And it begins with pacemaker cells generating their own action potentials.

它始于起搏细胞产生自己的动作电位。

Pacemaker cells operate the same way, except for that initial stimulus. They don't need it.

起搏细胞以同样的方式运作，除了最初的刺激。它们不需要。

After those pacemaker cells make themselves fire, they spread their electrical impulses to cardiac muscle cells throughout the atria.

这些起搏细胞自我激活后，它们将电脉冲传播到整个心房的心肌细胞。

This happens because an abnormal contraction signal, called a depolarization, originates from somewhere in the ventricles rather than coming from the pacemaker cells.

这种情况的发生是因为一次异常的收缩信号，叫做去极化，源于心室某处，而非起搏细胞。

The gene changed heart muscle cells -- called cardiomyocytes -- into natural pacemaker cells.

该基因将心肌细胞（称为心肌细胞）转变为天然起搏细胞。

Researchers in California created what they are calling " biological pacemaker cells" by adding a single gene to a virus.

加利福尼亚州的研究人员通过向病毒添加单个基因创建了他们所谓的“生物起搏器细胞” 。

The pacemaker cells at the start of the conduction system have the leakiest membranes, and therefore the fastest inherent rhythms, so they control the rate of the entire heart.

传导系统开始时的起搏细胞有最容易渗漏的膜，因此固有节律最快，所以它们控制整个心脏的速度。

In the heart, we call this out-of-sync behavior fibrillation, and it can be caused by all sorts of problems, especially ones that affect the pacemaker cells in the SA node.

在心脏，我们称之为不同步行为颤动，它可以由各种问题引起，尤其是那些影响 SA 节点中起搏细胞的问题。

This is because hyperpolarization enhances the funny currents in cardiac pacemaker cells resulting in a faster phase 4 depolarization and thus a faster heart rate.

这是因为超极化会增强心脏起搏细胞中的funny电流，导致更快的4相去极化，从而加快心率。

So pacemaker cells are, in a way, your heart's very own brain, generating the initial spark that sends a current through your heart's internal wiring system, known as the intrinsic cardiac conduction system.

所以起搏细胞在某种程度上是心脏自己的大脑，产生最初的火花，通过心脏的内部线路系统发送电流，被称为内在心脏传导系统。

Now, the interesting thing is that in addition to the pacemaker cells in the SA node, cells in the AV node, Bundle of His, and the Purkinje fibers, all have the ability to generate an electrical potential.

好了，有趣的是除窦房结起搏细胞以外，房室结、希氏束以及浦肯野纤维中的细胞都有形成电势的能力。

When a signal doesn't make it to the ventricles from the atria, and if a long enough time passes by, let's say about 2 seconds, then ventricle's pacemaker cells kick in, sort of as a fail-safe mechanism called a ventricular escape beat.

当一个电信号无法传导至心室，假设延误的时间足够长，比如说长达约2秒，心室起搏细胞便会成为起搏点，这是一种安全保护机制，我们称之为心室逸搏。