Supplementary Material for: Valley index as a predictor of prenatal diagnosis of total anomalous pulmonary venous connection

Introduction: Total anomalous pulmonary venous connection (TAPVC) has a low prenatal diagnostic rate. Therefore, we investigated whether Doppler waveforms with a low pulsatility in the pulmonary veins can indicate fetal TAPVC. Methods: This retrospective study included 16 fetuses with TAPVC, including 10 with complex congenital heart disease and 104 healthy fetuses that underwent fetal echocardiography. Pulmonary venous S and D wave flow velocities and the valley (representing the lowest velocity between the S and D waves) were measured. Valley indices I and II were then calculated as (velocity of valley/ greater of the S and D wave velocities) and (velocity of valley/lesser of the S and D wave velocities), respectively. Results: Supra/infracardiac TAPVC cases exhibited significantly greater valley indices than that of the healthy group. After adjusting for gestational age at fetal echocardiography, valley index I (odds ratio [OR] 7.26, p < 0.01) and II (OR 9.23, p < 0.01) were significant predictors of supra/infracardiac TAPVC. Furthermore, valley indices I and II exhibited a high area under the curve for detecting supra/infracardiac TAPVC, regardless of the presence of pulmonary venous obstruction. Conclusion: The valley index may be a useful tool for the detection of fetal TAPVC.

引言：完全性肺静脉异位连接（Total Anomalous Pulmonary Venous Connection, TAPVC）的产前诊断率较低。为此，本研究探讨肺静脉低搏动性多普勒波形是否可提示胎儿TAPVC。方法：本回顾性研究纳入16例TAPVC胎儿（其中10例合并复杂先天性心脏病）以及104例行胎儿超声心动图检查的健康胎儿。测量肺静脉血流的S波、D波流速及谷值（即S波与D波之间的最低流速）。随后分别计算谷值指数I和II：谷值流速与S、D波中较大流速的比值，以及谷值流速与S、D波中较小流速的比值。结果：心上/心下型TAPVC病例的谷值指数显著高于健康对照组。在校正胎儿超声心动图检查时的孕周后，谷值指数I（比值比[OR]=7.26，p<0.01）与II（OR=9.23，p<0.01）均为心上/心下型TAPVC的显著预测因子。此外，无论是否合并肺静脉梗阻，谷值指数I和II在检测心上/心下型TAPVC时均具有较高的曲线下面积。结论：谷值指数或可成为检测胎儿TAPVC的有效工具。