变时作用

结论：GST对家兔窦房结具有负性变时作用，并可延长复极化时程。

CONCLUSION : GST exerted a negative chronotropic action and induced a delayed repolarization of pacemaker cells in SA nodes of rabbits .

异钩藤碱在未影响大鼠血压时即可产生负性变时作用，该效应与心肌M，β和H2受体无关，似与其抗Ca~（2+）作用有关。

Isorhynchophylline ( 2 ~ 4mg / kg iv ) can produce a negative chronotropic effect in rats without influencing blood pressure . This negative chronotropic effect has nothing to do with cardiac M , β and H_2 receptors , but may be related to the block of calcium .

高钙对兔窦房结的负性变时作用

Negative chronotropic effect of calcium on the sinus node of rabbits

异钩藤碱的负性变时作用及其机理的探讨

The Negative Chronotropic Effect of Isorhynchophylline and Its Mechanism

具有良好变时作用的持续性房性异位心律：临床特征、电生理机制及射频导管消融

Sustained ectopic atrial rhythm with sufficient chronotropic function : clinical characteristics , electrophysiologic mechanisms and its radiofrequency catheter ablation

结论：①下丘脑TRH对心脏有正性变时、变力作用。

Conclusion : ① Hypothalamic TRH can produce positive inotropic and chronotropic response to myocardium .

结论：内源性儿茶酚胺介导了IL2的致离体心脏心律失常、正性变时和变力作用，较高浓度的IL2抑制离体心脏的功能。

Conclusion : Endogenous catecholamine mediates the arrhythmogenic , positively chronotropic and inotropic effects of IL-2.IL-2 at 200 U / ml inhibits the cardiac function in the isolated rat heart .

结论高浓度川芎水煎剂对离体大鼠心脏有负性变力和负性变时作用，并可使CF降低；

CONCLUSION The results indicated that LCH decoction of high concentration has obvious negative inotropic action and can increase CF obviously ;