Answer:
The field of psychology that studies how people's behavior interacts with stress and heart disease is called Psychocardiology. Psychocardiology is an interdisciplinary field that combines the study of psychology, behavioral medicine, and cardiology to understand the relationship between psychological factors, behavioral factors, and cardiovascular health. Psychocardiology research focuses on how stress, personality, coping strategies, and other psychological factors can impact the development and progression of heart disease, as well as how behavioral interventions can improve cardiovascular health outcomes.