Estimation of Central Venous Pressure Using the Ratio of Short to Long Diameter from Cross-Sectional Images of the Inferior Vena Cava

Background Long-axis images of the inferior vena cava (IVC) have limitations as surrogates for IVC morphology in grading central venous pressure (CVP) by two-dimensional echocardiography (2DE), because of the various cross-sectional morphologies and the translational motion of the IVC induced by sniffing. On the basis of the relationship between venous pressure and compliance, it was hypothesized that the cross-sectional morphology of the IVC, which was obtained using three-dimensional echocardiography, might estimate CVP more accurately compared with standard grading by 2DE. Methods Sixty consecutive patients who underwent right-heart catheterization studies were prospectively enrolled. Echocardiography was performed