Many general diseases affect the heart and can be classified according to the part of the heart affected or the nature of the changes produced. Inflammatory infections are divided into pericarditis, myocarditis, and endocarditis. Valvular diseases are one of the most important groups in which any of the four valves may be stenosed; associated with this group are hypertrophy in which the heart is enlarged, and dilation, in which one or more of the cavities is dilated. Degeneration of the muscular tissue may take place in the direction either of a fatty or, less commonly, of a fibroid change. There is also a class of functional disorders in which palpitation, irregularity, rapidity, slowness or even severe attacks of pain appear. If the defect of the heart be so great that it must be remedied by compensation, the pumping power of the heart weakens and symptoms appear either to the heart itself (pain and palpitation) or to other organs—for example: breathlessness, faintness, dyspepsia, swelling of the abdomen, dropsy of the feet.
The American Heart Association estimated the cost of heart disease in 1996 to be $66.4 billion, which covers hospital and home nursing care costs, drugs, physicians' bills and lost work time by patients. An American economics institute judged the cost of heart and blood vessel diseases to be $164 billion in 1992, excluding workers' compensation administration, insurance health benefits and social security costs.
According to the Australian Bureau of Statistics (2014), of the leading causes of death cardiovascular disease is at number one, heart failure is at number seven; hypertensive diseases are at 13, and cardiac arrhythmias at 19.