Effect of mental stress on left ventricular ejection fraction and its relationship to the severity of coronary artery disease

To evaluate the relationship between the mental stress-induced decrease in left ventricular ejection fraction (LVEF) and the severity of exercise-indu ced ischaemia 20 patients with stable coronary artery disease (CAD) underwe nt radionuclide ventriculography during mental stress testing and stress my ocardial perfusion single-photon emission tomography (SPET). We also examin ed whether changes in haemodynamic and neurohormonal parameters are related to changes in LVEF during mental stress. The LVEF decreased from 54.8% +/- 17.7% to 49.89 +/- 16.2% with mental stress (P < 0.0005). Ten of the 20 pa tients (50.0%) had a <greater than or equal to>5% decrease in LVEF The rema ining ten patients had no or a <5% decrease in LVEF There was a significant correlation between the change in LVEF during mental stress and the size o f the reversible defect on stress myocardial perfusion SPET (r = -0.80, P < 0.0005), with close regional correspondence (75% identical). This correlat ion was less strong in the 12 patients with a total defect score at rest of <10 (r = -0.69, P = 0.013) than in the eight patients with a total defect score at rest of <greater than or equal to>10 (r = -0.94, P = 0.001). The c hanges in blood pressure and heart rate were not significantly correlated w ith the change in LVEF but the percent change in adrenaline concentration c orrelated with the change in LVEF It is suggested that mental stress impair s systolic function by inducing transient myocardial ischaemia. The effect of neurohormonal responses during mental stress on LV systolic function may also be important in patients with CAD.