Hemodynamic and emotional responses to a psychological stressor after cardiac transplantation

Objective: Because cardiac transplantation entails neuronal decentralizatio n, cardiac responses to a psychological stressor in transplant patients wou ld be expected to rely on circulating hormonal factors and therefore to be delayed and prolonged. We tested this prediction by comparing stress respon ses after transplantation with those in patients with coronary artery bypas s grafts (to control for experience of surgery) or heart failure (to contro l for heart disease). Methods: Fifty-six transplantation patients, 66 bypas s patients, and 40 patients with heart failure underwent a 10-minute, compu ter-generated, Stroop color-word conflict test. Heart rate and systolic and diastolic blood pressures were recorded continuously for 1 minute before, during, and 12 minutes after the stressor. Emotional state was measured per iodically by questionnaires, Results: All hemodynamic variables were increa sed by the Stroop test. There was a pattern of blunted response to the Stro op test after cardiac transplantation, particularly in comparison with bypa ss patients, and slower recovery in comparison with both control groups. Em otional stress responses were similar in each group. Conclusions: This patt ern cannot be attributed to the experience of major heart surgery of to car diac disease. Nor can it be explained by differences in central processing of stress. Correspondingly the changed hemodynamic response to the Stroop t est after cardiac transplantation evidently does not affect patients' emoti onal responses, The hemodynamic findings are consistent with an increased r eliance on hormonal rather than neuronal hemodynamic regulation after cardi ac transplantation.