ABSTRACT
Heart valves are essential to the normal function of the heart and cardiovascular/cardiopulmonary systems. When functioning properly, the heart valves allow unrestricted, unidirectional blood flow through the heart for subsequent distribution throughout the body. Consequently, valve disease or dysfunction can result in significant harm, as the reduction in the forward flow of blood limits the oxygenation of the tissues and can induce cardiac, cardiovascular, or cardiopulmonary compensation. Valve disease is prevalent in our society, with valve replacement or repair in approximately 90,000 people in the United States in 2001 [1] (275,000 worldwide [2]). Moreover, valve disease can be either congenital or acquired. For example, approximately 9 to 14 of every 10,000 children born are affected with the Tetralogy of Fallot [3,4], a congenital heart disorder characterized by a narrowing of the pulmonary valve among other anomalies. Acquired valve disease can affect people of all ages and may be due to an infectious agent (rheumatic heart disease, endocarditis), systemic diseases (lupus, carcinoid syndrome), other cardiac disease, trauma, pharmacologic agents, aging-related changes, or many other causes, some of which remain unknown [5].
