<P> The New York Heart Association (NYHA) Functional Classification provides a simple way of classifying the extent of heart failure . It places patients in one of four categories based on how much they are limited during physical activity; the limitations / symptoms are in regard to normal breathing and varying degrees in shortness of breath and / or angina . </P> <P> It originated in 1902, when no measurements of cardiac function were possible, to provide a common language for physicians to communicate . Despite difficulties in applying it, such as the challenge of consistently classifying patients in class II or III, because functional capacity is such a powerful determinant of outcome it remains arguably the most important prognostic marker in routine clinical use in heart failure today . </P>

New york heart association classification of heart disease in pregnancy