Effects of Medication and Pathophysiology on 12-lead Electrocardiograms in Bipolar Disorder and Schizophrenia

BackgroundCardiovascular disease is the principal cause of death among patients with bipolar disorder and schizophrenia. We hypothesized that a combination of psychophysiology and the use of lithium, along with antipsychotics, alter electrocardiophysiological activity in bipolar and schizophrenic patients.PurposeThe goal of this study was to evaluate the effects of psychotropic agents and the pathophysiology using 12-lead electrocardiograms (EKGs) in bipolar and schizophrenic patients.MethodsThe study involved three groups of patients: (1) 30 lithium/haloperidol-treated patients with bipolar mania (15 males, 15 females); (2) 33 lithium-free patients with bipolar mania (21 males, 12 females); and (3) 31 lithium-free schizophrenic patients (15 males, 16 females). Clinical data were obtained through a retrospective review of the medical records of all subjects.ResultsThe mean PQ interval, QRS complex, and corrected QT (QTc) intervals did not differ among the three groups. Among those in the lithium/haloperidol-treated bipolar mania group, the QTc interval demonstrated a marginally significant correlation with serum lithium levels (r = 0.373; p = 0.05).ConclusionPathophysiological changes or minor abnormalities of electrocardiophysiological activity in schizophrenia and bipolar disorder patients might not be displayed by routine 12-lead EKGs. Because of the limitations of 12-lead EKGs, bipolar manic patients who have higher serum lithium levels might have increased risks for QTc prolongation, and thus QTc intervals should be carefully followed-up in these patients.