A cardiac event is softer than a seizure and lasts a short while.
It is more like fainting for the dog, and it recovers faster.
Do not be alarmed when your dog gets a seizure; it may be a while before they get another attack, and if the attacks become frequent, your vet will come in handy.
You may have witnessed a dog having a seizure, and it is not a pleasant sight.
A seizure in a dog is characterised by a sudden fall, followed by violent jerking spasm of the four legs, frothing at the mouth and sometimes losing control of bladder and the bowel, followed by complete loss of consciousness.