QT dispersion in patients with systemic lupus erythematosus: the impact of disease activity

Abstract

BackgroundPatients with systemic lupus erythematosus (SLE) have increased cardiovascular morbidity and mortality. Although autopsy studies have documented that the heart is affected in most SLE patients, clinical manifestations occur in less than 10%. QT dispersion is a new parameter that can be used to assess homogeneity of cardiac repolarization and autonomic function. We compared the increase in QT dispersion in SLE patients with high disease activity and mild or moderate disease activity.Methods and ResultsOne hundred twenty-four patients with SLE were enrolled in the study. Complete history and physical exam, ECG, echocardiography, exercise test and SLE disease activity index (SLEDAI) were recorded. Twenty patients were excluded on the basis of our exclusion criteria. The patients were divided to two groups based on SLEDAI: 54 in the high-score group (SLEDAI > 10) and 50 in the low-score group (SLEDAI < 10).QT dispersion was significantly higher in high-score group (58.31 ± 18.66 vs. 47.90 ± 17.41 respectively; P < 0.004). QT dispersion was not significantly higher in patients who had received hydroxychloroquine (54.17 ± 19.36 vs. 50.82 ± 15.96, P = 0.45) or corticosteroids (53.58 ± 19.16 vs. 50.40 + 11.59, P = 0.47). There was a statistically significant correlation between abnormal echocardiographic findings (abnormalities of pericardial effusion, pericarditis, pulmonary hypertension and Libman-Sacks endocarditis) and SLEADI (P < 0.004).ConclusionsQT dispersion can be a useful, simple noninvasive method for the early detection of cardiac involvement in SLE patients with active disease. Concerning high chance of cardiac involvement, cardiovascular evaluation for every SLE patient with a SLEDAI higher than 10 may be recommended.Trial registrationClinicaltrial.gov registration NCT01031797

Assessment of Inhomogeneities of Repolarization in Patients with Systemic Lupus Erythematosus

“…28 Heart rhythm disorders can be related with CAD, myocarditis, or small vessel vasculitis with collagen deposition and fibrosis affecting the conduction system in SLE. 16,17 In our study, we found significant differences in QTd and cQTd between SLE patients and control group. 16,17 In our study, we found significant differences in QTd and cQTd between SLE patients and control group.…”

“…The QT duration, in particular heart rate-corrected QT interval duration and QT dispersion remain the most common measure for repolarization abnormalities both in clinical and research settings. 17 Prolonged QTd and cQTd that we found in our study may reflect silent myocardial involvement in SLE patients. 16 Kojuri et al reported that QTd was significantly increased in SLE patients with high disease activity compared to patients with low disease activity.…”

“…It follows that the duration of the M cell action potential determines the QT interval, whereas the duration of the epicardial action potential determines the QT peak interval, and the Tp-e interval may provide an index of transmural dispersion of repolarization. 11,17,33 So, Tp-e may be useful index for predicting ventricular tachyarrhythmias. 13,29 In most of these studies the difference in action potential duration between epi-/endocardial cells and M cells was suggested to cause lethal arrhythmia.…”

“…8 The T peak -T end (Tp-e) interval has been accepted as a measure of global dispersion of repolarization and is one of the risk factors for life-threatening ventricular arrhythmias in adults. 9, 14 Ventricular repolarization was previously evaluated by using QT interval measurements in patients with SLE, [15][16][17] but Tp-e interval and Tp-e/QT ratio have not been studied in SLE patients before. It may be also a predicting factor for elevated risk of sudden cardiac death in patients with heart disorders.…”

ECG non-specific ST-T and QTc abnormalities in patients with systemic lupus erythematosus compared with rheumatoid arthritis

“…It is known that QTc length and QT dispersion correlate with disease activity and cytokine levels in both patients with SLE and patients with RA 711 30 48–51 We used the SLEDAI-2K, DAS28-CRP and CRP levels (as well as IL-6 levels in the RA group) to estimate disease activity. CRP levels were lower in the RA cohort as compared with the SLE cohort, and the IL-6 levels in the RA group were approximately three times lower than what has been reported in patients with active disease 52.…”