Is "breast" in "My Lord, expand for me my breast" meant to be the mind, and what is the difference between it and the heart, given the existence of supplications such as "O Turner of hearts"?

The chest is the well-known location of the heart. It is broader and more comprehensive than the heart, serving as its arena that receives incoming perceptions and collects them before they enter the heart. Satan whispers in the chests, and his whisper reaches the hearts, because the chest is the meeting point, the reservoir of psychological forces, and the collection place of the morsels, and the heart is part of it. Some scholars have elaborated that the mention of the heart in the Qur'an refers to intellect and knowledge, while the mention of the chest refers to all faculties such as intellect, desire, inclination, and anger. Furthermore, scrutiny pertains specifically to the heart because it is more specific than affliction.