Copyright © 1980 by the European Society of Cardiology.
© 1980 The European Society of Cardiology
The morphology of the atrioventricular node in scleroderma — a three-dimensional reconstruction
Departments of Pediatrics and Medicine, UCLA Center for the Health Sciences, Los Angeles, California 90024, U.S.A.
Received 14 July 1980; .
Requests for reprints to: Nigel K. Roberts, M.D., Departments of Medicine, Division of Cardiology, UCLA Center for the Health Sciences, Los Angeles, CA 90024, U.S.A.
A new technique for looking at the atrioventricular node and bundle is described and applied to the conducting system in six patients with scleroderma. The conducting system blocks were removed, sectioned, appropriately stained and photographed. Outlines of the atrioventricular node and bundle were generated and digitized. From the digital information three-dimensional images were generated and the atrioventricular node and bundle were rotated so that the shape could be studied from any view. In striking contrast to normal atrioventricular nodal reconstructions, those from the patients who had scleroderma showed a narrow and flattened proximal atrioventricular node. The nodal microscopy, on the other hand, did not differ significantly in architecture. It is postulated that the alterations by fibrous replacement of the proximal node could account for the relatively high frequency of atrioventricular conduction Scleroderma, problems in patients with scleroderma and could paradoxically account for the relatively frequent occurrence of supraventricular tachycardias that are also found in this disease.
Key Words: Scleroderma • atrioventricular node • atrioventricular bundle • first degree heart block