Antonyms for the phrase "changed of heart" include words that reflect a steadfastness of belief or opinion. Some of these words may include "unwavering," "resolute," "determined," or "steadfast." These words imply that once a person has made a decision or formed an opinion, they are unlikely to change it. Additionally, words such as "stubborn," "inflexible," or "rigid" may also be considered antonyms of "changed of heart," as they indicate a lack of willingness to budge or reconsider one's position. Overall, the antonyms for "changed of heart" point towards a sense of unwavering conviction or stubbornness in one's beliefs.