Typically treatment for premature atrial contractions isn't required.

通常房性期前收缩并不需要治疗。

They were measuring two things: the number of what are called premature atrial contractions and premature ventricular contractions.

房性早搏和室性早搏的数量。

This is what leads to a premature ventricular contraction, or PVC.

这就导致了一次室性期前收缩，或者说PVC。

These circuits can be initiated by several mechanisms, like premature contractions in the atria or ventricles.

这些折返通路可能由好几个机制所引起，比如心房或心室的提前收缩。

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

那么其它不良搏动，也就是心脏下室的早搏呢？

For example, ventricular bigeminy is when a premature ventricular contraction consistently comes after each normal cardiac cycle.

比如，室性二联律就是室性期前收缩在每个正常心动周期之后持续发生。

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

这就让人放心了。那其他有害心跳，发生在心脏下腔的期前收缩(室性期前收缩)呢?

They found that drinking coffee did not result in more premature atrial contractions — the early heart beats associated with atrial fibrillation.

他们发现，喝咖啡并没有导致更多的房性早搏——与房颤相关的心脏过早搏动。

Regardless of the originating ventricle, a premature ventricular contraction often has an abnormal T wave since the timing and direction of repolarization will be abnormal as well.

不论起源心室是哪个，室性期前收缩由于去极化的时程和方向也会异常，而经常有一个异常的T波。

It's very common for everyone to have an early beat arising from the upper chambers of the heart called premature atrial contractions, or PACs, once in a while.

每个人的上心室偶尔都会出现早搏即房性早搏（PACs），这是非常常见的。