Title: Risk factors of prolonged corrected QT interval among patients with mental disorders

Abstract

Introduction

There is an increased rate of sudden cardiac death in mental health patients. Studies provide consistent evidence that prolonged QT interval is associated with higher risk of all-cause and cardiovascular mortality.

Objectives

This study aimed to assess the prevalence of prolonged QTc interval (corrected QT>450 milliseconds) and to determine the possible factors in hospitalized psychiatric patients.

Methods

We reviewed records of all mental health inpatient admissions to the psychiatry “C” department at Hedi Chaker university hospital in Sfax, between 1 february and 30 april 2019. Electrocardiogram (ECG) availability was noted and QTc interval was manually measured. Sociodemographic, clinical, biological and therapeutic data were collected.

Results

Of 68 mental health inpatient admissions, 59 (86.6 %) presentations had an ECG. A total of seven (11.8 %) had a prolonged QTc interval. These seven patients were treated with typical antipsychotics. Of the 7 patients with a prolonged QTc, 4 patients (57.1%) suffered from schizophrenia. QTc prolongation was significantly correlated with the presence of a recent physical trauma (p = 0.021), dietary restriction (p = 0.026), and taking at least two antipsychotics (p = 0.008). Moreover, this prolongation of QTc was linked to a longer duration of disease and an older age, without significant associations.

Conclusions

Our study supports an association between a prolonged QTc interval and clinical situations at risk and antipsychotic polypharmacy. However, a larger study with routine ECG screening is required to better assess the significance of this problem.