Impact of Chronic Emotional Stress on Myocardial Function in Postmenopausal Women and Its Relationship with Endothelial Dysfunction

Background and Objectives: An association between chronic stress and cardiovascular diseases has been described, but the underlying mechanisms have not been fully elucidated. We investigate the impact of perceived stress on the left ventricular (LV) and endothelial functions in postmenopausal women. Subjects and Methods: We investigated 64 consecutive postmenopausal women (mean age $56.7{\pm}9.7$ years) with atypical chest pain and chronic stress. Patients with coronary heart disease were excluded. Global and segmental longitudinal deformation parameters of LV were used as parameters to assess myocardial function and brachial flow-mediated dilatation (FMD) was used to assess the endothelial function, and patients were analyzed by the Symptom Checklist 90 Revised (SCL-90-R) to determine emotional stress. The study participants were divided into two groups, based on global severity index (GSI): ${\geq}50$ (group A, n=27) or <50 (group B, n=37). Results: Although there were no significant differences in LV geometry or myocardial performance indices between the groups, global LV strain was significantly reduced in group A compared to group B ($-16.6{\pm}2.7%$ vs. $-19.1{\pm}1.9%$, p=0.001). There were also significant differences in the value of reactive FMD ($6.6{\pm}2.2%$ vs. $9.5{\pm}2.9%$, p<0.001), and same result was observed for nitroglycerine-induced dilatation ($14.6{\pm}4.7%$ vs. $18.0{\pm}5.8%$, p=0.016). Multivariate linear regression analysis showed that GSI was the only significant attributor to global LV strain ($\beta$=0.149, p=0.008) and reactive FMD ($\beta$=-0.200, p=0.041). Conclusion: Chronic emotional stress may exert negative effects on the LV and endothelial functions, which may be associated with the severity of stress. This study provides a possible mechanism by which stress is associated with an increased risk of cardiovascular dysfunction.