The word(s) "heart" appears 213 time(s) in 195 verse(s) in Quran in Abdullah Yusuf Ali translation.

(141) Allah has revealed (from time to time) the most beautiful Message in the form of a Book, consistent with itself, (yet) repeating (its teaching in various aspects): the skins of those who fear their Lord tremble thereat; then their skins and their hearts do soften to the celebration of Allah's praises. Such is the guidance of Allah: He guides therewith whom He pleases, but such as Allah leaves to stray, can have none to guide.

(142) When Allah, the One and Only, is mentioned, the hearts of those who believe not in the Hereafter are filled with disgust and horror; but when (gods) other than He are mentioned, behold, they are filled with joy!

(143) Warn them of the Day that is (ever) drawing near, when the hearts will (come) right up to the throats to choke (them); No intimate friend nor intercessor will the wrong-doers have, who could be listened to.

(144) (Allah) knows of (the tricks) that deceive with the eyes, and all that the hearts (of men) conceal.

(145) "(Such) as dispute about the Signs of Allah, without any authority that hath reached them, grievous and odious (is such conduct) in the sight of Allah and of the Believers. Thus doth Allah, seal up every heart - of arrogant and obstinate Transgressors."

(146) And there are (other) advantages in them for you (besides); that ye may through them attain to any need (there may be) in your hearts; and on them and on ships ye are carried.

(147) They say: "Our hearts are under veils, (concealed) from that to which thou dost invite us, and in our ears in a deafness, and between us and thee is a screen: so do thou (what thou wilt); for us, we shall do (what we will!)"

(148) As to the Thamud, We gave them Guidance, but they preferred blindness (of heart) to Guidance: so the stunning Punishment of humiliation seized them, because of what they had earned.

(149) What! Do they say, "He has forged a falsehood against Allah"? But if Allah willed, He could seal up thy heart. And Allah blots out Vanity, and proves the Truth by His Words. For He knows well the secrets of all hearts.

(150) Then seest thou such a one as takes as his god his own vain desire? Allah has, knowing (him as such), left him astray, and sealed his hearing and his heart (and understanding), and put a cover on his sight. Who, then, will guide him after Allah (has withdrawn Guidance)? Will ye not then receive admonition?