Another type of atrial ectopic focus is a reentrant loop, which is when there's some tissue that doesn't depolarize right.

另一类房性异位起搏点是一个折返环路，主要发生在当某些组织不能正确地除极的时候。

This reduces the heart's excitability and suppresses reentrant tachycardia.

这降低心脏的兴奋性和抑制折返性快速性心律失常。

This reduced conduction velocity helps to suppress formation of reentrant circuits.

这种减慢的传导速度有助于抑制折返环的形成。

Hence the use of these drugs for treating reentrant tachycardia x'.

因此这些药物可用于治疗折返性心动过速。

A reentrant loop basically starts sending out depolarization waves to the rest of the heart tissue each time the wave goes around.

每沿着折返环路环绕一圈，它就开始向其余心肌组织发放除极波。

So, in short, a particularly stressed out atrial cell or a reentrant loop can send out depolarization waves that contract the atria, and result in an early, or premature, atrial contraction.

因此，简单说就是一个尤其应激的心房细胞、或者一个折返环路发放除极波导致心房收缩，造成早期或过早的心房收缩。

This type where it goes up from ventricle to atrium, is called Atrioventricular reentrant tachycardia (or AVRT) with orthodromic conduction, and can lead to very high ventricular rates, between 200 and 300 bpm.

这种电冲动从心室传导到心房的类型，称为顺向传导的房室折返性心动过速（AVRT）；它可以导致很快的心室率，达到每分钟200-300次。