When nicotine binds to receptors in the peripheral nervous system, it increases blood pressure, heart rate, cardiac contractility, and gastrointestinal tract activity.

尼古丁在与周围神经系统的受体相结合时，会引起血压升高，心率加快，心肌收缩力增强，胃动增加等。

So, one of the things is they cause our heart to have decreased contractility, because after a heart attack, you've sustained some damage to your heart muscle, so it can't always contract very well.

第是心脏收缩力下降，因为心脏后，心肌受到损害，因此收缩能力下降。

However because calcium is also involved in cardiac myocyte contraction, these agents also reduce contractility of the heart and should not be used in case of systolic heart failures.

然而，因为钙通也参与了心肌收缩，所以这些药物也会减弱心脏的收缩力，因此收缩性心力衰竭患者不应该使用该类药物。

If your heart has decreased contractility then it's going to have to work harder to maintain proper profusion of your body with blood.

如果心脏收缩力下降，那么它将不得不更加努力地维持身体适当的血液灌注。

So how does reduced contractility do that?

那么，收缩力是如何降低的呢？