Modern songs, films, novels and daily speech often use heart imagery to illustrate ‘inner self’ experiences, such as deeply felt emotions. Where do these ideas come from and what relevance do they have for medicine today? This article explores some of the key origins and periods of development of heart/‘inner self’ ideas before considering the significance of heart/‘inner self’ interactions in modern clinical practice: from Aristotelian anatomy and the translated Hebrew Scriptures; through Shakespeare, William Harvey and the Protestant Reformation; to (...) theories of emotion and modern-day cardiology. I conclude that heart/‘inner self’ interactions exist in clinically significant ways, but are poorly understood and under-recognised in healthcare settings. Greater integration of cardiovascular and psychosocial medicine would improve patient care. (shrink)