Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan.
Clinical Laboratory, University of Tsukuba Hospital, Tsukuba, Japan.
J Am Soc Echocardiogr. 2017 May;30(5):461-467. doi: 10.1016/j.echo.2016.12.002. Epub 2017 Jan 5.
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.
Sixty consecutive patients who underwent right-heart catheterization studies were prospectively enrolled. Echocardiography was performed <24 hours before catheterization. From three-dimensional data sets, a cross-section of the IVC was determined that was perpendicular to the long-axis reference of the IVC. Short diameter (SD), long diameter (LD), the ratio of SD to LD (S/L) as the sphericity index, and area were measured on this cross-sectional IVC image.
CVP correlated moderately with SD (r = 0.69, P < .001), strongly with S/L (r = 0.75, P < .001), and modestly with area (r = 0.47, P < .001) but not with LD (r = 0.24, P = .17). The largest areas under the curve by receiver operating characteristic analyses to detect CVP ≥ 10 mm Hg were 0.98 (95% CI, 0.97-1.0; P < .001) for S/L, 0.83 for SD (95% CI, 0.74-0.94; P < .001), and 0.70 for area (95% CI, 0.56-0.84; P = .02). If a cutoff value of 0.69 for S/L was used, the sensitivity, specificity, and accuracy to detect CVP ≥ 10 mm Hg were 0.94, 0.95, and 0.95 and for CVP grading by 2DE were 0.59, 0.98, and 0.85, respectively. Estimations of CVP were more accurately reclassified using S/L rather than grading by 2DE (net reclassification improvement, 0.38; 95% CI, 0.31-0.44; P < .001).
S/L of an IVC cross-section measured using three-dimensional echocardiography may be a reliable parameter to estimate CVP compared with standard grading by 2DE.
下腔静脉（IVC）的长轴图像在通过二维超声心动图（2DE）对中心静脉压（CVP）进行分级时，作为 IVC 形态的替代物存在局限性，因为 IVC 的各种横截面形态以及 IVC 的平移运动由嗅探引起。基于静脉压与顺应性之间的关系，假设使用三维超声心动图获得的 IVC 横截面形态可能比 2DE 标准分级更准确地估计 CVP。
前瞻性纳入 60 例接受右心导管检查的连续患者。在导管检查前 <24 小时进行超声心动图检查。从三维数据集确定与 IVC 长轴参考垂直的 IVC 横截面。在该 IVC 横截面图像上测量短直径（SD）、长直径（LD）、SD 与 LD 的比值（S/L）作为球度指数和面积。
CVP 与 SD 中度相关（r=0.69，P<.001），与 S/L 强相关（r=0.75，P<.001），与面积中度相关（r=0.47，P<.001），但与 LD 不相关（r=0.24，P=0.17）。受试者工作特征分析得到的最大曲线下面积以检测 CVP≥10mmHg 的指标为 S/L（0.98 [95% CI，0.97-1.0；P<.001]）、SD（0.83 [95% CI，0.74-0.94；P<.001]）和面积（0.70 [95% CI，0.56-0.84；P=0.02]）。如果 S/L 的截断值为 0.69，则检测 CVP≥10mmHg 的灵敏度、特异性和准确性分别为 0.94、0.95 和 0.95，而 2DE 分级的灵敏度、特异性和准确性分别为 0.59、0.98 和 0.85。使用 S/L 对 CVP 进行估计的再分类比使用 2DE 分级更准确（净再分类改善，0.38；95%CI，0.31-0.44；P<.001）。
与 2DE 标准分级相比，使用三维超声心动图测量的 IVC 横截面的 S/L 可能是一种可靠的估计 CVP 的参数。
