What are the causes of rheumatic heart disease?

Rheumatic fever is an acute or chronic systemic inflammatory disease of connective tissue, mainly involving the joints, heart, skin and subcutaneous tissues, following recurrent infection of the pharynx with group A beta haemolytic streptococci. Rheumatic heart disease, on the other hand, is a complication of severe or recurrent episodes of rheumatic fever, mainly manifesting as heart valve lesions.