Any disorder of the heart.
Examples include coronary heart disease , congenital heart disease , and pulmonary heart disease , as well as rheumatic heart disease (see rheumatic fever ), hypertension , inflammation of the heart muscle (myocarditis) or of its inner or outer membrane ( endocarditis , pericarditis), and heart valve disease. Abnormalities of the heart's natural pacemaker or of the nerves that conduct its impulses cause arrhythmia s. Some connective tissue diseases (notably systemic lupus erythematosus , rheumatoid arthritis , and scleroderma ) can affect the heart. Heart failure may result from many of these disorders.