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目的探讨急进高原适应过程中肺动脉压力的动态变化及可能机制及对右室功能的影响。方法 62名健康汉族男性青年,分别在平原(海拔390m)空运至西藏拉萨(海拔3 658m)后第1 d、第7 d、第60 d接受了多普勒超声测量主肺动脉血流加速时间(ACT)、右心室射血时间(RVET)、右室射血前期(RVPEP)、右室流出道宽度(ROVT)、主肺动脉内径(MPAD)、右室舒张末期内径(RVD)。硝酸还原法测定相同时间点的血清一氧化氮(NO),放射免疫法检测血清内皮素(ET-1)的水平。结果与平原比较,急进高原第1 d收缩期肺动脉压(SPAP)、平均肺动脉压(m PAP)和E/A值明显升高(P<0.05),ROVT明显降低(P<0.05),ET-1明显升高(P<0.05)。急进高原第7 d SPAP、m PAP和ROVT明显降低(P<0.05),NO和E/A明显增高(P<0.05),急进高原第60 d SPAP、m PAP、ROVT和E/A值明显升高,差异有统计学意义(P<0.05),急进高原第60 d NO及ET-1差异均无统计学意义。与急进高原第1 d比较,急进高原第7 d SPAP、MPAP,ET-1明显增高(P<0.05),NO明显降低(P<0.05),急进高原60 d SPAP、MPAP、POVT和E/A明显升高(P<0.05),ET-1、NO变化不显著。与急进高原第7 d比较,急进高原60 d SPAP、MPAP明显升高(P<0.05),ET-1、NO变化不显著。结论缺氧、低压的高原环境导致了肺动脉压力增高,但在急进高原初期适应过程中,肺动脉压力出现一过性降低(急进高原第7 d)、右心舒张功能增强的波动,这一变化可能与NO及ET-1在不同时向交替占优势、调节肺血管的收缩舒张有关。
Objective To investigate the dynamic changes of pulmonary artery pressure during acute altitude plateau adaptation and its possible mechanism and its influence on right ventricular function. Methods Sixty-two healthy Han male youths underwent Doppler ultrasound to measure the main pulmonary artery blood flow acceleration time (days 1, ACT, RVET, RVPEP, ROVT, MPAD, and RVD. Nitric acid reduction method was used to determine serum nitric oxide (NO) at the same time point. The level of endothelin (ET-1) was measured by radioimmunoassay. Results Compared with the plain, the pulmonary arterial pressure (SPAP), mean pulmonary arterial pressure (PAPP) and E / A of systolic phase on the first day were significantly increased (P <0.05) and ROVT was significantly decreased 1 was significantly higher (P <0.05). The levels of SPAP, m PAP and ROVT were significantly decreased (P <0.05) and NO and E / A significantly increased on the 7th day (P <0.05), and the SPAP, m PAP, ROVT and E / (P <0.05). There was no significant difference of NO and ET-1 on the 60th day in rapid plateau. The levels of SPAP, MPAP and ET-1 on the 7th day were significantly higher (P <0.05), the NO was significantly lower (P <0.05) on the seventh day than the steep plateau, the SPAP, MPAP, POVT and E / A (P <0.05), ET-1, NO changes were not significant. Compared with the 7th day in the steep plateau, the SPAP and MPAP in the acute plateau increased significantly on the 60th day (P <0.05), and the changes of ET-1 and NO were not significant. Conclusions Hypoxia and low pressure environment lead to the increase of pulmonary artery pressure. However, during the initial stage of rapid plateau adaptation, there is a transient decrease of pulmonary artery pressure (on the 7th day in acute plateau) and the increase of right ventricular diastolic function. This change may be And NO and ET-1 at different times to alternate dominant, regulating pulmonary vasoconstriction related to relaxation.