Right Ventricular Systolic Assessment by Transesophageal Versus Transthoracic Echocardiography: Displacement, Velocity, and Myocardial Deformation

Abstract

First, to compare tricuspid annular displacement and velocity in transthoracic and transesophageal echocardiography (TTE, TEE) using conventional angle-dependent technologies. Second, to evaluate both alternative TEE views as well as an alternative technology (speckle tracking) for overcoming proposed differences in TTE and TEE. Prospective, comparative, cross-over study with a randomized order of image acquisition. University hospital. Adults undergoing cardiac surgery. Postinduction standardized image acquisition and analysis in TTE and TEE by 2 echocardiographers. The authors measured tricuspid annular plane systolic excursion (TAPSE) by M-mode and velocity by tissue Doppler (S') in the apical 4-chamber TTE view and midesophageal 4-chamber TEE view (AP4C, ME4C). They then examined (1) the same measurements in alternative TEE views with proposed better ultrasound angulation; and (2) speckle tracking-based endpoints (TAPSE by speckle tracking, strain, and strain rate). Data were available in 24 of 25 patients. Conventional TAPSE by M-mode and velocity by tissue Doppler (TDI) were underestimated in the ME4C compared with the AP4C reference (mean ± standard deviation: TAPSE: 13.1 ± 3.8 mm v 17.3 ± 4.0 mm; S': 6.7 ± 2.1 cm/s v 9.1 ± 2.2 cm/s; both p < 0.001). Neither a modified deep transgastric view (TAPSE 14.5 ± 4.7 mm, p = 0.017; S' 6.8 ± 1.8 cm/s, p < 0.001) nor a transgastric right ventricular inflow view (TAPSE 12.3 ± 4.0 mm, p = 0.001; S' 6.0 ± 1.3 cm/s, p < 0.001) was similar to the AP4C. Speckle tracking TAPSE was unbiased but with high variability (mean bias = -0.3 mm, 95% limits of agreement = -9.1 to 8.4); strain and strain rate were higher in TEE than for TTE (-17.7 ± 3.6 v -12.6 ± 2.1, p < 0.001; -1.0 ± 0.2/s v -0.7 ± 0.1/s, p < 0.001). Right ventricular displacement, velocity, and myocardial deformation measured by TEE versus TTE are different. Neither alternative transesophageal echocardiography views nor speckle tracking-based deformation is promising; TAPSE by speckle tracking is unbiased but imprecise.