Mccallum patch in rheumatic heart disease is seen in?

Ans. (b) Left atriumRef: Robbins 8th edition, Chapter 11Mural endocardial lesions can be seen as MacCallum plaques in rheumatic heart disease. These plaques appear as map-like areas of thickened, roughened, and wrinkled part of the endocardium in the left atrium. Perhaps they are caused by regurgitant jets of blood flow, due to incompetence of the mitral valve