The Blazing or Flaming Heart can be found in the 11th degree of the Ancient and Accepted Scottish Rite (“Sublime Elect of the Twelve”).
It can also be seen on this Adoption apron.

Also in some systems of the Ancient and Accepted Scottish Rite, the flaming heart is part of the emblem of the 26th degree “Prince of Mercy”.

(top) Morals and Dogma, Albert Pike, (1871)
(middle) Apron from the Adoption system of John Yarker (1833-1913)
(bottom) general jewel