Electrocardiographic disturbances in children with systemic lupus erythematosus

BACKGROUND: Conduction disturbances other than heart block related to neonatal lupus are rarely explored and reported in children with systemic lupus erythematosus (SLE). OBJECTIVE: To report the electrocardiographic (ECG) abnormalities in children with SLE and assess whether anti-Ro/SSA antibodies and hydroxychloroquine are associated with the rhythm disturbances. METHODS: This cross-sectional retrospective study comprised patients with SLE who had regular follow-up in the Pediatric Lupus Clinic at King Faisal Specialist Hospital and Research Center-Riyadh. All enrolled patients were evaluated with regard to demographics, age at disease onset, disease duration, clinical and laboratory variables including autoantibodies, disease activity using SLEDAI disease activity index, and medications. An expert pediatric cardiologist reviewed the ECG findings of all enrolled patients independently without knowing the clinical status of the patients. RESULTS: A total of 41 (35 females, 6 males) unselected patients with SLE with a mean age of 12.8 (2.5) years and mean follow-up duration of 4 (3) years completed the evaluation. The most frequent manifestations were renal disease (65.8%), followed by musculoskeletal (46.3%), hematological (41.5%), and cardiac involvement (19.5%). Thirty-two had active disease (SLEDAI >4), and the mean of SLEDAI was 9.2 (6.2). ECG abnormalities were seen in 12 patients (29.3%); these changes included ST-T changes (9.8%), right bundle branch block (7.3%), 4 prolonged QT interval (9.8%), and low QRS voltage (2.4%). Thirty-seven (90.3%) patients were on hydroxychloroquine, and 9 patients (22%) had positive anti-Ro/SSA antibodies. ECG abnormalities were associated significantly with anti-Ro/SSA antibodies (P < .05) and a low platelet count (P < .5) but had no association with other autoantibodies, hydroxychloroquine, or SLEDAI score. CONCLUSION: Children with SLE with anti-Ro/SSA antibodies are probably prone to heart conduction abnormalities. However, the heart rate and QT interval were affected by hydroxychloroquine. A larger prospective study is required to allow more definitive conclusions.