Ultrasound echocardiographic assessment of transmural inhomogeneity of the left ventricular contraction during the heart cycle

Abstract

Functional echocardiographic imaging, based on speckle tracking, has recently gained widespread use. It provides valuable clinical information, but only the longitudinal or circumferential strains are provided. Assessing these measures across the wall has immense diagnostic information. The purpose of this study was to employ a novel technique that allows measuring the left ventricular transmural kinematics in normal subjects. A novel smoothing technique was developed for a speckle tracking imaging program, called 2D-strain, to achieve spatial transmural resolution analysis, and then applied to standard echocardiographic cines. The results show heterogeneity of the left ventricular rotation and circumferential strain across the wall, with large values for the inner layer, and smaller ones for the outer layer. Using standard echocardiography, transmural analysis is feasible, and it may provide early diagnosis of different pathologies that were difficult to attain before.