|Echocardiographic Modality||Parameters Evaluated||Comments|
|2D and 3D echocardiography||Visual assessment for the presence of thrombi or other pathologies within the LAA as noted in Table 2.||If there is inadequate visualization or artifacts, ultrasound contrast agents can enhance visualization.|
ICE can serve as a complementary method for evaluation.
|Spectral Doppler||Evaluation of flow in the LAA using pulsed-wave Doppler:|
Velocities >40 cm/s are suggestive of adequate flow within the appendage and a low risk for thrombus formation.
Color Doppler to a low Nyquist limit can aid in visualization of flow within the LAA.
|Easily performed, highly reproducible, and carries relevant clinical implications.|
When Doppler signal is limited, microbubble contrast agent enhances visualization of contractility indices.
|Tissue Doppler and strain imaging||Limited studies.|
E/e' and e' velocity were found to be independently associated with an LAA thrombus in patients with nonvalvular AF.
Compromised LAA contractile fraction, measured by speckle-tracking, strain-based methods, was an independent determinant of LAA thrombus.
|Not routinely used.|
AF = atrial fibrillation; ICE = intracardiac echocardiography; LAA = left atrial appendage; 2D = 2-dimensional; 3D = 3-dimensional.