Antonyms for the phrase "play heartstrings" can include words such as repel, disgust, or offend. These words indicate a negative emotional response, rather than the positive emotion that is often associated with playing heartstrings. Other antonyms may include words such as disregard, ignore, or neglect, which suggest a lack of connection or feeling.
While "play heartstrings" generally refers to an action that evokes strong emotions, particularly those of love or sympathy, its antonyms suggest the opposite - emotions that are cold, indifferent, or even hostile. However, it is important to note that antonyms often exist on a spectrum, and some words may be stronger or more extreme than others.