New York Heart Association (NYHA) Functional Classification for Heart Failure
NYHA Classification
NYHA Functional Class
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Stratifies severity of heart failure by symptoms.
When to Use
Patients with signs and symptoms of heart failure.
Formula
NYHA Heart Failure Classification Criteria Class I No limitation of physical activity; ordinary physical activity does not cause undue fatigue, palpitation, or dyspnea Class II Slight limitation of physical activity; comfortable at rest; ordinary physical activity results in fatigue, palpitation, or dyspnea Class III Marked limitation of physical activity; comfortable at rest; less than ordinary activity causes fatigue, palpitation, or dyspnea Class IV Unable to carry on any physical activity without discomfort; symptoms of heart failure at rest; if any physical activity is undertaken, discomfort increases
Pearls / Pitfalls
Often criticized for being outdated, subjective, and with limited reproducibility (56% according to one study by Goldman et al). Nevertheless, it is still commonly used in both research and clinical settings. Functional class is not necessarily linked to treatment strategy; the more modern ACC/AHA Heart Failure Staging is one attempt to bridge the gap.
Advice
Use objective measures of heart failure severity such as echocardiography and 6 Minute Walk Distance to further stratify functional capacity and make treatment decisions.