De subitaneis mortibus. XXIII. Rheumatoid arthritis and ankylosing spondylitis

Area of Science:

• Cardiovascular Pathology
• Rheumatic Diseases
• Cardiac Electrophysiology

Background:

• Investigating the cardiac conduction system in patients with rheumatic diseases is crucial for understanding sudden cardiac death.
• Rheumatoid arthritis and ankylosing spondylitis are systemic inflammatory conditions that can affect multiple organs, including the heart.

Observation:

• Necropsy examination of three patients (two with rheumatoid arthritis, one with ankylosing spondylitis) revealed significant cardiac conduction system abnormalities.
• All patients exhibited cardiac electrical instability, with two experiencing sudden death.
• Histological findings included sinus node degeneration, and degenerative disease in the atrioventricular (A-V) node and His bundle.

Findings:

• Electrophysiological abnormalities ranged from atrial fibrillation to complete heart block.
• Marked narrowing, and in some cases virtual occlusion, of the nutrient arteries supplying the A-V node and His bundle was observed.
• Sinus node degeneration was present in all cases, though sinus node arteries were not significantly abnormal.

Implications:

• These findings suggest a strong link between rheumatic disease, cardiac conduction system pathology, and potentially fatal arrhythmias.
• Understanding these pathological mechanisms may inform strategies for managing cardiac complications in patients with rheumatoid arthritis and ankylosing spondylitis.
• Comparison with cardiac findings in other connective tissue diseases like lupus, polyarteritis nodosa, and scleroderma highlights shared and distinct pathological pathways.