How does Edgar Allan Poe create suspense using narrative structure?

Traditionally, "narrative structure" refers to the framework that a story is built with. Most teachers will teach a 5 piece narrative structure. It's often accompanied with a diagram in the shape of a triangle/pyramid. The 5 parts of the narrative structure are exposition, rising action, climax, falling action, and conclusion.
The question asks how Poe creates suspense in the narrative structure. Without knowing which specific story by Poe that the question refers to, it's hard to dial in a specific answer; however, Poe consistently uses some of the same techniques in many of his stories. For my answer, I will focus on the exposition part of the narrative structure. The exposition of a story is going to introduce readers to characters and setting. Poe will often immediately begin building suspense from this first moment. Take setting for example. Poe likes to set his stories during the night. Things are scarier at night time. In "The Raven," we are told that the narrator is pondering at midnight.

Once upon a midnight dreary, while I pondered, weak and weary,

The same night time setting occurs in "The Cask of Amontillado" as well.

It was about dusk, one evening during the supreme madness of the carnival season, that I encountered my friend.

The room in "The Pit and the Pendulum" is so dark that the narrator can't even see the pit.
Another way that Poe builds suspense right from the exposition is to introduce readers to scary, weird, and/or unreliable narrators. Montresor tells readers in the first sentence that he has vowed revenge. The narrator of "The Pit and Pendulum" tells readers that he is "sick unto death with that long agony," and the narrator of "The Tell-Tale Heart" is trying to convince his readers that he's sane (all while admitting he hears voices from Hell).

I heard many things in hell. How, then, am I mad? Hearken! and observe how healthily—how calmly I can tell you the whole story.
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