This is the term used to describe the contraction of the heart.

这是用来描述脏收术语。

This is a term used to describe the contraction of the heart.

这是一个用来描述脏收术语。

That is reassuring. But what about the other bad beats, the premature contractions in the heart's lower chambers?

这就让人。那其他有害跳，发生在脏下期前收(室性期前收)呢?

On rare occasions, a sudden change in heart rhythm prevents the upper chambers of the heart from contracting normally.

在极少数情况下，律突然变化会阻止脏上常收。

Frank and Starling were looking at the amount of blood in the heart before the ventricles contract.

Frank 和Starling在观察室收前脏血流量。

It would squeeze the capsule tightly as the heart contracted and still keep a firm grip on it when the heart was relaxed.

它可以随着脏收轻微挤压胶囊，且在脏松时，也能紧紧抓住。

This ability is thanks to the intrinsic conduction system, which is the internal regulating system that causes the heart to contract rhythmically.

这种能力是由于内在传导系统，这是导致脏有节奏收内部调节系统。

This ability is thanks to the intrinsic conduction system, which is defined as the internal regulating system that causes the heart to contract rhythmically.

这种能力归功于内在传导系统，内在传导系统被定义为使脏有节奏地收内部调节系统。

That's right - a healthy heart does not pump every last drop of blood out of the ventricles when they contract no matter how strongly they contract.

没错，一个健康脏在收时候不会把每一滴血从室中泵出，不管收多厉害。

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，因为钙通道也参与肌收，所以这些药物也会减弱脏收力，因此收性力衰竭患者不应该使用该类药物。