NYHA classes

Functional Capacity	Objective Assessment
Class I	Cardiac disease but no limitation of physical activity
Class II	Cardiac disease resulting in slight limitation; ordinary physical activity causes symptoms
Class III	Cardiac disease resulting in marked limitation; less than ordinary activity causes symptoms
Class IV	Cardiac disease resulting in inability to carry out any physical activity without symptoms; symptoms present at rest

Symptoms include fatigue, palpitations, dyspnea, or anginal pain.