Infection and inflammations of heart structures are very common. This can cause certain structural and functional changes in the heart, which can lead to decreased cardiac output and thereby cause poor tissue perfusion. This chapter describes the endocarditis, myocarditis, pericarditis, rheumatic fever and rheumatic heart disease along with their incidence, etiology and risk factors, classification, pathophysiology, clinical manifestations, diagnostic evaluation, complications, management, nursing diagnosis and intervention, home care, and prevention. Inflammatory involvement of the endocardium layers of the heart is called endocarditis. Endocarditis includes infection of heart valve and endothelial structure of the heart. It is microbial infection of heart valve. The term myocarditis implies inflammation of heart muscles. Though most heart disease affect myocardial layer of heart myocarditis is a disease, which is very specific to myocardium. Pericardium is a sac that covers support and protects heart.