T-E_(max)及dP/dt_(max)评定主动脉内气囊反搏对心肌收缩性能影响的比较

Effects of Intra-aortic Balloon Pump (IABP) on Myocardial Contractility Assessed by T-E_(max) and dP/dt_(max)

应用瞬时收缩末压力—容积线的斜率T-E_(max),与左心室内压发展最人速率dP/dt_(max)进行比较,评价了主动脉内气囊反搏(IABP)对10只狗在体正常及局部缺血心脏心肌收缩性能的影响。T-E_(max)在正常心脏进行IABP时无显著变化(1.97±0.53 vs,1.97±0.56kPa/ml,P>0.05),在缺血心脏进行IABP时显著增加(1.20±0.35 vs 1.41±0.32,P<0.01);而dP/dt_(max),无论在正常(611.85±146.63 vs 503.74±113.70kPa/s,P<0.01)或缺血(336.45±69.54 vs 303.66±70.52,P<0.05)心脏进行IABP时均显著减小。结果表明:IABP对心肌收缩性能的影响与心脏的基础状态有较大关系,IABP仅对缺血心脏有增加心肌收缩性能的作用。T-E_(max)能较恰当地评价狗在体心脏的心肌收缩性能状态,而dP/dt_(max)则有可能低估IABP对心肌收缩性能的影响。

The effects of IABP on myocardial contractility assessed by the transient slope of the end-systolic pressure-volume line (T-E_(max)) and the maximum rate of rise of the left ventricular pressure (dP/dt_(max)) were studied in 10 dogs.T-E_(max) was little changed in the normal heart (1.97 ± 0.53 kPa/ml vs 1.97 ± 0.56,P>0.05), but was significantly increased in the regional ischemic heart (1.20 ± 0.35 vs 1.41 ± t 0.32,P<0.01) during IABP.On the contrary,dP/dt_(max) decreased during IABP in both normal (611.85 ± 146,63 kPa/s vs 503.74 ± 113.70, P<0.01) and the regional ischemic heart (310.92±79.38 vs 281.89 ± 67.08, P<0.05). The results are consistent with the predictions of the beneficial effects of IABP on myocardial contractility merely in regional ischemic heart, supporting the use of T-E_(max) for the assessment of myocardial contractile state of the in situ dog heart instead of dP/dt_(max) which may underestimates the myocardial contractility during IABP.