Influence of mental stress on ventricular pump function in postinfarction patients. An invasive hemodynamic investigation. To assess the influence of mental stress on ventricular pump function in coronary patients, 88 postinfarction patients (mean age, 53 +/- 10 years) performed mental arithmetic during Swan-Ganz catheterization monitoring a mean of 44 +/- 16 days after myocardial infarction. The test lasted 3 minutes in 66 patients and 10 minutes in 22 patients. Two patients suffered acute pulmonary edema a few minutes after mental arithmetic, but no others complained of symptoms. Mean heart rate increased from 76 +/- 14 to 92 +/- 17 beats/min, mean systolic blood pressure increased from 138 +/- 22 to 160 +/- 27 mm Hg, mean diastolic blood pressure increased from 89 +/- 10 to 101 +/- 15 mm Hg, mean pulmonary wedge pressure increased from 13 +/- 6 to 19 +/- 8 mm Hg (p less than 0.001), and mean stroke volume decreased from 72 +/- 18 to 65 +/- 18 ml (p less than 0.001) during mental arithmetic. The changes in central hemodynamics during mental arithmetic were not predictable from noninvasive parameters. In the 22 patients who performed 10-minute mental arithmetic, the changes persisted throughout mental exercise. Eighty-one patients underwent supine bicycle ergometry after mental arithmetic: Absolute mental arithmetic-pulmonary wedge pressure values correlated with those during exercise at the first stage (25 W) (r = 0.63, p less than 0.001) and at maximal load (77 +/- 29 W) (r = 0.49, p less than 0.001), and pulmonary wedge pressure change between stress values and baseline during mental arithmetic did not correlate with those during the first stage of exercise (r = 0.09, p = NS) or during maximal load (r = 0.11, p = NS). Twenty-nine patients repeated the study 1 year after myocardial infarction, and the same hemodynamic changes were observed during mental arithmetic. In conclusion, it appears that mental stress can cause deteriorations of central hemodynamics that can be independent of changes in heart rate and blood pressure and are not predictable from exercise-induced changes; stress-induced cardiovascular activation can last for at least 10 minutes and is stable over long time periods. 