CARDIOVASCULAR SYSTEM ( CVS ) Explain/Define Rheumatic fever Rheumatic fever is an autoimmune collagen disease usually caused by a hypersensitivity reaction to group A, B-hemolytic streptococcal (GABHs) infection. In rheumatic fever, inflammatory lesions of connective tissues and endothelial tissues occur. It usually affects the heart, joints, blood vessels, and other connective tissues. Mainly the cardiac valve (mainly the mitral valve) is affected. These diseases are mainly seen in children aged