>Though unusual today, heart burial was once an accepted practice. In the Middle Ages, the hearts of saints were worshiped separately from their bodies, and the hearts of dead Crusaders were occasionally the only part sent back home,

Quite true. And this practice pre-dates the person to whom it belonged by hundreds of years. For example, when Richard I of England died, this happened

>Richard's heart was buried at Rouen in Normandy, his entrails in Châlus (where he died), and the rest of his body at the feet of his father at Fontevraud Abbey in Anjou.[133] https://en.wikipedia.org/wiki/Richard_I_of_England