Throughout the story the narrator's hears a heartbeat over and over again. My literary device is used in the form of a heartbeat because it happens multiple times.
Throughout the story the Narrator is haunted by the old man's eye. "He had the eye of a vulture- a pale blue eye, with a film over it. Whenever it fell Upon me my blood ran cold." This shows that there is a conflict in the story because the narrator gets mad whenever he sees the old man's eye.
The character contradicts himself in the scene when he yells out in agony because he hears the Old man's heart beating after he is dead. The Man claimed that he wasn't mad but he heard a dead man's heart beating which makes him contradict himself.