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Unit VI Promoting Health in Patients With Circulatory or Perfusion Disorders
Table 30.6 Comparison of Stages of Heart Failure Development and New York Heart Association Functional Classes
American Heart Association/American College of Cardiology Stages of Heart Failure Development
New York Heart Association Classification of Functional Status
A: Has risk factors but no signs or symptoms
I: No symptoms with physical activity, such as dyspnea or chest pain
B: No signs or symptoms but elevated heart pressures or elevated BNP
II: Mild symptoms with ordinary activities
C: Current or past symptoms of HF
III: Marked limitation with physical activity but comfortable at rest IV: Severe limitation and distress with physical activity or at rest
D: Marked signs and symptoms that interfere with daily life and cause hospitalizations
HF, Heart failure; LV, left ventricle.
Interprofessional Management Medical Management Diagnosis
Medications The medical management described here is predomi- nantly for patients with HFrEF. These strategies have not been efficacious for patients with HFpEF. Management of patients with HFpEF focuses on the treatment of the underlying cause, blood pressure control, diuretics for fluid volume overload, and symptom management. The goals of HFrEF management are the reduction of risk factors, manipulation of the critical components of cardiac output (preload, afterload, and contractility), and control of the compensatory mechanisms. Successful man- agement slows disease progression, prevents complications, reduces morbidity and mortality, and improves quality of life. Risk-factor management may include blood pressure and glucose control, weight loss, optimizing serum lipids, and smoking cessation. Beta blockers are used to control the sympathetic nervous system compensatory response in HF, such as tachycardia, in order to decrease cardiac work- load. Ivabradine, a medication that slows sinus-node firing, can be added for greater control of heart rate in patients taking maximal doses of beta blockers or who do not toler- ate beta blockers. Preload is the amount of stretch in the heart at the end of diastole and is affected by the amount and pressure of blood returning to the heart. Aldosterone antagonist diuretics such as spironolactone (Aldactone) and loop diuretics such as furosemide (Lasix) are essential medica- tions to decrease preload in patients with fluid retention. The use of spironolactone should be cautioned in patients with renal insufficiency because of the potential compli- cation of hyperkalemia. In contrast, furosemide can cause hypokalemia and is often paired with a potassium replace- ment medication. Dapagliflozin (Farxiga) is a newer medi- cation first used to treat diabetes type 2, but has been found to reduce hospitalizations and death in patients with HF even without diabetes. Afterload refers to the resistance within the vasculature. Increased afterload intensifies the workload on the heart, further impairing cardiac output. Afterload reduction is a main goal of medical management. Angiotensin-converting enzyme (ACE) inhibitors are medications used to control
The diagnosis of HF is heavily dependent on history and physical assessment. The symptoms are fairly nonspe- cific, so diagnostic tests are done to rule out other dis- orders and determine the underlying cause. Diagnostic tools include chest x-ray, echocardiogram, CT, MRI, and ECG to assess the presence of structural disease, ejection fraction, heart size, pulmonary congestion, or dysrhyth- mias. Multigated acquisition (MUGA) scans can also determine EF. Nuclear imaging studies, stress testing, and coronary angiography to evaluate blood flow to the heart are performed when CAD is suspected. In severe acute HF, hemodynamic monitoring with a pulmonary artery catheter can be useful. Exercise testing and a 6-minute walk test can be useful in evaluating functional abilities. Diagnostic Tests Laboratory testing includes cardiac biomarkers, serum electrolytes, a complete blood count, urinalysis, glucose level, fasting lipid profile, liver function testing, and renal function tests. Biomarkers, BNP and N-terminal pro- B-type natriuretic peptide (NT-proBNP), are increased because of the overstretching of the ventricles. These tests can be used to diagnose HF, guide clinical decision mak- ing, track a patient’s response to therapy as well as indicate disease progression, and evaluate risk of death and hospi- talization. Cardiac biomarkers such as troponins are used to rule out an acute ischemic event, but can also be an indi- cator of HF if they are chronically elevated. Electrolytes can be outside the normal range as a result of decreased kidney perfusion or medication. For example, potassium might be low because of diuretic therapy. Also, inadequate flow to the kidneys may impair renal function, resulting in elevated creatinine and blood urea nitrogen (BUN) levels. Decreased hemoglobin and hematocrit levels may indicate anemia, which may be a result of decreased blood flow to the kidneys that reduces the production and function of erythropoietin in the kidneys.
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