Someone having a heart attack may experience any or all of the following symptoms:
A heart attack generally causes chest pain for more than 15 minutes, but it can also have no symptoms at all. Many people who experience a heart attack have warning signs hours, days or weeks in advance.
" ... warning signs hours, days or weeks in advance ... "
If you notice that someone is choking it is important to contact your local paramedical services as soon as possible to ensure that the person gets medical treatment to ensure that there were no internal damage obtained.
The danger from an electrical shock depends on the type of current, how high the voltage is, how the current travelled through the body, the person’s overall health and how quickly the person is treated.