skip to main content

AS Cardiac Conduction — SCE Rheumatology MCQ

Instant feedback + full explanation. One question, done properly.

ModerateSpondyloarthropathyAS Cardiac ConductionSCE Rheumatology

A 55-year-old man with longstanding radiographic axial spondyloarthritis develops complete atrioventricular block requiring permanent pacemaker insertion. There is no evidence of myocardial infarction, electrolyte disturbance or treatment with an atrioventricular nodal blocking drug. Which pathological mechanism most characteristically links his rheumatic disease to the conduction abnormality?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: B — Inflammation and fibrosis extending from the aortic root into the membranous septum and atrioventricular conduction tissue

The correct answer is B. In longstanding ankylosing spondylitis, aortitis and subaortic inflammation may heal by fibrosis extending into the membranous interventricular septum, where the atrioventricular node and proximal His bundle lie. This can produce first-degree atrioventricular block, bundle-branch disease or complete heart block; related aortic-root disease may also cause aortic regurgitation. Amyloidosis is not the characteristic lesion. Coronary vasculitis is not the usual mechanism and the absence of infarction further argues against ischaemic nodal injury. Tumour necrosis factor inhibitors are not recognised as causing this characteristic fibrosing conduction lesion. Pericarditis can occur in inflammatory disease but does not ordinarily compress the His bundle or explain progressive atrioventricular block.

Reference: Palazzi C, D'Angelo S, Lubrano E, Olivieri I. Aortic involvement in ankylosing spondylitis. Clinical and Experimental Rheumatology. 2008;26 Suppl 49:S131–S134. https://pubmed.ncbi.nlm.nih.gov/18799070/