Functional Classification of Heart Disease

In the management of patients with heart disease, it is important to quantify and closely follow the severity of symptoms. A commonly used classification system is that of the New York Heart Association, shown below. However, in following individual patients, it is better to document specific activities that produce symptoms, such as walking distance, stairs climbed, or activities of daily living.

Class I: No limitation of physical activity. Ordinary physical activity does not cause undue fatigue, dyspnea, or anginal pain.
Class II: Slight limitation of physical activity. Ordinary physical activity results in symptoms.
Class III: Marked limitation of physical activity. Comfortable at rest, but less than ordinary activity causes symptoms.
Class IV: Unable to engage in any physical activity without discomfort. Symptoms may be present even at rest.