Poe's writings in general have a subversive feature in which the standards of American nineteenth-century life are replaced by a different "order" expressed in the minds and actions of his hero-villains. In Poe's tales either an authority figure or figures representing convention and conformity are struck down by a kind of mad, uncontrolled force exercised by these "rebels" (though the term almost seems too mild for what we see in the stories).
In "The Cask of Amontillado," Montresor presents himself as avenging some insult or series of slights he's received, yet whatever it is Fortunato has done to him, murder is obviously not the usual or deserved punishment. Like the rich old man in "The Tell-Tale Heart, " Fortunato represents the establishment. Both Montresor and the narrator in the latter story are paranoid and psychotic, but their intention is to destroy figures whose implicit authority they wish to challenge, albeit in a deranged way.
Montresor seems to regard himself as fulfilling a mission not only for himself but for others. The total dedication, the single-mindedness he puts into his task of killing without the slightest self-questioning is that of a sociopath, but a sociopath is one who is mentally ill and does not recognize or respond to the rules of society. Burying Fortunato in the ancient catacomb may even be symbolic of the burying of the authority that Montresor wishes to subvert.
Even the narrator of "The Black Cat," though motivated by sadism in his alcoholic rages, is one who rebels against the conventionality of his domestic arrangement. We are at first shown a stable home life of an apparently model citizen, his wife and pets. All of this is systematically brought down, culminating in the murder of Pluto and of the man's wife. What was previously a sublimated, sick form of anger against domesticity is brought into the open and climaxes as he describes himself burying the axe in his wife's brain.
The one story in which the rebellion against authority of the protagonist is the most complete is probably "Hop-Frog," where the victims are a king and his courtiers. In this case, though carried out with the usual grisly cruelty and sadism, it's also justified in a way those of the other stories are not. Hop-Frog is a little person, a court jester insulted and jeered at in the court where he serves, as is his friend, the young girl Tripetta. The horrific death for Hop-Frog's victims is quicker but perhaps crueler than that of Fortunato, but the symbolism of revolt and vengeance by a seeming nobody against the rich and powerful is at least as striking.
One might still question that the "American Victorianism" of your question is actually the object of these characters's anger and hatred. One has to remember, however, that nineteenth-century authors's techniques involved finding modern meanings in the past or in remote places and situations. Just as the Puritan New England of 200 years before served as the basis of Hawthorne's critique of timeless injustice and hypocrisy, Poe also uses the framework of a blurred, dreamlike setting as a stand-in for the societal values that have not really changed, even in a still-new country that prided itself on its supposed discarding of the conflicts and thinking of the Old World.
Poe himself, despite the remarkable output of his writings and his activity as an editor, was a misfit, a man alienated from the "respectable" life. His isolation and alienation are expressed in his characters, who destroy the societal fabric that surrounds them and oftentimes themselves as well.