Highly refractile myocardial echoes in familial amyloidosis with polyneuropathy. A correlative echocardiographic and histopathological study.

Two-dimensional echocardiography in systemic amyloidosis has in most cases shown highly refractile myocardial echoes. The morphological basis for this finding has so far been little examined. In the present study, echocardiographic examinations were performed in vitro on autopsied hearts from ten patients with familial amyloidosis with polyneuropathy (FAP). An ultrasonically visible needle was used to localize the abnormal echoes, and samples were taken for histological analysis of the region of the echocardiographic abnormality. Our results indicate that the highly refractile myocardial echoes in FAP are due to nodules composed of collagen and amyloid.