Rheumatic fever and rheumatic heart disease are systemic inflammatory diseases primarily affecting the connective tissue and usually preceded by group A streptococcal infection. They can lead to acute rheumatic endocarditis characterized by small vegetations along the mitral valve margin. Advanced cases result in chronic rheumatic heart valve disease like mitral stenosis and aortic regurgitation. Long-term management involves eradicating streptococcal infection, suppressing inflammation, and secondary prevention with antibiotics.