Prevalence of resting-ECG abnormalities in systemic lupus erythematosus: a single-center experience

Cardiovascular complications are a major cause of morbidity and even mortality among systemic lupus erythematosus (SLE) patients. Whether cardiac arrhythmias contribute to this burden among SLE patients, however, is not currently known. The goal of this study was to determine the prevalence of cardiac conduction abnormalities among SLE patients from a single center. We retrospectively reviewed the medical records of SLE patients who had 12-lead electrocardiograms (ECGs) available from various settings at a single academic center over the period of 10 years. In addition, ICD-9 codes for arrhythmias were obtained for the SLE patients whose ECGs were reviewed. The hospital setting (in-patient, out-patient, emergency department) and the indication for obtaining the ECG were evaluated. Two hundred thirty-five SLE patients had available ECGs. Sinus tachycardia was most common (18%). With direct ECG review, tachyarrhythmias were found in 6% of SLE patients, with the most common being atrial fibrillation (3%). Atrial fibrillation was seen even more frequently (9%) when ICD-9 codes were reviewed. No patients had brady-arrhythmias. QT prolongation was present in 17% of patients upon direct ECG review. More ECGs with tachyarrhythmias and QT prolongation were found among inpatients, with preoperative evaluation and gastrointestinal symptoms being the most common indications. Sinus tachycardia was the most common finding seen among our SLE patients with ECGs. Further study into the possible mechanisms behind this is warranted, including the possibility of autonomic nervous system involvement in SLE.