Evaluation of Tp-e interval and Tp-e/QT ratio in dermatomyositis and analysis of their relationship with inflammation

Objective. Dermatomyositis(DM) is a chronic multi-systemic inflammatory rheumatic disorder. Malignant arrhythmia are the leading cause of morbidity and mortality in patients withDM. The Tp-e interval and Tp-e/QT ratio have been accepted as new markers for the assessment of myocardial repolarization and ventricular arrhythmogenesis. The aim of this study was to evaluate ventricular repolarization by using Tp-e interval and Tp-e/QT ratio in patients with DM, and to assess the relation with inflammation. Methods. This study included 281 DM patients (180 females, 101 males; mean age 52.73 ± 15.80 years) and 281 control subjects (180 females, 101 males; mean age 53.38 ± 15.72 years). QTc, Tp–e interval and Tp–e/QT ratio were measured from the 12-lead ECG. The plasma level of blood routine test, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) were measured. These parameters were compared between groups. Results. No statistically significant difference was found between two groups in terms of basic characteristics. In electrocardiographic parameters analysis, QTc, Tp–e interval and Tp–e/QT ratio were significantly increased in DM patients compared the control group (441.44 ± 26.62 ms vs 422.72 ± 11.7 ms and 104.16 ± 24.34 ms vs 77.23 ± 16.25 ms and 0.27 ± 0.06 ms vs 0.20 ± 0.04 ms, all P value < 0.001). Tp–e interval and Tp–e/QT were positively correlated with NLR, CRP, and ESR (all P value < 0.001). Conclusion. Our study demonstrated that QTc, Tp-e interval, and Tp-e/QT ratio were increased in DM patients. Also, the Tp–e interval and Tp–e/QT ratio were positively correlated with the level of NLR, CRP, and ESR.