1. Chapter 29Drugs Treating Heart FailureCopyright 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins

2. Copyright 2012 Wolters Kluwer Health | Lippincott Williams & WilkinsQuestion What is the normal amount of blood that is ejected fromthe heart with each contraction? A. 45 mL B. 50 mL C. 75 mL D. 100 mL 3. Copyright 2012 Wolters Kluwer Health | Lippincott Williams & WilkinsAnswer C. 75 mL Rationale: The amount of blood that is ejected fromthe heart with each contraction is 75 mL. This isreferred to as the stroke volume. 4. Physiology The volume of blood that leaves the left ventricle in 1minute is the cardiac output. Cardiac output consists of two elements, stroke volumeand heart rate. Stroke volume is the amount of blood that leaves the leftventricle with each contraction. Stroke volume is dependent on three factors: preload,contractility, and afterload.Copyright 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins 5. Physiology (cont.) Contractility also is affected by the concentration ofcatecholamines in the heart muscle. Peripheral resistance (PR) = pressure diameter ofvessel. Contractions of the heart are dependent on the uniqueelectrical conduction system of the cardiac muscle.Copyright 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins 6. Systemic CirculationCopyright 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins 7. Pathophysiology Heart failure (HF) is associated with high morbidity andhigh mortality. Pathologic processes that may cause HF occur either inthe heart itself or systemically. Cardiac output decreases when the left ventricle isunable to eject its normal volume of blood during systole. The heart muscle enlarges (cardiomyopathy) to providemore contractile force to try to improve cardiac output.Copyright 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins 8. Pathophysiology (cont.) In HF, left-sided failure occurs first, then right-sidedfailure. Natriuretic peptides are endogenous cardiac hormones.Brain natriuretic peptide, working with atrial natriureticpeptide, regulates cardiovascular homeostasis and fluidvolume. It is secreted primarily by the ventricular tissue inresponse to changes in wall tension.Copyright 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins 9. Classification of Heart FailureCopyright 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins 10. Drugs to Treat Chronic Heart Failure When the heart cannot achieve the normal cardiac outputfor various reasons, a backlog of blood, or congestion,occurs, and heart failure develops. Several drug classes are used to treat CHF, andpolypharmacy is considered the standard and mosteffective treatment. Research suggests that the clinical benefits of ACEinhibitors and beta blockers are related to modifying thechanges that occur in the left ventricle with CHF.Copyright 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins 11. Drugs to Treat Chronic Heart Failure(cont.) Additionally, the following agents should be given toselected patients: cardiac glycosides (digoxin),aldosterone antagonists, ARBs, and the combinationvasodilatorantianginal (hydralazineisosorbide) for blackpatients. Drug therapy has been effective in increasing survival ofindividuals with CHF.Copyright 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins 12. Cardiac Glycosides The cardiac glycosides also are known as digitalispreparations or digitalis glycosides. Digoxin is used to maintain clinical stability and improvesymptoms, quality of life, and exercise tolerance inpatients with all phases of CHF. Digoxin does not decrease mortality from CHF. Current AHA/ACC guidelines recommend that digoxin canbe added to reduce hospitalizations for HF or for ratecontrol if patients also have atrial fibrillation.Copyright 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins 13. Cardiac Glycosides (cont.) Digoxin is not used as the primary treatment forstabilizing patients with acute episodes ofnoncompensated heart failure. Digoxin increases the force of cardiac contraction,increasing cardiac output. Prototype drug: digoxin (Lanoxin)Copyright 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins 14. Digoxin: Core Drug Knowledge Pharmacotherapeutics Used in the treatment of CHF and atrial fibrillation Pharmacokinetics Administered: oral and IV. Absorption: varies withformulation of administration. Excreted: kidneys Pharmacodynamics It exerts an indirect effect on the heart fromstimulation of the autonomic nervous system and adirect action on both the cardiac muscle and thespecialized electrical conduction system of the heart.Copyright 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins 15. Digoxin: Core Drug Knowledge (cont.) Contraindications and precautions Heart block, ventricular fibrillation andhypersensitivity Adverse effects Dysrhythmias, anorexia, nausea, vomiting, diarrhea,headache, weakness, apathy, drowsiness, visualdisturbances, confusion, restlessness, disorientation,seizures, delirium, hallucinations, neuralgia, andpsychosis Drug interactions Multiple drugsCopyright 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins 16. Digoxin: Core Patient Variables Health status Assess cardiac rhythm, weight, and renal function. Life span and gender Determine pregnancy status and age. Lifestyle, diet, and habits Determine the patients normal dietary intake ofpotassium, calcium, and magnesium. Environment Assess environment where drug will be given.Copyright 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins 17. Digoxin: Nursing Diagnoses and Outcomes Decreased Cardiac Output related to altered cardiacfunction Desired outcome: The patients CHF will be wellcontrolled. Risk for Injury related to drowsiness, confusion,disorientation, seizures, delirium, hallucinations, andpsychosis secondary to adverse effects of drug therapy Desired outcome: The patient will not sustain aninjury related to adverse drug events while on drugtherapy.Copyright 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins 18. Digoxin: Planning and Interventions Maximizing therapeutic effects Rapid onset of therapeutic effects; the patient isdigitalized with an IV or PO loading dose. Assess for therapeutic and adverse effects beforeeach dose. Minimizing adverse effects Digoxin has a narrow therapeutic index. It is important to monitor the serum levels ofCopyright 2012 Wolters Kluwer Health | Lippincott Williams & Wilkinsdigoxin. 19. Digoxin: Teaching, Assessment, andEvaluations Patient and family education Explain the reason for taking digoxin and the adverseeffects of the drug. Teach patient how to monitor pulse. Discuss that OTC drugs can interact with digoxin. Ongoing assessment and evaluation Monitor the patients pulse rate throughout therapy. Symptoms of CHF should improve.Copyright 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins 20. Copyright 2012 Wolters Kluwer Health | Lippincott Williams & WilkinsQuestion Digoxin has a wide therapeutic range. A. True B. False 21. Copyright 2012 Wolters Kluwer Health | Lippincott Williams & WilkinsAnswer B. False Rationale: Digoxin has a very narrow therapeutic range. 22. Natriuretic Peptides The natriuretic peptide is a new class of drugs used totreat CHF. Prototype drug: nesiritide (Natrecor)Copyright 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins 23. Nesiritide: Core Drug Knowledge Pharmacotherapeutics Use in adults with acute, decompensated HF. Pharmacokinetics Administered: IV. Excreted: kidneys. Onset: rapid Pharmacodynamics Stimulates natriuretic peptide A/B receptors,promoting smooth muscle cell relaxation and dilationof veins and arteriesCopyright 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins 24. Nesiritide: Core Drug Knowledge (cont.) Contraindications and precautions Cardiogenic shock, hypersensitivity, and systolicblood pressure less than 90 mm Hg Adverse effects Hypotension, injection site reactions, rash, sweating,itching, leg cramps, anemia, confusion,lightheadedness, dimmed vision, increased creatininelevels, cough, apnea, and hemoptysis Serious side effects are all cardiac. Drug interactions Is known to interact with some drugsCopyright 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins 25. Nesiritide: Core Patient Variables Health status Assess status of CHF and clinical symptoms. Life span and gender Determine age. Environment Administer the drug only where patients can receivecontinuous cardiac monitoring.Copyright 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins 26. Nesiritide: Nursing Diagnoses andOutcomes Decreased Cardiac Output related to altered strokevolume Desired outcome: drug therapy with nesiritide willincrease cardiac output.Copyright 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins 27. Nesiritide: Planning and Interventions Maximizing therapeutic effects Nesiritide must be reconstituted and then furtherdiluted for infusion. Use the reconstituted nesiritide solution within 24Copyright 2012 Wolters Kluwer Health | Lippincott Williams & Wilkinshours. Minimizing adverse effects Monitor the patients cardiac response to nesiritidetherapy by keeping the patient on a continuouscardiac monitor during therapy. Monitor the patients blood pressure and pulse. 28. Nesiritide: Teaching, Assessment, andEvaluations Patient and family education Teach patients and families the purpose of nesiritideCopyright 2012 Wolters Kluwer Health | Lippincott Williams & Wilkinstherapy. Instruct patients to notify a nurse if the IV insertionsite becomes sore or itches. Ongoing assessment and evaluation Monitor plasma brain natriuretic peptideconcentrations and plasma aldosterone levels, bothof which should decrease in response to the drug. 29. Copyright 2012 Wolters Kluwer Health | Lippincott Williams & WilkinsQuestion What is a significant side effect of nesiritide infusion? A. Respiratory depression B. Change in level of consciousness C. Seizures D. ECG changes 30. Copyright 2012 Wolters Kluwer Health | Lippincott Williams & WilkinsAnswer D. ECG changes Rationale: Significant ECG or rhythm changes canoccur from nesiritide therapy. Therefore, administerthe drug only where patients can receive continuouscardiac monitoring, such as in an intensive care orcardiac care unit.