[Changes in the heart conduction system in a case of Wegener's granulomatosis]

Since the initial description by Klinger in 1931 and confirmation by Wegener in 1936, Wegener's granulomatosis has emerged as an uncommon disease entity of unknown aetiology. This disease is characterized by a granulomatous-necrotizing general vasculitis, which most frequently affects the respiratory tract, and by a usually focal necrotizing glomerulonephritis. We report one case of Wegener's granulomatosis with reference to heart conduction system involvement and to nervous plexuses localized in the heart. Specialized conduction system of the heart is little investigated in Wegener's granulomatosis. The blocks of tissue containing the sinoatrial node, the atrio-ventricular node, His bundle, the bifurcation and both bundle branches were fixed in buffered formalin 10% and embedded in paraffin, cut serially at 150 mu intervals and stained alternately with hematoxylin-eosin and Heidenhain trichromic (azan). This heart showed fibrosis near distal His bundle, coronaric arteriolar severe stenosis and fibrotic involvement of the root of the left branch. This histological picture is plausibly and result of scarring of arteriolar specific granulomatous process, also in relation to the low grade of coronarosclerosis. Sclerosis of specific conduction tissue, in addition to cardiac intramural arteriolar subocclusion and to aspecific inflammation of nervous plexuses, can be considered as a plausible arrhythmogenic base of death.