心肺运动试验中窦房结变时效应频率应答特性的初步探讨

The Study of Chronotropic Responsiveness of Sinus Node to Exercise Testing

采用最大症状限制性心肺运动试验的方法，依据运动过程中心率与机体作功和体内代谢强度的变化关系研究４０名正常人运动中窦房结变时效应的频率应答特性，探讨心率储备和影响最大心率的主要因素。结果显示：心率与作功呈直线相关（Ｙ＝７５＋０．４１Ｘ，ｒ＝０．９８６３，Ｐ＜０．００１）。运动中心率与代谢当量亦呈直线相关（Ｙ＝５２．３＋１１．０１Ｘ，ｒ＝０．９１５２，Ｐ＜０．００１）。影响最大心率的主要因素是氧耗量、二氧化碳量和每分通气量。运动过程中心率与运动负荷和代谢的线性关系反映了窦房结频率应答的特性，即代谢性频率应答。窦房结的这种特性可能是单传感器频率应答性起搏器不能完全符合生理需要的基本原因。

This study was to explore the chronotropic responsiveness of sinus node to workload and METS during cardiopulmanory exercise testing.Forty persons underwent symptomatic limited exercise testing.The relationship between heart rate and METS,heart rate and workload were analyzed with standard linear regression analysis.The major factors which might influnce heart rate were analyzed with multiple linear regression analysis.The results show:(1)There was a highly linear relation between heart rate and workload( Y =75+0.41 X , r =0.9863, P < 0.001) .There was also a linear relation between heart rate and METS( Y =52.3+11.01 X , r =0.9512, P < 0.001 ).The major factors which determined HR max during exercise were V CO 2max ,V O 2max and V E max .The chronotropic response of sinus node to exercise is the rate response which is controlled by metablism during exercise testing.This is the reason why the rate responsive pacemaker by one sensor is not suitable for the physiologic demand completely.