In patients with familial amyloidosis with polyneuropathy, cardiac conduction disturbances are primarily caused by direct amyloid infiltration of the atrioventricular conduction system.
Cardiac conduction disturbances are frequent in amyloidosis with cardiac involvement, but the pathogenesis of these electrocardiographic abnormalities is not clear. In the present study, the conduction systems in six patients with the Swedish variety of familial amyloidosis with polyneuropathy (FAP), have been analyzed. The results suggest that in FAP, direct amyloid infiltration of the atrioventricular conduction system accounts for the majority of the electrocardiographic disturbances.
Eriksson et al. (Fri,) studied this question.