The title of Poe's story foreshadows the demise of the narrator who suffers from psychological terror of the consequences of time. For one thing, the sound of the title mimics the ticking of a clock as well as the beat of a heart. At any rate, this beating of the heart symbolizes the persistence of time that the narrator is unable to stop.
In addition, the title of this story also foreshadows much of the repetition that prevails throughout the narrative. Moreover, the repetitions in the story become clues to the mystery. For, besides the repetition of the old man's eye, there are two other repetitions: the concept of time and the narrator's claim that he loves the old man. Therfore, the narrator has a certain identity shared with the old man, so when he kills the old man in order to be rid of the "vulture eye," death is not the end of the narrator's terror. Instead, his own heart, aligned with the old man and their shared terror of time, becomes the "tell-tale heart," and in his psychological torture, the narrator confesses,
Almighty God!—no, no! They heard!—they suspected!—they knew!—they were making a mockery of my horror!-this I thought, and this I think. But anything was better than this agony!
Villains!” I shrieked, “dissemble no more! I admit the deed!—tear up the planks! here, here!—It is the beating of his hideous heart!”
It is, ironically, the beating of the narrator's own heart that tattles on him, not that of the old man, for, in killing the old man's eye, the narrator's "I" yet remains afterwards to answer the beating of his own "tell-tale" heart.