Judging from the first line and the second hint, this is likely to be
a medical term, probably one not found in a lot of dictionaries.
So let's try to piece it together from the wordplay.
My start invokes electric dissuasion,
This makes me think of electro-shock therapy or electro-convulsive therapy. Perhaps the start of the word is EST or ECT? (We know it's a six-letter word thanks to the first hint.)
My middle is a place in Canada,
I'd guess, given the length of the word, that this is going to be an abbreviation for some well-known Canadian city. Perhaps TOR for Toronto?
But my end, in territories is imperative.
Still haven't figured this out. I suspect there might be wordplay involved, e.g. "imperative" meaning the imperative form of a verb rather than just necessary.
Overall, it looks like we have
a 6-letter medical term beginning with EST or ECT, possibly ESTOR or ECTOR. I've checked some online resources, and the only matching medical terms I could find were ECTOMY and ECTOPY and ESTHES, none of which really fits the bill.