Fetal and Neonatal Cardiology Program, Echocardiography Laboratory, Division of Cardiology, Department of Pediatrics, Women and Children's Health Research, Mazankowski Alberta Heart Institute, and Cardiovascular Research Centre, University of Alberta, Edmonton, Alberta, Canada.
Fetal and Neonatal Cardiology Program, Echocardiography Laboratory, Division of Cardiology, Department of Pediatrics, Women and Children's Health Research, Mazankowski Alberta Heart Institute, and Cardiovascular Research Centre, University of Alberta, Edmonton, Alberta, Canada; Department of Obstetrics and Gynecology, Women and Children's Health Research, Mazankowski Alberta Heart Institutes, and Cardiovascular Research Centre, University of Alberta, Edmonton, Alberta, Canada.
J Am Soc Echocardiogr. 2024 Nov;37(11):1062-1072. doi: 10.1016/j.echo.2024.06.020. Epub 2024 Jul 10.
The perinatal transition is characterized by acute changes in cardiac loading. Compared with normal newborn combined cardiac output (CCO), single right ventricular (RV) output of neonates with hypoplastic left heart syndrome (HLHS) is markedly greater. The aim of this study was to examine the mechanisms of cardiac adaptation that facilitate this perinatal transition from late fetal to early neonatal life in HLHS.
Prospectively recruited pregnancies complicated by fetal HLHS (n = 35) and healthy control subjects (Ctrl; n = 17) underwent serial echocardiography in late gestation (38 ± 1 weeks) and 6, 24, and 48 hours after birth. Cardiac function was assessed using conventional, Doppler tissue, and speckle-tracking echocardiography.
Term fetuses with HLHS had RV output comparable with Ctrl CCO via higher stroke volume. Compared with both left ventricular and RV indices of Ctrl, they exhibited globular and dilated right ventricles with reduced relative wall thickness (0.40 ± 0.08 vs 0.49 ± 0.10, P < .01), increased Tei index' (HLHS vs Ctrl left ventricle/Ctrl right ventricle: sphericity index, 0.9 ± 0.25 vs 0.5 ± 0.10/0.6 ± 0.11; RV area index, 28 ± 6 vs 15 ± 3/17 ± 5 cm/m; Tei index', 0.65 ± 0.11 vs 0.43 ± 0.07/0.45 ± 0.09; P < .0001 for all). Neonates with HLHS generated elevated RV cardiac output compared with Ctrl CCO via higher heart rate and stroke volume, with further RV dilatation, increased longitudinal systolic strain at 48 hours (-17 ± 4% vs -14 ± 3%/ 14 ± 5%) with reduced circumferential and rotational myocardial deformation and altered diastolic function. Neonates with HLHS also demonstrated right atrial enlargement with increased longitudinal strain: 6 hours (33 ± 12% vs 26 ± 6%), 24 hours (37 ± 15% vs 26 ± 13%), and 48 hours (38 ± 11% vs 24 ± 13%) (P < .0001).
Term fetuses with HLHS exhibit altered RV geometry and RV systolic and diastolic functional parameters. After birth, further alterations in these cardiac parameters likely reflect adaptation to acutely altered RV loading from increasing cardiac output and pulmonary artery flow demands.
围产期过渡的特点是心脏负荷的急剧变化。与正常新生儿的全心输出量（CCO）相比，左心发育不全综合征（HLHS）新生儿的单右心室（RV）输出量明显增加。本研究的目的是探讨心脏适应的机制，以促进 HLHS 从胎儿晚期到新生儿早期的这种围产期过渡。
前瞻性招募患有胎儿 HLHS（n=35）和健康对照组（Ctrl；n=17）的妊娠妇女，在妊娠晚期（38±1 周）和出生后 6、24 和 48 小时进行多次超声心动图检查。使用常规、多普勒组织和斑点追踪超声心动图评估心功能。
足月胎儿 HLHS 通过更高的每搏量使 RV 输出量与 Ctrl CCO 相当。与左心室和 RV 指数的 Ctrl 相比，它们表现出球形和扩张的右心室，相对壁厚度降低（0.40±0.08 与 0.49±0.10，P<.01），Tei 指数增加（HLHS 与 Ctrl 左心室/Ctrl 右心室：球形指数，0.9±0.25 与 0.5±0.10/0.6±0.11；RV 面积指数，28±6 与 15±3/17±5cm/m；Tei 指数'，0.65±0.11 与 0.43±0.07/0.45±0.09；P<.0001 均为）。HLHS 新生儿与 Ctrl CCO 相比，通过更高的心率和每搏量产生更高的 RV 心输出量，进一步 RV 扩张，48 小时时纵向收缩应变增加（-17±4%与-14±3%/14±5%），圆周和旋转心肌变形减少，舒张功能改变。HLHS 新生儿还表现出右心房扩大，纵向应变增加：6 小时（33±12%与 26±6%），24 小时（37±15%与 26±13%），48 小时（38±11%与 24±13%）（P<.0001）。
足月胎儿 HLHS 表现出 RV 几何形状和 RV 收缩和舒张功能参数的改变。出生后，这些心脏参数的进一步改变可能反映了从增加的心输出量和肺动脉流量需求中急性改变 RV 负荷的适应性。
