Comfortable at rest, but ordinary physical activity results in symptoms of HF. III Marked limitation of physical activity. Comfortable at rest, but less than ordinary activity causes symptoms of HF. IV Unable to carry on any physical activity without symptoms of HF, or symptoms of HF at rest. D Refractory HF requiring specialized interventions IV Unable to carry on any physical activity without symptoms of HF, or symptoms of HF at rest. ACCF indicates American College of Cardiology Foundation; AHA, American Heart Association; HF, heart failure; and NYHA, New York Heart Association. Yancy et al. JACC Vol. 62, No. 16, 2013 2013 ACCF/AHA Heart Failure Guidelines: Executive Summary October 15, 2013:1495 539 3. Volume status and vital signs should be assessed at each patientencounter.Thisincludesserialassessmentofweight,as wellasestimatesofjugularvenouspressureandthepresenceof peripheral edema or orthopnea (48 51). (Level of Evidence: B) 5.1.2. Risk Scoring CLASS IIa 1. Validated multivariable risk scores can be useful to estimate subsequent risk of mortality in ambulatory or hospitalized patients with HF (52 60). (Level of Evidence: B) 5.2. Diagnostic Tests CLASS I 1. Initial laboratory evaluation of patients presenting with HF should include complete blood count, urinalysis, serum electro- lytes (including calcium and magnesium), blood urea nitrogen, serum creatinine, glucose, fasting lipid pro le, liver function tests, and thyroid-stimulating hormone. (Level of Evidence: C) 2. Serial monitoring, when indicated, should include serum electrolytes and renal function. (Level of Evidence: C) 3. A 12-lead electrocardiogram should be performed initially on all patients presenting with HF. (Level of Evidence: C) CLASS IIa patients who present with HF (63). (Level of Evidence: C) 2. Diagnostic tests for rheumatologic diseases, amyloidosis, or pheochromocytoma are reasonable in patients presenting with HF in whom there is a clinical suspicion of these diseases. 