Bread and Butter Lesion

Diffuse fibrinous and serofibrinous ‘stringy’ adhesions or plaque-like thickening on the chronically inflamed pericardium of rheumatic heart disease; similar lesions occur in connective tissue disease—e.g., lupus, viral pericarditis—post-acute MI, neoplasia, uremia, trauma, radiation, and Fusobacterium infection; the end-result may be restrictive pericardial fibrosis, which compromises the inflow of blood to the ventricle