实时三维超声心动图检测急性和慢性压力负荷升高状态下右心室节段收缩功能的变化特征

Right ventricular (RV) acute or chronic pressure overload (aPO or cPO)can be caused by a variaty of cardiovascular diseases,including acute pulmonary emlolism and chronic pulmonary hypertension. RV function plays an important role in the diagnosis and severity assessment of the underlying diseases. However, current opinions about the characteristic features of RV regional systolic function under aPO or cPO are controversial. RT3DE is a well－developed echocardiographic technique with the advantage of displaying the 3-dimensional anatomy of RV in spite of its irregular chamber shape. This advantage makes it superior to conventional 2-dimensional method in RV function assessment.Recent research demonstrated that RV regional systolic function can be effectively evaluated by RT3DE. In our pilot studies, we found that RV regional systolic function measured by RT3DE was impaired in patients with cPO, and RT3DE parameters concerining RV regional systolic function were strongly correlated with RV afterload, but the relationship between 2-dimensinoal echocardiographic parameters and RV afterload was weak or not significant. The feasibility and reproducibility of RT3DE was good in our clinical an experimental studies.Based on the above facts, our hypothesis is that RT3DE might play a potential role in the evaluation of the characteristic features of RV regional systolic function under aPO and cPO. Therefore we apply for the approval of this present study, aiming to: ① assess the correlation between RT3DE parameters and pathological examination in addition to the correlation between RT3DE and MRI parameters in aPO and cPO canine models, ② explore the relationship between RT3DE parameters and pulmonary embolism index in patients with acute pulmonary embolism as well as the relationship between RT3DE parameters and pulmonary artery resistance derived by right heart catheterization in patients with chronic pulmonary hypertension, ③ recording the changes of RT3DE parameters during follow-up. The results of this present study might provide helpful information for the differential diagnosis and severity assessment of the underlying diseases with the right ventricle under aPO or cPO.

多种心血管疾病可导致右心室急性或慢性压力负荷升高（aPO或cPO），右心室功能与其鉴别诊断和病情评估密切相关，但两种状态下右心室节段收缩功能变化特征目前存在争议。新近研究显示实时三维超声心动图(RT3DE)能有效评价右心室节段收缩功能，我们的前期研究显示cPO患者出现右心室节段收缩功能改变，RT3DE节段收缩功能指标与右心室后负荷间的相关性强于二维超声指标，RT3DE在cPO患者及动物模型中有较高的可行性和重复性。因此我们拟使用RT3DE技术评价右心室节段收缩功能在aPO和cPO两种状态下的不同特征，在比格犬aPO和cPO模型中探索RT3DE参数与磁共振测量值及右心室节段心肌组织病理改变的一致性，在急性肺栓塞和慢性肺高压患者中分析RT3DE参数与肺动脉栓塞指数及右心导管测定的肺阻力的相关性和在长期随访中的变化趋势，旨在为右心室aPO和cPO两种状态的鉴别诊断及病情评估提供新的无创性指标。

临床上多种心血管疾病可导致右心室急性或慢性压力负荷升高，慢性压力负荷升高最常见于多种病因所导致的肺高压（PH）。右心室功能与压力负荷升高相关疾病的病因诊断、治疗方法选择和预后密切相关。本课题的主要研究内容为使用实时三维超声心动图（RT3DE）技术评价右心室节段收缩功能在压力负荷升高状态下的不同特征。.目前在动物实验和临床试验两个方面已完成以下研究内容：（1）入选行心脏磁共振（CMR）检查的PH患者15例。(2）在6只比格犬中通过右房注射野百合碱建立肺高压动物模型，与基线状态、术后即刻、术后1月、术后4月进行RT3DE及常规超声心动图图像采集及右心导管数据。（3）入选各种病因导致的慢性PH患者167例，完成81例房缺相关慢性PH患者封堵术前及术后1天及1月、3月、6月随访，完成34例特发性PAH患者51±18个月随访。.主要研究结果如下：（1）RT3DE测量右心室容积及收缩功能有较高的准确性和一致性，RT3DE测定收缩功能参数对容量负荷的依赖性低于二维超声参数。（2）术后2月比格犬动物模型导管测量的肺动脉压力升高，术后4月右心室心尖部节段EF减低。（3）在相同后负荷状态下，特发性PAH患者右室整体及节段功能低于先心相关的PAH患者（P<0.05），无分流性PAH右室整体与节段收缩功能与右心导管测定的肺血管阻力负相关程度高于有分流存在的PAH患者。特发性PAH患者1年、3年、5年的生存率分别为94.1%，85.3%及72.0%，右室整体EF<30%预示着预后不良。（5）ASD相关PH患者右心室节段收缩功能显著减低、体部节段占右心室整体容积的百分比显著增加（P<0.05），其右心室整体及节段收缩功能与后负荷负相关（r = -0.521 ~ -0.716, P均<0.05）。ASD封堵前后体部节段占右心室整体容积的百分比高于正常对照（P<0.05），以71ml 和 28%为临界值右心室体部节段容积及节段容积百分比能预测封堵术后6月持续性PH。.以上研究结果有望为右心室压力负荷升高状态的鉴别诊断及病情评估提供新的无创性指标，为其他病理生理状态下右心室功能评价提供研究基础和新思路。