Mental Stress-Induced Myocardial Ischemia

Abstract

Acute psychological stress induced in the laboratory can provoke myocardial ischemia in a substantial proportion of cardiac patients. This phenomenon, known as mental stress-induced myocardial ischemia (MSIMI), represents a “proof-of-concept” of the adverse effects of acute psychological stress on the heart in susceptible individuals. MSIMI clearly demonstrates that ischemic responses can be induced by relatively mild behavioral challenges similar to those that might be encountered in everyday life and not merely by extreme emotional stress. MSIMI has considerable prognostic significance, since it is linked to about twofold increased risk of cardiac events and mortality. Despite this, MSIMI remains relatively understudied and underappreciated. Some subgroups of patients, such as women and individuals with depression, appear to be especially vulnerable to MSIMI for reasons that are not yet clear; whether MSIMI plays a role in the adverse outcomes associated with depression needs further study. MSIMI is clearly distinct from ischemia induced by conventional stress testing, such as exercise or pharmacological stress testing. It is typically without pain, generally not related to severity of coronary artery disease, and occurs at lower levels of oxygen demand. Stress-induced vascular changes, particularly increases in systemic vascular resistance, coronary artery vasomotion, and microvascular function, may all contribute to this pattern of ischemia. While evidence of effective interventions for MSIMI is still limited, emerging data suggest that selective serotonin reuptake inhibitors and perhaps angiotensin-converting enzyme inhibitors might be beneficial in patients with MSIMI, as well as behavioral interventions for stress reduction.