Disclaimer: I have no medical expertise.

It would probably help to have seen this Kill Bill vol 2, if you don't
know what Pai Mei's Five Point Palm Exploding Heart Technique is, but
let me describe it:

In Kill Bill vol 2, Pai Mei's Five Point Palm Exploding Heart
Technique is a Kung-Fu move where the attacker pokes their opponent in
five spots on their chest around the heart, and then wallops them once
on the chest in the area surrounded by the spots they just poked.
Then they let the doomed opponent walk away.  On the fifth step they
die - their heart having exploded.

Of course, this is just some over-the-top nonsence that Quentin
Tarantino made up.

However, it is cool.  

What do y'all think of the plausability of some kind of technique like
this existing?

I've heard some vague rumors about people dropping dead from having
their Vagus Nerve touched.  Might there be anything to this?