Severe Acquired Long QT Syndrome in Childhood-Onset Systemic Lupus Erythematosus

BACKGROUND: Childhood-onset systemic lupus erythematosus (cSLE) is a chronic inflammatory disease that can affect any organ system, including the heart. Cardiac rhythm abnormalities are a known complication. CASE SUMMARY: A pediatric patient presented with new-onset SLE complicated by seizures and myopericarditis. During induction immunosuppression, electrocardiogram showed severe QTc prolongation. Extensive investigation failed to identify a primary cause. Ultimately, escalation of immunosuppression led to sustained resolution of QTc prolongation. DISCUSSION: While there is a known association between acute myopericarditis and QTc prolongation, this case highlights a severe prolongation of the QTc that rapidly improved only after appropriate immunomodulation and in the absence of other cardiac dysfunction. TAKE-HOME MESSAGES: This case notes the importance of expedient monitoring and treatment of severely prolonged QTc with concurrent investigation into the etiology. The case also illustrates the role of immunosuppression in the treatment of acquired long QT syndrome in cSLE.