英语语法分析

The drug markedly slowed the heart rate and antagonized the positive chronotropic effect of isoprenaline.

冠益嗪明显减慢大鼠心率，拮抗异丙肾上腺素的正性变时作用。

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

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。

Objective To investigate the change of Chronotropic action and heart rate variability (HRV) in patients with essential hypertension (EH).

目的探讨原发性高血压(EH)患者变时性功能与心率变异性(HRV)的变化。