It's pushed up into the heart

导管一直向上伸至心脏
and then there are recording electrodes on the end

在其末端有记录的电极
and they can measure electrical activity directly

电极可以直接检测
in the heart at different locations.

心脏不同部位的心电活动
That's called cardiac catheterization and cardiac electrophysiology,

这就是心导管置入术以及心脏电生理学
and it's widely used to diagnose disease in the heart.

这些都广泛的运用于心脏疾病的诊断
That's usually not the first thing you do

这些通常都不是首选方案
because that's an invasive procedure.

因为这是一个有创性检查
What is important about EKG is that it's not invasive.

心电图的重要性就在于它是无创的
You can do it without entering the body,

你不需要进入机体内
by just measuring something that's happening on the surface.

只需要在体表进行测量
You can do it very simply by placing electrodes

只需要非常简单的在体表