慢性肺心病左右心室改变及其与高CO_2的关系

Experimental study of left and right ventricular changes and the role of hypercapnia in chronic cor pulmonale.

目的研究慢性肺心病左右心室改变的特点及其与高二氧化碳存在的关系。方法通过复制慢性缺氧性及慢性缺氧高二氧化碳性肺心病模型，观察单纯缺氧四周，缺氧高二氧化碳二周及四周，正常对照组大鼠，肺动脉压，右心室压力及右心室最大压力上升和下降速度，右室重量（ＲＶ）和左室加室间隔重量（ＬＶ＋Ｓ），并分析左右心室重量的相关性。结果缺氧四周及缺氧高二氧化碳二周和四周均引起明显肺动脉高压和右室收缩压升高，其程度相似。缺氧四周时心脏仅表现右室肥厚，缺氧高二氧化碳四周时右室肥厚更明显，并出现左室肥厚。缺氧高二氧化碳组左右心室重量之间相关性良好，而缺氧组两者无相关性。结论高二氧化碳加重缺氧引起的肺心病右室肥厚，并引起左室肥厚，左右心室肥厚非解剖因素相互作用所致。

Objective To study the feature of changes in left and right ventricular in chronic cor pulmonale and the correlation between the changes and the role of hypercapnia.Methods By creating the models of chronic hypoxic cor pulmonale and hypoxic hypercapnic cor pulmonale,the pulmonary artery pressure(PAP),right ventricular systolic pressure(RVSP),RV + -dp/dtmax and heart rate in rats exposed to 4 weeks hypoxia and 2 or 4 weeks hypoxia hypercapnia respectively were examined.Right ventricular(RV) and left ventricular plus septum(LV+S) were weighed in those rats,and relationship between RV/100gBW and LV+S/100gBW in each group was analyzed.Results Pulmonary hypertension developed in rats exposed to 4 weeks hypoxia(H) and 2 or 4 weeks hypoxia hypercapnia(HH) and they had higher RVSP compared to normal control,but no significant difference was found in PAP and RVSP between those groups.Rats exposed to 4 weeks hypoxia had right ventricular hypertrophy(RVH) only,but rats exposed to 4 weeks HH had left ventricular hypertrophy and more marked RVH compared to 4 weeks H.There were significant correlations between RV/100gBW and LV+S/100gBW in the 2 and 4 weeks HH groups,but no significant correlation between those in H group.Conclusion Hypercapnia increased the RVH and induced the left ventricular hypertrophy in hypoxic cor pulmonale.The left and right ventricular hypertrophy developed independently,not through ventricular interdependence.