The Physiological Indicators of Early Cardiac Dysfunction in Patients with Schizophrenia

Background: Schizophrenia is a serious mental illness which usually first manifest in younger adulthood. When the illness extends into the age between 50 and 60 years, patients with schizophrenia are at an elevated risk of excessive deaths due to cardiovascular diseases. In general population, impaired left ventricular longitudinal strain detected by two-dimensional speckle tracking echocardiography is the useful predictor of future cardiovascular events. Therefore, early identification of the indicators for impaired left ventricular longitudinal strain would be of value on the prevention against the subsequent cardiovascular morbidity and mortality. However, current data still remain limited regarding the physiological indicators of impaired left ventricular longitudinal strain in patients with schizophrenia.Hypothesis: Patients with schizophrenia are at a high risk of impaired left ventricular longitudinal strain and related atherosclerosis during younger adulthood because of metabolic, inflammatory, and autonomic nervous dysregulation linked to pathophysiology of schizophrenia itself, unhealthy behaviors associated with psychopathology, and adverse effects of psychotropic medications.Aims: To determine the physiological indicators of impaired left ventricular longitudinal strain in patients with schizophrenia during younger adulthood.Methods: In the ongoing 3-year study, we prepare to recruit physically healthy patients who age between 20 and 50 years and have DSM-IV schizophrenia from Taipei Medical University Hospital, Wanfang Hospital, Shuang Ho Hospital, and Taipei City Psychiatric Center. Each case subject will be matched with one control without psychiatric or cardiovascular diseases based on the age (±2 years) and sex. Two-dimensional speckle tracking echocardiography will be conducted by board-certified cardiologists to obtain the data of left ventricular longitudinal strain. Information related to the severity of psychopathology, use of psychotropic medications, and changes of metabolic, inflammatory, and autonomic nervous function linked to schizophrenia pathophysiology will be collected by psychiatric interview, chart review, and laboratory tests. After collecting the data, we will use generalized estimating equation in the statistical model to identify the physiological indicators of impaired left ventricular longitudinal strain in patients with schizophrenia during younger adulthood.Significances: It is estimated that a total of 200 schizophrenic cases and 200 age-and-sex matched normal controls will be recruited in this study. Hopefully, our results will be helpful in identifying the physiological indicators of impaired left ventricular longitudinal strain in patients with schizophrenia during younger adulthood.