A heartbeat is one of the oldest tricks in sound design, long used in film and television to signal danger, longing or panic without dialogue. As short-form video editing grew, the same effect moved onto soundboards and editing apps, where creators could drop a ready-made pulse under horror clips, romantic edits and dramatic countdowns. Its simple rhythm works because everyone recognises it instantly, and it needs no context to create tension. That familiarity is why it remains a staple for editors making suspenseful or emotional content today.