Increased prevalence of ECG suspicious for Brugada Syndrome in recent onset schizophrenia spectrum disorders

Abstract

Background: Schizophrenia is associated with an increased risk of sudden cardiac death, traditionally attributed to prolonged QTc interval and increased prevalence of cardiovascular risk factors. However, defective ion channels implicated in both schizophrenia and Brugada Syndrome (BrS) may be associated with an increased risk of cardiac arrhythmias. Moreover, these cardiac arrhythmias can be provoked by various drugs, including psychotropic drugs.

Objective: To assess the prevalence of the occurrence of ECG suspicious for BrS (suspect BrS-ECG) and the prevalence of BrS in patients with recent onset schizophrenia spectrum disorders (SSD).

Methods: In this case-control study, ECGs of 388 patients with recent onset SSD admitted between 2006 and 2015 and 844 healthy controls were made. All persons who had a suspect BrS-ECG were offered an ajmaline provocation test to diagnose or exclude BrS. Data on possible confounders were ascertained. Patients with and without suspect BrS-ECG were compared regarding clinical and ECG variables.

Results: Suspect BrS-ECG was found in 33 patients (8.5%) and 13 healthy controls (1.5%), with an adjusted Odds Ratio of 3.5 (p < 0.0001). This finding was not explained by potential confounders such as gender, age, ethnicity, cannabis use, cardiovascular risk factors, medication use or serum electrolytes. BrS was confirmed in three patients and one control.

Conclusion: A considerable subset of patients with recent onset SSD have suspect BrS-ECG, extending earlier findings in patients with chronic schizophrenia. Screening for BrS in schizophrenia could be relevant both to prevent sudden cardiac death and to identify a subgroup of patients with possible ion-channel dysfunctioning.

Keywords: Brugada Syndrome; Calcium channel; Cardiac arrhythmias; Endophenotype; Schizophrenia; Sudden cardiac death.