Fetal Heart Program, Division of Cardiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229, USA.
J Am Soc Echocardiogr. 2011 Aug;24(8):834-40. doi: 10.1016/j.echo.2011.04.010. Epub 2011 Jun 8.
Twin-twin transfusion syndrome (TTTS) complicates 10% to 15% of monochorionic twin pregnancies. Cardiovascular changes of variable severity, such as ventricular hypertrophy, atrioventricular valve regurgitation, and systolic dysfunction, occur predominantly in recipient twins (RTs). It was the purpose of this study to perform a detailed assessment of ventricular geometry and diastolic function between controls, donor twins (DTs), and RTs.
In this prospective, case-control study, two-dimensional, pulsed-wave, and Doppler tissue imaging were used to evaluate biventricular geometry and diastolic function in controls, DTs, and RTs. RTs were divided into two groups, severe and mild, on the basis of evidence of high central venous pressure. Specific variables evaluated included relative wall thickness, mitral valve and tricuspid valve E/A velocities, diastolic filling time corrected for heart rate, isovolumic relaxation time, and early (E') and late (A') diastolic myocardial velocities.
A total of 120 fetuses (39 TTTS twin pairs and 42 controls) were compared. Increases in relative wall thickness and isovolumic relaxation time were seen in the mild group. In the severe group, further increases in relative wall thickness and isovolumic relaxation time as well as decreased diastolic filling time corrected for heart rate were accompanied by the appearance of a monophasic Doppler inflow profile and elevations in the E/E' ratio, consistent with elevated ventricular filling pressures.
Concentric hypertrophy is observed in RTs affected by TTTS and is associated with impaired ventricular relaxation and shortened filling time. In severe cases, further decreases in diastolic filling time and Doppler signs of elevated ventricular filling pressures are present.
双胎输血综合征（TTTS）在 10%-15%的单绒毛膜性双胎妊娠中发生。心室肥厚、房室瓣反流和收缩功能障碍等不同严重程度的心血管变化主要发生在受血儿（RT）中。本研究旨在详细评估对照组、供体儿（DT）和 RT 的心室几何形状和舒张功能。
在这项前瞻性病例对照研究中，我们使用二维、脉冲波和多普勒组织成像来评估对照组、DT 和 RT 的双心室几何形状和舒张功能。根据中心静脉压升高的证据，RT 被分为严重和轻度两组。评估的特定变量包括相对壁厚度、二尖瓣和三尖瓣 E/A 速度、心率校正的舒张填充时间、等容舒张时间以及早期（E'）和晚期（A'）舒张心肌速度。
共比较了 120 个胎儿（39 对 TTTS 双胞胎和 42 个对照组）。在轻度组中，相对壁厚度和等容舒张时间增加。在重度组中，进一步增加的相对壁厚度和等容舒张时间以及心率校正的舒张填充时间缩短，同时出现单相多普勒流入轮廓和 E/E'比值升高，提示心室充盈压升高。
受 TTTS 影响的 RT 中观察到向心性肥厚，与心室舒张功能障碍和充盈时间缩短有关。在严重的情况下，进一步降低的舒张填充时间和多普勒提示升高的心室充盈压。
