Atrial Natriuretic Peptide

Common use

Specimen

Normal findings

Description

This procedure is contraindicated for

N/A

Indications

• Assist in the confirmation of congestive heart failure (CHF), as indicated by increased level
• Identify asymptomatic cardiac volume overload, as indicated by increased level

Potential diagnosis

Increased in

• ANP is secreted in response to increased hemodynamic load caused by physiological stimuli as with atrial stretch or endocrine stimuli from the aldosterone/renin system.

• Asymptomatic cardiac volume overload
• CHF
• Elevated cardiac filling pressure
• Paroxysmal atrial tachycardia

Decreased in

N/A

Critical findings

N/A

Interfering factors

• Drugs that may increase ANF levels include atenolol, candoxatril, captopril, carteolol, morphine, oral contraceptives, vasopressin, and verapamil.
• Drugs that may decrease ANF levels include clonidine, erythropoietin, prazosin, ramipril, and urapidil.
• Recent radioactive scans or radiation within 1 wk before the test can interfere with test results when radioimmunoassay is the test method.
• Failure to follow dietary and medication restrictions before the procedure may cause the procedure to be canceled or repeated.

Nursing Implications and Procedure

Pretest

• Positively identify the patient using at least two unique identifiers before providing care, treatment, or services.
• Patient Teaching:  Inform the patient this test can assist in assessing heart function.
• Obtain a history of the patient’s complaints, including a list of known allergens, especially allergies or sensitivities to latex. Be alert to signs and symptoms of altered cardiopulmonary tissue perfusion related to ventilation-perfusion imbalance, decreased cardiac output related to altered muscle contractility, and fluid-volume excess related to glomerular filtration rate.
• Obtain a history of the patient’s cardiovascular system, symptoms, and results of previously performed laboratory tests and diagnostic and surgical procedures.
• Obtain a list of the patient’s current medications, including herbs, nutritional supplements, and neutraceuticals (see Effects of Natural Products on Laboratory Values).
• Note any recent procedures that may interfere with test results.
• Review the procedure with the patient. Inform the patient that specimen collection takes approximately 5 to 10 min. Address concerns about pain and explain that there may be some discomfort during the venipuncture.
• Sensitivity to social and cultural issues, as well as concern for modesty, is important in providing psychological support before, during, and after the procedure.
• Instruct the patient to fast for 6 to 12 hr before the test and to avoid taking medications that interfere with test results, as directed by the health-care provider (HCP). Note: Drugs such as β-blocking agents, calcium antagonists, cardiac glycosides, and vasodilators can affect results.
• Prepare an ice slurry in a cup or plastic bag to have ready for immediate transport of the specimen to the laboratory. Prechill the specimen collection tube in the ice slurry.

Intratest

• Potential complications: N/A
• Ensure that the patient has complied with dietary, medication, or activity restrictions and pretesting preparations; assure that food has been restricted for at least 6 to 12 hr prior to the procedure.
• Avoid the use of equipment containing latex if the patient has a history of allergic reaction to latex.
• Instruct the patient to cooperate fully and to follow directions. Direct the patient to breathe normally and to avoid unnecessary movement.
• Observe standard precautions, and follow the general guidelines in Patient Preparation and Specimen Collection. Positively identify the patient, and label the appropriate specimen container with the corresponding patient demographics, initials of the person collecting the specimen, date, and time of collection. Perform a venipuncture.
• Remove the needle and apply direct pressure with dry gauze to stop bleeding. Observe/assess venipuncture site for bleeding or hematoma formation and secure gauze with adhesive bandage.
• The sample should be placed in an ice slurry immediately after collection. Information on the specimen label should be protected from water in the ice slurry by first placing the specimen in a protective plastic bag. Promptly transport the specimen to the laboratory for processing and analysis.

Post-Test

• Inform the patient that a report of the results will be made available to the requesting HCP, who will discuss the results with the patient.
• Instruct the patient to resume usual diet and medication, as directed by the HCP.
• Nutritional Considerations: Increased ANF may be associated with coronary artery disease (CAD). Nutritional therapy is recommended for patients identified to be at risk for developing CAD or for individuals who have specific risk factors and/or existing medical conditions (e.g., elevated LDL cholesterol levels, other lipid disorders, insulin-dependent diabetes, insulin resistance, or metabolic syndrome). Other changeable risk factors warranting patient education include strategies to encourage patients, especially those who are overweight and with high blood pressure, to safely decrease sodium intake, achieve a normal weight, ensure regular participation in moderate aerobic physical activity three to four times per week, eliminate tobacco use, and adhere to a heart-healthy diet. If triglycerides also are elevated, the patient should be advised to eliminate or reduce alcohol. The 2013 Guideline on Lifestyle Management to Reduce Cardiovascular Risk published by the ACC and AHA in conjunction with the NHLBI recommends a “Mediterranean”-style diet rather than a low-fat diet. The new guideline emphasizes inclusion of vegetables, whole grains, fruits, low-fat dairy, nuts, legumes, and nontropical vegetable oils (e.g., olive, canola, peanut, sunflower, flaxseed) along with fish and lean poultry. A similar dietary pattern known as the DASH diet makes additional recommendations for the reduction of dietary sodium. Both dietary styles emphasize a reduction in consumption of red meats, which are high in saturated fats and cholesterol, and other foods containing sugar, saturated fats, trans fats, and sodium.
• Recognize anxiety related to test results, and be supportive of fear of shortened life expectancy. Discuss the implications of abnormal test results on the patient’s lifestyle. Provide teaching and information regarding the clinical implications of the test results, as appropriate. Educate the patient regarding access to counseling services. Provide contact information, if desired, for the American Heart Association (www.americanheart.org) or the National Heart, Lung, and Blood Institute (www.nhlbi.nih.gov).
• Reinforce information given by the patient’s HCP regarding further testing, treatment, or referral to another HCP. Answer any questions or address any concerns voiced by the patient or family.
• Depending on the results of this procedure, additional testing may be performed to evaluate or monitor progression of the disease process and determine the need for a change in therapy. Evaluate test results in relation to the patient’s symptoms and other tests performed.

Related Monographs

• Related tests include aldosterone, antiarrhythmic drugs, ADH, apolipoprotein A and B, AST, BNP, blood gases, CRP, calcium/ionized calcium, cholesterol (total, HDL, and LDL), CK and isoenzymes, CT scoring, echocardiography, glucose, glycated hemoglobin, Holter monitor, homocysteine, ketones, LDH and isoenzymes, lipoprotein electrophoresis, magnesium, MRI chest, myocardial infarct scan, myocardial perfusion heart scan, myoglobin, PET heart, potassium, renin, sodium, triglycerides, and troponin.
• See the Cardiovascular System table at the back of the book for related tests by body system.