There seems to be a definite lag between the cardiac reaction and the first visible signs of life. That would be the time necessary for the first heartbeats to circulate the bloodstream throughout the entire body.
11 seconds sound clip from the The Curse of Frankenstein movie soundboard.
You can hear this line at 00:13:06.253 in the Blu-ray version of the movie.
Quote context
[...]
- It took us years of unrelenting work to discover what we were seeking.
- Then, one night out of sight and sound of the rest of the house, our efforts were rewarded.
(Electricity crackling in Frankenstein's lab)
(Water bubbling in Frankenstein's lab)
- Paul, it's alive. Paul, we've done it!
- Think what that would mean when it came to performing major surgery!
- We could save hundreds of lives.
- Reducing shock to a minimum, no loss of blood.
- Victor, the Medical Federation meets next month in Berne. Can we have our paper ready by then?
[...]