Defibrillation in sodium blocked channels

[jdgi]

Hi, I need help in understanding why defibrillation is unlikely to be successful in VT associated with Tricyclic antidepressant overdose. It has to so with the block in the fast sodium channels, I know, but what happens if you do defibrillate anyway.

[Psycho]

It sends an electric shock through the body that is supposed to work as an artificial action potential to stop the heart from fluttering, however if the voltage gated channel proteins aren't working no action potentials can be sent period, unless you introduce an inhibitor of the drug previous to the attempt.

[jdgi]

Thanks, that is clear and succinct!