上腔静脉频谱在评价常压低氧致大鼠肺高压中的应用

Application of superior vena cava Doppler spectra in evaluation of atmospheric hypoxia-induced pulmonary hypertension in rats

目的探讨上腔静脉(SVC)频谱在评价常压低氧所致大鼠肺高压(PH)中的应用价值。方法将18只健康成年雄性SD大鼠随机分为PH组(n=12)和对照组(n=6),PH组采用常压低氧法建立动物模型。对两组大鼠进行超声检查,测量肺动脉内径(PAD)和肺动脉峰值流速(PAV_(max))、三尖瓣E峰峰值流速(TVE_(max))、S波流速(S)、D波流速(D)、AR波流速(AR),并计算AR/S和AR/D;采用右心导管测量右心房压力(RAP)、右心室收缩压(RVSP),肺动脉收缩压(PASP)、肺动脉平均压(PAMP);取血测量血清NO含量。处死大鼠后取心脏测量右心室肥厚指数,取肺组织进行病理学检查。结果与对照组比较,PH组RAP、RVSP、PASP、PAMP增高,S波、D波速度减低,AR/D及AR/S升高,差异均有统计学意义(P均<0.05)。RVSP与AR/S、AR/D呈中等和极强相关(r=0.494,P<0.05;r=0.830,P<0.001),PAMP与AR/D呈强相关(r=0.725,P<0.01),与AR/S无相关性(r=0.517,P=0.07)。PH组大鼠肺小动脉出现不同程度内中膜增厚,管腔变小,平滑肌增生。两组右心室肥厚指数、体质量及NO含量差异无统计学意义(P均>0.05)。结论 PH时SVC频谱表现为S波、D波降低,AR/S、AR/D增大,且与肺动脉压力密切相关,可作为多普勒超声评价PH的指标。

Objective To explore the value of superior vena cava （SVC） Doppler spectrum in evaluation of atmospheric hypoxia-indueed pulmonary hypertension （PH） in rats. Methods Totally 18 adult male SD rats were randomized into PH group （n=12） and control group （n=6）. The rats in PH group were exposed to atmospheric hypoxia cabin to make PH models. Ultrasounds were performed in all the rats to measure pulmonary artery diameter （PAD） and peak flow velocity of the pulmonary artery （PAVmax）, E velocity of tricuspid flow （TVEmax）, velocity of S wave （S）, D wave （D）, AR wave （AR） and calculating the ratio of AR/S, AR/D. Right heart catheterization was used to measure right atrial pressure （RAP）, right ventricular systolic pressure （RVSP）, pulmonary artery systolic pressure （PASP）, and pulmonary artery mean pressure （PAMP）. Subsequently nitric oxide （NO） content in serum was detected. Then the rats were sacrificed to measure right ventrieular hypertrophy index and perform HE staining of lung tissues. Results The value of RAP, RVSP, PASP in PH group were higher than those of control group, and the differences were significant （all P〈0.05）. The S and D velocity significantly decreased and AR/S, AR/D ratio were statistically significant higher in PH groups than those in control group （all P〈0.05）. RVSP were moderately and extremly strongly correlated with AR/S and AR/D ratio respec- tively （r=0. 494, P〈0.05; r=0. 830, P〈0. 001）. PAMP was strongly correlated with AR/D ratio （r=0. 725, P〈 0.01）. The correlation between PAMP and AR/S had no statistical significance （r=0. 517, P=0. 07）. PH group demon- strated various degrees of pulmonary arterial wall thickening and smooth muscle hyperplasia. The right ventricular hyper- trophy index and NO content had no statistically significant differences between both groups. Conclusion The SVC spec- trum shows that S, D wave decrease, AR/S, AR/D ratio increase in PH, which are closely correlated to pulmonary artery pressure. So the SVC spectrum can be used to evaluate PH.