A multiparous woman in her late 20s developed postpartum angioedema, rash, profound hypotension, and decreased consciousness, progressing to acute myocardial dysfunction with left ventricular impairment. Despite thorough investigations, no clear cause was found. Anaphylaxis to medication was initially suspected as the patient had received paracetamol, ibuprofen and intrapartum antibiotics, however the symptoms resolved with cabergoline-induced lactation suppression leading to the diagnosis of lactation anaphylaxis being made. This case suggests lactation anaphylaxis can trigger transient cardiac issues, highlighting the need for awareness and further research. Lactation anaphylaxis is rarely documented, and cardiac involvement has not been previously described. Effective management of lactation anaphylaxis, particularly with cardiac complications, is crucial. This case emphasizes the importance of considering lactation anaphylaxis in postpartum allergic presentations and highlights the necessity for more research on its mechanisms and treatment.