Assessment of the Relationship Between Dose and Number of Effective Used Drugs on on QT Interval in Patients with Lupus

Systemic lupus erythematosus is an autoimmune and multi-organ disease. Cardiovascular involvement is one of the most important causes of death in these patients. In some studies, it has been observed that the prolongation of the QTc interval is a prognostic factor in cardiovascular failure.

In this study, we intended to assess the role of drugs used in treating patients with lupus on the prolonged QTc interval.

This descriptive-analytical study was carried out on 150 patients with SLE referring to Rheumatology Clinics in the City of Arak during the years 2014 and 2015. Then, ECGs were taken from all patients in two phases, first on admission and second six hours later. The QTc interval was determined using Bazett’s formula. The results were analyzed using SPSS version 16 software.

The mean age of the studied patients was 35.36 ± 11.8 years and 80.7% were females. An anti-Ro/SSA antibody and treatment with hydroxychloroquine were significantly associated with the prolongation of QTc in patients; however, the duration and dosage of hydroxychloroquine did not affect the QTc interval.

Based on the obtained results, hydroxychloroquine may influence the cardiac condition of patients; thus, it needs more studies in this field.