Macrophage activation syndrome is an uncommon yet dangerous and potentially fatal complication of many rheumatic diseases, inducing multiple organ failure, including, although rarely, acute heart failure. In the following paper, we present a case of a 37-year-old woman who, in a short period of time after a gynecological procedure due to fetal death, developed full-blown lupus erythematosus leading to early stages of macrophage activation syndrome with acute heart failure as its main clinical manifestation. We also include herein a brief literature review of the current understanding of diverse macrophage populations and their functions in various organs (focusing especially on the heart muscle), as well as a summary of different attempts at composing concise criteria for diagnosing macrophage activation syndrome.