Clinical Utility of Multimodality LA Imaging

Abstract

The reservoir, conduit, and contractile functions of the left atrium are integral to overall cardiac performance. Recent advances in cardiac imaging offer the accurate assessment of LA phasic functions and structure, using techniques such as 3-dimensional echocardiography, color tissue Doppler imaging, and speckle tracking, as well as cardiac computed tomography and magnetic resonance imaging. These new developments are particularly important in view of the increasing use of intervention involving the left atrium. This review article highlights and contrasts the imaging of the size, mechanics, and structure of the left atrium using multiple modalities. The authors discuss recent studies on the clinical applications of the various techniques in disease conditions.

Assessment of Left Atrial Deformation and Function by 2‐Dimensional Speckle Tracking Echocardiography in Healthy Dogs and Dogs With Myxomatous Mitral Valve Disease

“…Assessment of LA function is essential for clinical evaluation and prognostic purposes in dogs affected by myxomatous mitral valve disease (MMVD) 2. Several methods have been used to assess LA function in humans, including 2‐dimensional (2D) and 3‐dimensional echocardiography, computed tomography, and magnetic resonance 3, 4. In dogs, the majority of studies have been focused on conventional echocardiographic variables, such as calculation of LA phasic sizes (areas and volumes),5, 6, 7, 8 and pulsed‐wave Doppler evaluation of transmitral and pulmonary venous flow 9.…”

“…However, most of the studied echocardiographic parameters of LA function are highly preload dependent and they are influenced by changes in hemodynamic load associated with mitral regurgitation (MR), thus raising the need for more sophisticated echocardiographic techniques 10. Assessment of atrial deformation profiles obtained by tissue Doppler imaging (TDI) and its derived variables, strain and strain rate, has been recently proposed as an alternative method of exploring LA mechanics in both humans3, 4, 10 and dogs 11. Nevertheless, a number of potential drawbacks of this approach should be considered, including suboptimal reproducibility, angle dependence, and the confounding effect of noise artifacts 3, 4, 10, 11.…”

“…Assessment of atrial deformation profiles obtained by tissue Doppler imaging (TDI) and its derived variables, strain and strain rate, has been recently proposed as an alternative method of exploring LA mechanics in both humans3, 4, 10 and dogs 11. Nevertheless, a number of potential drawbacks of this approach should be considered, including suboptimal reproducibility, angle dependence, and the confounding effect of noise artifacts 3, 4, 10, 11. Many of these limitations might be overcome by 2D speckle tracking echocardiography (STE), the most recent and promising ultrasound technology for the direct evaluation of LA function from standard grayscale echocardiographic images 3, 4, 10.…”

“…Nevertheless, a number of potential drawbacks of this approach should be considered, including suboptimal reproducibility, angle dependence, and the confounding effect of noise artifacts 3, 4, 10, 11. Many of these limitations might be overcome by 2D speckle tracking echocardiography (STE), the most recent and promising ultrasound technology for the direct evaluation of LA function from standard grayscale echocardiographic images 3, 4, 10. Specifically, regional myocardial deformation can be calculated from continuous frame‐by‐frame tracking of the tiny echo‐dense speckles created by the interference between the ultrasound beam and myocardium.…”

“…The movement of the speckle during the cardiac cycle follows myocardial movement, and a change between speckles is assumed to represent myocardial deformation. In this manner, STE allows for the assessment of myocardial function independent of cardiac translation and angle of insonation 3, 4, 10. In people, reference range values, feasibility, and reproducibility of STE for the study of LA mechanics have been extensively documented 12, 13, 14, 15.…”