Background

Tricuspid regurgitation (TR) is an important risk factor for morbidity and mortality in hypoplastic left heart syndrome (HLHS), yet the evolution of tricuspid valve (TV) dysfunction in HLHS is poorly understood. This study sought to examine changes in TV function in HLHS between the first two stages of surgical palliation and to determine the mechanism of TR at the time of stage two surgery—bidirectional cavopulmonary anastomosis (BCPA).

Methods

We prospectively investigated 44 infants at two time points—prior to Norwood-Sano (T1 - median age 5.4 days) and prior to BCPA (T2 - median age 4.7 months) using two-dimensional (2DE) and three-dimensional echocardiography (3DE). Right ventricular (RV) size, function and shape was assessed with 2DE. Extracted spatial coordinates from 3DE were used to calculate TV leaflet and annular area, tethering and prolapse volumes, bending angle, and coaptation index. TR was graded qualitatively, and 2D and 3D vena contracta (VC) were measured.

Results

The cohort from T1 to T2 had increased indexed leaflet and annular area (P < .0001) and tethering volume (P < .0001), with no change in coaptation. Significant TR was present in 14 infants (32%) at T2 and was associated with greater leaflet (P = .02) and annular areas (P = .002) and greater prolapse volume (P = .008), but not tethering volume or reduced coaptation. At latest follow-up (median 23 months), 13 patients died or required transplantation. Only 3DE VC at T2 was associated with death or transplantation.

Conclusions

The TV in HLHS adapts to interstage stressors (increased preload and afterload) by increasing leaflet size to maintain adequate leaflet coaptation. Significant TR at T2 was associated with greater leaflet size and prolapse. This may represent TV maladaptation from an excessive response in leaflet expansion to stressors.

中文翻译：

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发育不良左心综合征的第一阶段间期三尖瓣适应。

背景

三尖瓣关闭不全（TR）是增生性左心综合征（HLHS）发病率和死亡率的重要危险因素，但对HLHS中三尖瓣（TV）功能障碍的演变了解甚少。这项研究试图检查在手术缓解的前两个阶段之间HLHS中电视功能的变化，并确定在第二阶段手术（双向腔肺吻合术（BCPA））时TR的机制。

方法

我们使用二维（2DE）和三维超声心动图（3DE）在两个时间点（Norwood-Sano之前（T1-中位年龄5.4天）和BCPA之前（T2-中位年龄4.7个月））对44个婴儿进行了前瞻性调查。 。用2DE评估右心室（RV）的大小，功能和形状。从3DE中提取的空间坐标用于计算电视宣传单张和环形区域，系留量和脱垂量，弯曲角度和接合指数。对TR进行定性分级，并测量2D和3D腔静脉收缩（VC）。

结果

从T1到T2的队列增加了索引的小叶和环形区域（P  <.0001）和束缚量（P  <.0001），而配合没有变化。T2时有14例婴儿（32％）出现明显的TR，与更大的小叶（P  = .02）和环形区域（P  = .002）和更大的脱垂量（P  = .008）相关，但与栓系量无关减少适应。在最近的随访中（中位23个月），有13例患者死亡或需要移植。T2时只有3DE VC与死亡或移植相关。

结论

HLHS中的电视通过增加小叶大小以保持适当的小叶适应，从而适应阶段间的压力源（增加了前负荷和后负荷）。T2的TR值显着增加与小叶大小和脱垂有关。这可能是由于瓣叶扩张对应激源的过度反应导致电视适应不良。