Transthoracic Doppler echocardiography for the assessment of left atrial appendage size and blood flow velocity. A multicentre study

Abstract

Reliable LAA size and blood flow velocities can be obtained by TTE in consecutive, unselected patients. TTE identifies patients with low and high blood flow velocities in the LAA, providing helpful information for the definition of individual embolic risk.

Transthoracic Tissue Doppler Assessment of Left Atrial Appendage Contraction and Relaxation: Their Changes with Aging

“…However, some limitations remain in measuring the flow velocity using a transthoracic approach. Detection rate of measurable flow velocities ranged from 62% to 88% for various heart diseases with sinus rhythm or atrial fibrillation 6,7 . On the other hand, the intravenous contrast injection allows better visualization of the LAA and assessment of blood flow velocities 10 .…”

“…Insertion of the transesophageal probe is semi‐invasive; hence, we hesitate to examine healthy subjects using TEE. Recent development in transthoracic echocardiography (TTE) has facilitated evaluation of the transverse size of the orifice and determination of flow velocities in the LAA, and in some reports, the efficacy of this method has been reported 6,7 . Recently, Uretsky et al demonstrated that transthoracic tissue Doppler echocardiography (TDE) could provide noninvasive physiological analysis of LAA function, and that LAA wall velocity decreased in patients with atrial fibrillation 8 .…”

Assessment of left atrial appendage function by transthoracic pulsed Doppler echocardiography: Comparing against transesophageal interrogation and predicting echocardiographic risk factors for stroke

“…Pulsed Doppler sample was taken at 1 cm into the LAA orifice . To achieve optimal alignment of Doppler beam with LAA flow, the sonographer gradually modified the view by moving upward and downward in the intercostal spaces and adjusting the angle of the probe, as described in previous studies . Offline measurements of LAA E and F velocities were obtained by a trained echocardiologist blinded to TEE and clinical findings.…”

“…Receiver operating characteristic (ROC) curve analysis was then used to determine the optimal cutoff values of TTE LAA E that predicts (1) the presence of thrombus or SEC on TEE and (2) the presence of LAA dysfunction (TEE LAA E ≤ 20 cm/s). As previous studies have found that patients with AF had lower LAA flow velocities, subgroup analysis of patients with AF was also performed …”

“…However, as TTE is noninvasive and routinely used in clinical practice, it is valuable to investigate whether TTE‐derived parameters of LAA function correlate well with TEE measurements and whether TTE can be used to predict the presence of echocardiographic risk factors identified on TEE. Previous studies have attempted to correlate TEE and TTE measurements of various aspects of LAA . The function of LAA has been studied using different TTE techniques including harmonic imaging, contrast‐enhanced imaging, tissue Doppler and pulsed Doppler .…”