Coronary heart disease and cardiac conduction abnormalities in persons with psychotic disorders in a general population

We investigated the prevalence of coronary heart disease (CHD) and myocardial infarction (MI) in persons with DSM-IV psychotic disorders. We also examined cardiac conduction abnormalities, and the role of antipsychotic medication in them. The study was based on a nationally representative survey of 8028 persons aged 30 years or over from Finland. Diagnoses of CHD and MI were based on electrocardiographic findings, health examination, and register information. QTc was calculated using the Bazett formula, and Minnesota classification was used for conduction abnormalities. We found that large Q-waves suggesting past MI were significantly more frequent in persons with schizophrenia, while the prevalence of CHD in persons with psychotic disorders did not differ significantly from the remaining study sample. Prevalence of prolonged QTc interval was significantly increased in persons with schizophrenia and in users of typical antipsychotics. However, low-potency antipsychotic use but not diagnosis of schizophrenia remained an independent predictor of prolonged QTc interval in a logistic regression. Low-potency antipsychotic use was associated with ventricular conduction defects, and high-potency antipsychotic use with premature beats. Symptoms and signs of CHD should be actively monitored patients with schizophrenia, and the electrocardiogram should be monitored for all types of changes in persons receiving antipsychotic medication.