Objective: Large-artery stiffness and arterial wave reflections have been identified as independent markers and prognosticators of cardiovascular risk. Mental stress is a novel risk factor for coronary artery disease and has been associated with left ventricular dysfunction, myocardial ischemia and infarction, and sudden cardiac death. The purpose of this study was to assess the effect of acute mental stress on aortic stiffness and wave reflections.
Methods: The effect of a mental arithmetic test was assessed in 19 healthy individuals using a randomized, sham-procedure-controlled, crossover design. Carotid-femoral pulse wave velocity and augmentation index were measured as indices of aortic stiffness and wave reflections, respectively.
Results: Mental stress induced a sustained increase in central systolic and pulse pressure throughout the whole study (systolic: by 7.5 mm Hg, p < .05; pulse: by 5.7 mm Hg, p < .01). The increase in peripheral systolic and pulse pressure was not significant throughout the study, but only when their peak values were compared with baseline (systolic: by 6.2 mm Hg, peak at 0 minutes; pulse: by 6.6 mm Hg, peak at 5 minutes, p < .05 for both). There was a sustained increase in pulse wave velocity (by 0.57 m/s, p < .005) throughout the study denoting a sustained increase in aortic stiffness. Similarly, augmentation index showed a sustained increase with mental stress (by 6.16%, p < .05) denoting increased wave reflections from the periphery.
Conclusion: Acute mental stress results in a prolonged increase in aortic stiffness and wave reflections. Given the important pathophysiologic and prognostic role of these parameters, our results provide important mechanistic links between acute mental stress and increased cardiovascular risk.