Table 1.

Classification of heart failure

New York Heart Association Classification of Heart Failure [14]
Class 1	No limitation of physical activity. Ordinary physical activity does not cause undue fatigue, palpitations, dyspnea, or angina pain
Class 2	Slight limitation of physical activity. Patients are comfortable at rest. Ordinary physical activity results in fatigue, palpitation, dyspnea, or angina pain
Class 3	Marked limitation of physical activity. Patients are comfortable at rest. Less than ordinary activity causes fatigue, palpitation, dyspnea, or angina pain
Class 4	Inability to carry on any physical activity without discomfort. Symptoms of heart failure or the angina syndrome may be present even at rest. Any physical activity increases discomfort.
American College of Cardiology/American Heart Association Classification of Heart Failure [13]
Stage A	High risk for HF but without structural heart disease or symptoms of HF
Stage B	Structural heart disease but without signs of symptoms of HF
Stage C	Structural heart disease with prior or current symptoms of HF
Stage D	Refractory HF requiring specialized interventions