The nurse practitioner is educating a 59-year-old man newly diagnosed with heart failure about his diagnosis. Because this patient is comfortable at rest or with mild activity, under which class of heart failure would this patient be categorized according to the New York Heart Association Functional Classification of Heart Failure?

Choice A reason: Class I heart failure is defined as patients who experience no limitation of physical activity. Ordinary physical activity does not cause undue fatigue, palpitation, or dyspnea, which fits the description of this patient. Choice B reason: Class II involves slight limitation of physical activity; the patient is comfortable at rest but ordinary activity results in symptoms. This patient is asymptomatic with ordinary activity, so Class II is less appropriate. Choice C reason: Class III involves marked limitation of physical activity; patients are comfortable at rest but less than ordinary activity causes symptoms. The patient is not experiencing this degree of limitation. Choice D reason: Class IV involves inability to carry on any physical activity without discomfort; symptoms may be present at rest. The patient does not have this level of functional limitation.