by a new matrix-array (mTEE) probe which can provide unique real-time 3D (RT3D) views of the LAA. Methods: 29 consecutive patients (age 53±18) referred for 2D-TEE underwent additional RT3D-mTEE (Philips ie33; frame rate 8–10/s). The LAA orifice diameter and LAA depth were measured from biplane 2D images, and 2D LAA orifice area was calculated as an ellipse. LAA orifice area and LAA depth were measured in 3D and correlated to 2D. In 8 patients who had cardiac CT available, 2D- and 3D-TEE LAA measurements were correlated with 64-slice CT. All LAA measurements were made at atrial end-diastole. Results: All 29 patients underwent RT3D-mTEE without complication. The LAA was well-visualized in 3D in 26/29 (90%). Because the shape of the LAA orifice in 3D was an ellipsoid with an irregular contour, 2D images resulted in underestimation of area vs. 3D (3.0±1.2 vs. 4.2±2.2 cm 2 ). LAA depth by 2D and 3D correlated well (3.7±0.7 vs. 3.4±0.7; r=0.72, p=0.001). CT LAA orifice area correlated well with 3D-TEE (r=0.98, p<0.0001) but not with 2D-TEE (p=0.78). Conclusions: RT3D-TEE for analysis of LAA geometry is safe and feasible and appears to be more accurate than 2D-TEE. RT3D-TEE provides unique visualization of the LAA orifice in real-time, making it the ideal tool for intra-procedural sizing and placement of LAA occluder devices.