Abstract 17572: Single-beat 3D Transthoracic Echocardiography Applied to Carcinoid Heart Disease and Pulmonary Arterial Hypertension is Feasible and Accurate for Right Ventricular Volumetric Quantification Compared With MRI, With Incremental Value Over 2D Echocardiography
Introduction: The right ventricle (RV) is a clinically important, complex structure that is challenging to quantify by 2D echocardiography (2DE). Single-beat full volume 3D echocardiography (SB3DE) can acquire large volumes at high volume rates in one cardiac cycle, without stitching artefact. We evaluated the accuracy and reproducibility of SB3DE for quantifying RV volumes in large adult populations of acquired RV pressure- or volume-overload, namely pulmonary arterial hypertension (PAH) and carcinoid heart disease (CHD) respectively.
Methods: One-hundred individuals underwent 2DE, SB3DE and cardiac magnetic resonance imaging (CMRI): 49 patients with PAH, 20 with CHD, 11 with metastatic carcinoid tumor but without CHD, and 20 healthy volunteers. Two operators performed test-retest acquisition and post-processing for inter- and intraobserver variability in 21 subjects.
Results: RV SB3DE was attainable in 96% of cases. Average volume rates were 33 volumes per second (vps) for disease groups and 42 vps for controls. Bland-Altman analysis revealed good agreement for end-diastolic volume (EDV, -2.29 ± 26.8mL) and end-systolic volume (ESV, 5.24 ± 18.6mL) measured by RT3DE and CMRI, with a tendency to underestimate stroke volume (SV, -7.47 ± 23.1mL) and ejection fraction (EF, -4.58 ± 13.6%) by SB3DE. Subgroup analysis demonstrated a bias for volumetric underestimation particularly in control populations (EDV, -11.2 ± 22.1 mL; SV, -11.5 ± 21.1 mL). ROC curve analysis showed that SB3E EF was superior to 2DE parameters for identifying RV dysfunction in PAH (sensitivity 94.1%, specificity 87.5%, AUC 0.949, p<0.001). Coefficients of variation for test-retest reproducibility ranged from 3.1-7.9% for intraobserver and 7.6-16.9% for interobserver variability, with an interobserver bias for volume underestimation (EDV: -12.7 ± 27.0mL; SV: -11.3 ± 23.1mL).
Conclusions: SB3DE is a feasible and accurate technique for RV volumetric quantification in acquired RV pressure- or volume-overload. SB3DE has incremental value over conventional 2DE measures for identifying RV dysfunction. Future work is required to improve upon the underestimation of smaller RV cavity volumes, and the test-retest reproducibility of SB3DE for the serial follow-up of RV volumes.
- © 2013 by American Heart Association, Inc.