A Gwack attack could be the opposite of a heart attack. maybe?

Like:
something so delightfully bubbly in your tummy
that it makes you feel good and want to laugh
or giggle spontaneously.

Or like when you are half awake / half asleep
and you think a thought
(that fully awake you might not find funny much,)
but for some reason,
as you were waking or starting to fall asleep,
it made you giggle inside for no perceptible reason.
(That could be a qwake attack too. )

I think a Gwack attack
would have to definitely happen
by surprise and with out forwarning
to be best experienced.

That is what comes to my mind about the word ,anyhow
*smile*
have you had a gwack attack today?
The healthy Alternative to a heart attack.
complete opposites.