The influence of treatment on linear and non-linear parameters of autonomic regulation in patients with acute schizophrenia

Abstract

An increased cardiovascular mortality up to three times higher than in general populations associated with an increased heart rate is reported in patients suffering from schizophrenia suggesting a cardiac autonomic dysregulation in schizophrenic patients. Mechanisms which could be responsible for this increased cardiovascular mortality are under debate (unhealthy lifestyle, smoking, diabetes, adverse pro-arrhythmic effects of antipsychotic medication, altered autonomic function). The aim of this study was to determine if medical treatment and/or schizophrenia itself causes cardiac autonomic dysregulation. We investigated 46 patients suffering from schizophrenia (acute non-mediated - G1, medicated - G2) and 23 matched (age, gender) healthy control subjects (CON). From every patient three times ECG and non-invasiv blood pressure were recorded. Cardiac autonomic regulation was evaluated by linear and non-linear (symbolic dynamics (JSD)) methods of heart rate variability (HRV), blood pressure variability (BPV) and baroreflex sensitivity (BRS). The results show that non-medicated schizophrenic patients differ significantly from CON (p<0.05) in linear and nonlinear measures. In the medicated state considerably high significant differences between schizophrenic patient and CON were found (p<0.0001). These results demonstrate that acute schizophrenia influences autonomic regulation significantly and that standard medical treatment with antipsychotics leads to an additional altered autonomic regulation in schizophrenia patients with suppressed HRV, BRS, JSD and increased BPV measures.Keywordsautonomic regulationschizophrenia