Mental stress and ischemic heart disease: evolving awareness of a complex association

The connection between cardiovascular disease and psychosocial risk factors has been the subject of an ever-growing body of literature over the last 50 years. Studies on the role of negative emotions, personality traits, chronic stress and social determinants have brought to light their possible role in triggering acute coronary syndromes, although further studies are required to clarify controversial results regarding the association between cardiovascular risk and important psychological problems such as depression and anxiety. The recognition of the role of emotional events in acute coronary syndromes paved the way for provocation experiments, aimed at inducing mental stress in a controlled setting and then documenting reversible impairment of myocardial perfusion, depolarization anomalies and arrhythmias. This ultimately led to the formalization of the concept of mental stress-induced myocardial ischemia. Accumulating evidence on the mechanistic bases of such phenomena outline a wide range of central and peripheral physiological changes associated with emotions and behaviors, whose effects are exerted on the cardiovascular system, sympathetic nervous system and the hypothalamus-hypophysis neuroendocrine axis. This article outlines the main steps in the identification of psychological aspects as cardiovascular risk factors and emphasizes the relevance of emotional stress as a trigger of acute cardiovascular events. Finally, a description is provided of the pathophysiological mechanisms behind mental stress-induced myocardial ischemia and pathways connecting the heart and brain.