Fetal and Neonatal Cardiology Program, Division of Cardiology, Department of Pediatrics, Women and Children's Health Research and Mazankowski Alberta Heart Institutes, University of Alberta, Edmonton, AB, Canada.
J Am Soc Echocardiogr. 2012 Oct;25(10):1068-74. doi: 10.1016/j.echo.2012.06.005. Epub 2012 Jul 12.
The systemic right ventricle in palliated hypoplastic left heart syndrome (HLHS) has relatively reduced longitudinal compared with circumferential deformation, a pattern of contraction more akin to the normal left ventricle, which presumably improves right ventricular (RV) pumping efficiency. The aim of this study was to test the hypothesis that these changes in the RV contraction pattern in infants with HLHS are present prenatally.
Echocardiograms from 48 fetuses with HLHS were retrospectively compared with those from appropriately grown RV and left ventricular controls. Ventricular function was assessed using Velocity Vector Imaging velocity, tissue deformation, two-dimensional echocardiography, and Doppler flow parameters.
Fetuses with HLHS demonstrated reduced peak global RV longitudinal velocity (P < .01), strain (P < .001), and displacement (P < .05), while radial displacement was increased (P < .001) compared with the normal fetal right ventricle. Mean RV diameter was increased in HLHS (P < .001), but length was unchanged. The ratio of longitudinal to circumferential deformation was reduced in HLHS compared with the normal right ventricle (P < .001) and equivalent to the normal left ventricle. Tricuspid inflow peak A-wave velocity (P < .01), A-wave duration, A-wave inflow fraction, RV Tei index (P < .05 for all), and inferior vena cava A-wave reversal (P < .0001) were increased in HLHS.
The fetal right ventricle in HLHS becomes more spherical because of increased RV diameter. It has relatively reduced longitudinal compared with circumferential deformation and an increased reliance on atrial contraction for ventricular filling. These findings are similar to postnatal changes observed in the systemic right ventricle in palliated congenital heart disease, suggesting that ventricular remodeling is initiated in fetal life.
在姑息性左心发育不全综合征（HLHS）中，系统右心室的纵向变形相对小于环向变形，收缩模式更类似于正常左心室，这可能会提高右心室（RV）的泵血效率。本研究旨在检验以下假设：HLHS 婴儿的 RV 收缩模式的这些变化在产前就存在。
回顾性比较了 48 例 HLHS 胎儿与适当生长的 RV 和左心室对照组的超声心动图。使用速度向量成像速度、组织变形、二维超声心动图和多普勒血流参数评估心室功能。
与正常胎儿右心室相比，HLHS 胎儿的峰值整体 RV 纵向速度（P <.01）、应变（P <.001）和位移（P <.05）降低，而径向位移增加（P <.001）。HLHS 中 RV 平均直径增加（P <.001），但长度不变。与正常右心室相比，HLHS 的纵向与环向变形比降低（P <.001），与正常左心室相当。与正常右心室相比，HLHS 的三尖瓣流入峰值 A 波速度（P <.01）、A 波持续时间、A 波流入分数、RV Tei 指数（所有 P <.05）和下腔静脉 A 波反转（P <.0001）增加。
由于 RV 直径增加，HLHS 中的胎儿右心室变得更加球形。它的纵向变形相对小于环向变形，并且对心房收缩的依赖增加，以填充心室。这些发现与姑息性先天性心脏病中系统右心室的产后变化相似，表明心室重构始于胎儿期。
