QT interval prolongation in schizophrenia: A cross-sectional study from a tertiary care center in Raipur

Background & objectives Antipsychotic drugs can cause QT interval prolongation (QTIP), which can lead to life-threatening cardiac manifestations. The objective of this study was to find out the prevalence of QTIP in stable patients of schizophrenia attending the outpatient department/clinic. Methods A total of 88 consenting individuals with schizophrenia aged ≥18 yr of either sex (male or female), who were stable on treatment and adherent to the prescribed medications, were included. Patients with any other psychiatric disorder, mental retardation, substance dependence other than caffeine/nicotine, or if they had taken any other drug with moderate to high risk of causing QTIP, were excluded. A 12-lead ECG was recorded. Corrected QT interval was calculated using Fridericia’s and Bazett’s formulae. Results QTIP was seen in 3 (3.4%) study participants according to Fridericia’s formula and in 6 (6.8%) study participants according to Bazett’s formula. The recorded demographic, anthropometric, and clinical/treatment variables did not differ among participants with and without QTIP. Interpretation & conclusions Prevalence of antipsychotic drug-induced QTIP in patients with schizophrenia seems to be low, but it poses a risk to life. Regular screening for additional risk factors and periodic assessment of cardiac rhythm via ECG could help prevent potentially fatal cardiac manifestations.