Assessment of left ventricular outflow tract and aortic root: comparison of 2D and 3D transthoracic echocardiography with multidetector computed tomography

Abstract

Aims Accurate echocardiographic assessment of left ventricular outflow tract (LVOT) and the aortic root is necessary for risk stratification and choice of appropriate treatment in patients with pathologies of the aortic valve and aortic root. Conventional 2D transthoracic echocardiographic (TTE) assessment is based on the assumption of a circular shaped LVOT and aortic root, although previous studies have indicated a more ellipsoid shape. 3D TTE and multidetector computed tomography (MDCT) applies planimetry and are not dependent on geometrical assumptions. The aim was to test accuracy, feasibility, and reproducibility of 3D TTE compared to 2D TTE assessment of LVOT and aortic root areas, with MDCT as reference. Methods and results We examined 51 patients with 2D/3D TTE and MDCT at the same day. All patients were re-examined with 2D/3D TTE on a different day to evaluate 2D and 3D re-test variability. Areas of LVOT, aortic annulus, and sinus were assessed using 2D, 3D TTE, and MDCT. Both 2D/3D TTE underestimated the areas compared to MDCT; however, 3D TTE areas were significantly closer to MDCT-areas. 2D vs. 3D mean MDCT-differences: LVOT 1.61 vs. 1.15 cm2, P = 0.019; aortic annulus 1.96 vs. 1.06 cm2, P < 0.001; aortic sinus 1.66 vs. 1.08 cm2, P = 0.015. Feasibility was 3D 76–79% and 2D 88–90%. LVOT and aortic annulus areas by 3D TTE had lowest variabilities; intraobserver coefficient of variation (CV) 9%, re-test variation CV 18–20%. Conclusion Estimation of LVOT and aortic root areas using 3D TTE is feasible, more precise and more accurate than 2D TTE.

Feasibility and reliability of comprehensive three-dimensional transoesophageal echocardiography screening process for transcatheter mitral valve replacement

“…Despite our data showed a high correlation between the two methods, they also confirmed previous findings regarding the slight tendency of echocardiography to underestimate measurements compared to CT. 22–23 In this regard, 3D-TOE, underestimating and predicting smaller neo-LVOT areas, may theoretically overestimate the risk of LVOTO, causing a possible incorrect exclusion of the patient for ineligibility. Similarly, it can lead to wrongly judge a MA too small for a TMVR.…”

Comparison of Left Ventricular Outflow Tract Diameter Measurements Using Echocardiography in Newborn Infants

“…2 Comparing 2D echocardiography of the LVOT measured at AV hinges with 3D and multidetector computed tomography scans in adults revealed that 2D echocardiography underestimated the diameter measurements. 3 This difference could be attributed to operator dependency associated with 2D echocardiography. The Bland-Altman plot reveals two outliers that might have contributed to the difference in measurements observed in this study.…”