Pathologic Evidence of Granulomatosis With Polyangiitis as a Cause of Atrioventricular Block.

BACKGROUND

Atrioventricular block (AVB) is a rare manifestation of granulomatosis with polyangiitis (GPA), and the underlying pathologic relationship between GPA and AVB remains poorly understood.

CASE SUMMARY: We present the case of a 71-year-old woman who developed complete AVB and had a history of microscopic polyangiitis. Despite the absence of clinical signs indicative of GPA relapse throughout her lifetime, postmortem examination revealed microgranulomas and multinucleated giant cells within the atrioventricular node.

DISCUSSION: This case provides pathologic evidence that GPA can lead to complete heart block as an initial clinical manifestation.

TAKE-HOME MESSAGES: GPA-associated AVB can improve with immunosuppressive therapy. GPA should be considered in the differential diagnosis of AVB of unknown etiology.