Conduction system in systemic lupus erythematosus with atrioventricular block

Area of Science:

• Pediatric Cardiology
• Rheumatology
• Pathology

Background:

• Systemic lupus erythematosus (SLE) is a chronic autoimmune disease.
• Cardiac involvement in SLE can be severe, affecting conduction system.
• Complete heart block is a rare but serious complication in pediatric SLE.

Purpose of the Study:

• To describe the clinical course and postmortem cardiac findings.
• To investigate the cause of complete heart block in a pediatric SLE patient.
• To differentiate the role of hyperkalemia versus lupus in cardiac conduction abnormalities.

Main Methods:

• Case report of a 12-year-old girl with SLE, renal failure, and hyperkalemia.
• Detailed clinical course documentation.
• Serial section examination of the cardiac conduction system (sinoatrial and atrioventricular nodes).

Main Results:

• The patient presented with complete heart block, renal failure, and hyperkalemia.
• Postmortem examination showed sinoatrial and atrioventricular nodes replaced by granulation tissue.
• This replacement was attributed to systemic lupus erythematosus, not hyperkalemia.

Conclusions:

• Granulation tissue in the cardiac conduction system is a significant finding in pediatric SLE.
• Systemic lupus erythematosus, not hyperkalemia, was the cause of complete heart block in this case.
• This case highlights the critical need for early diagnosis and management of cardiac complications in pediatric SLE.