Assessment of inhomogeneities of repolarization in patients with systemic lupus erythematosus.

OBJECTIVES: Systemic lupus erythematosus (SLE) is a chronic disease that affects many organ systems and manifests a broad spectrum of laboratory and clinical features. SLE patients have an increased risk of developing cardiovascular disease. The aim of this study was to evaluate inhomogeneities of repolarization by using Tpeak -Tend (Tp-e) interval and Tp-e/QT ratio were measured from the 12-lead surface electrocardiogram (ECG) in patients with SLE.

MATERIAL AND METHOD: This study included 69 SLE patients (69 females; mean age 35.8 ± 10.2) and 57 control subjects (57 females; mean age 34.5 ± 8.9). Transthoracic echocardiographic examination was done in all participants. QT parameters, Tp-e intervals and Tp-e/QT ratio were measured from the 12-lead ECG. These parameters were compared between groups.

RESULTS: No statistically significant difference was found between two groups in terms of basic characteristics. Diastolic function parameters were similar between the two groups (P > 0.05). In electrocardiographic parameters analysis, QT dispersion (QTd) and corrected QT dispersion (cQTd) were significantly increased in SLE patients compared the control group (49.5 ± 16.4 ms vs. 32.8±11.7 ms and 56.7 ± 19.5 ms vs. 36.4 ± 13.1 ms, all P value < 0.001). Tp-e interval and Tp-e/QT ratio were also significantly higher in SLE patients (82.8 ± 18.9 vs. 72.4 ± 17.6 and 0.22 ± 0.05 vs. 0.19 ± 0.05, P = 0.002 and P = 0.001, respectively). Tp-e interval and Tp-e/QT were positively correlated with disease duration (r = 0.29, P = 0.01 and r = 0.24, P = 0.04, respectively).

CONCLUSION: Our study revealed that QTd, cQTd, Tp-e interval and Tp-e/QT ratio increased in patients with SLE. Also, Tp-e interval and Tp-e/QT were positively correlated with disease duration.