Heart Failure

Perfusion in Relation to Heart Failure

Objectives

  • Expand on the topic of perfusion in relation to heart failure.

  • Recognize when an individual has compromised perfusion.

  • Provide appropriate nursing and collaborative interventions to optimize perfusion in a patient with heart failure.

  • Discuss commonly used drug groups utilized for perfusion in relation to their actions, uses, side effects, and nursing implications.

  • Exemplar: Heart Failure.

Review of Key Concepts

  1. Preload

    • Definition: The degree of myocardial fiber stretch at the end of diastole and just before contraction.

  2. Afterload

    • Definition: The resistance against which the heart must pump.

  3. Contractility

    • Definition: The ability of the heart's atria and ventricles to shorten their length in response to electrical impulses, which causes pressure to propel blood forward.

  4. Ejection Fraction

    • Definition: The percentage of blood ejected from the heart during systole. The normal range is 50-70%.

Preload and Afterload

Preload

  • Definition: The volume of blood in the ventricles at the end of diastole (also referred to as end diastolic pressure).

  • Factors leading to increased preload include:

    • Hypervolemia

    • Regurgitation of cardiac valves

    • Heart Failure

Afterload

  • Definition: The resistance the left ventricle must overcome to circulate blood.

  • Factors leading to increased afterload include:

    • Hypertension

    • Vasoconstriction

  • Increased afterload results in increased cardiac workload.

Heart Failure Basics

  • Heart failure, also referred to as pump failure, is characterized by the heart's inability to work effectively as a pump.

  • It is a chronic condition that frequently has acute episodes (exacerbations), often leading to hospitalization.

  • Heart failure can be life-threatening and is the most common reason for hospitalization in patients over 65 years old in the United States.

  • A common contributor to heart failure is valve disease.

Types of Heart Failure

Major Types

  1. Left-sided Heart Failure

    • Systolic Heart Failure:

      • Characterized by decreased ejection fraction (EF).

      • Known as “Forward Failure.”

      • Increased risk for sudden death.

      • Clinical manifestations include inadequate tissue perfusion leading to systemic congestion.

    • Diastolic Heart Failure:

      • Occurs when the left ventricle cannot relax due to stiffening during diastole.

      • Clinical manifestations are similar to those of systolic dysfunction.

  2. Right-sided Heart Failure:

    • Caused by the right ventricle’s inability to empty fully, resulting in increased volume and pressure in the venous system, causing peripheral edema.

Compensatory Mechanisms in Heart Failure

When cardiac output is insufficient to meet the body's demands, several mechanisms operate to increase cardiac output:

  • Sympathetic Nervous System Stimulation:

    • Increased catecholamines as a result of hypoxia, leading to an increase in heart rate and a decrease in blood pressure through vasoconstriction.

  • Renin-Angiotensin System Activation:

    • Reduced blood flow to the kidneys activates the angiotensin system, resulting in vasoconstriction and increased preload and afterload.

  • Chemical Responses (BNP):

    • Brain Natriuretic Peptide (BNP) is produced and released by the ventricles when they stretch in response to fluid overload from heart failure.

  • Decreased Cardiac Output Effects:

    • The brain releases vasopressin, which further increases fluid retention.

  • Myocardial Hypertrophy:

    • Enlargement of the myocardium causes thickening of the heart walls to provide more muscle mass, enabling more forceful contractions and an increase in cardiac output.

    • However, collateral circulation cannot form quickly enough to compensate for muscular hypertrophy, which can be damaging.

Clinical Manifestations of Left-Sided Heart Failure

  • Weakness

  • Fatigue

  • Dizziness

  • Acute confusion (due to low blood flow)

  • Extra heart sounds

  • Pulmonary congestion

    • Frothy, pink-tinged sputum

  • Breathlessness and exertional dyspnea

  • Orthopnea

  • Oliguria

  • Nocturia

Clinical Manifestations of Right-Sided Heart Failure

  • Jugular vein distention

  • Increased abdominal girth

  • Dependent edema

  • Hepatomegaly

  • Ascites

  • Weight is the most reliable indicator of fluid gain/loss; typical weights to monitor include:

    • Rapid weight gain of 3 lbs in one week or 1-2 lbs overnight indicates worsening heart failure.

  • Cor Pulmonale:

    • Right-sided heart failure due to pulmonary hypertension.

Diagnostics for Heart Failure

Laboratory Tests

  • Electrolytes

  • Hemoglobin and Hematocrit

  • BNP

  • Urinalysis (indicators can include proteinuria or high specific gravity)

  • Arterial Blood Gases (ABGs)

Imaging Tests

  • Chest X-ray (CXR)

  • Echocardiography (considered the best diagnostic tool)

  • Electrocardiogram (ECG)

  • Pulmonary artery catheterization (PAP/PAWP are elevated in left heart failure)

Priority Collaborative Problems

  • Decreased gas exchange due to ventilation/perfusion imbalance.

  • Potential for decreased perfusion due to inadequate cardiac output.

  • Potential for pulmonary edema resulting from left-sided heart failure.

Treatment Considerations

Gas Exchange

  • Promote oxygenation and gas exchange through:

    • Ventilation assistance

    • Monitoring respiratory rate every 1 to 4 hours

    • Auscultating breath sounds every 4 to 8 hours

    • Positioning the patient in high Fowler’s if dyspneic

    • Maintaining oxygen saturation of at least 90%.

Treatment for Perfusion

  1. Improve/increase cardiac pump effectiveness:

    • Address problems with:

      • Preload

      • Afterload

      • Contractility

Preload

  • Problem: Increased preload.

  • Solution: Decrease systemic volume and pressure in the ventricles.

  • Methods include:

    • Morphine

    • Oxygen

    • Diuretics

Afterload

  • Problem: Increased afterload.

  • Solution: Decrease afterload.

  • Methods include:

    • First-line treatment with ACE inhibitors. Side effects include:

    • [Insert Side Effects Here]

    • Second-line treatment with ARBs (angiotensin receptor blockers). Side effects include:

    • [Insert Side Effects Here]

Contractility

  • Problem: Decreased contractility.

  • Solution: Increase contractility.

  • Method includes:

    • Digoxin (as per reference on page 681).

Nutritional Therapy:

  • Limit daily sodium intake to 2-3 grams as prescribed.

  • Limit daily fluid intake to 2 liters.

  • Promote daily weights to monitor fluid status:

    • 1 kg of weight gained = 1 L of fluid retained.

    • Rapid weight gain (3 lbs in a week or 1-2 lbs overnight) could indicate worsening heart failure.

  • Teach the patient or caregiver to report the following symptoms immediately:

    • Rapid weight gain of 3 lbs within a week or significant overnight weight gain

    • Decrease in exercise tolerance lasting 2 to 3 days

    • Cold symptoms (cough) lasting over 3 to 5 days

    • Excessive awakening at night to urinate

    • Development of dyspnea or angina at rest or worsening angina

    • Increased swelling in the feet, ankles, or hands

  • Reference Table 32.4 for MAWDS education (Medication, Activity, Weight, Diet, Symptoms).

Advanced Treatments

  • Heart transplantation

  • Devices such as Pacemakers, Cardioverter/Defibrillators, Cardiac Resynchronization Therapy (CRT)

  • Ventricular Assist Devices (VADs)

  • Endoventricular circular patch cardioplasty

  • Refer to core measures for further guidelines.

Case Study Analyses

Case Study 1

  • A 53-year-old client, weighing 237 lbs and standing 5'8”, was admitted for recurrent exacerbation of heart failure. He is on oxygen therapy at 2 L via nasal cannula. When the nurse enters, the client is sitting on the bed, sweating, and experiencing shortness of breath. After using the bathroom, his nasal cannula is not on.

  • Question 1: Which action will the nurse take?

    • Options:

      • A: Obtain vital signs.

      • B: Replace the nasal cannula.

      • C: Sit him up in a bedside chair.

      • D: Call the Rapid Response Team.

  • Answer: B: Replace the nasal cannula to restore supplemental oxygen before obtaining vital signs.

Case Study 2

  • Fifteen minutes after replacing the nasal cannula, the client’s oxygen saturation reaches 97%.

  • Question 2: What is the appropriate nursing action?

    • Options:

      • A: Continue assessment.

      • B: Encourage deep breathing.

      • C: Contact the health care provider.

      • D: Increase the oxygen to 5 L per nasal cannula.

  • Answer: A: Continue assessment since the patient's oxygen saturation is acceptable and he is no longer short of breath.

Case Study 3

  • Assessment findings include the presence of jugular venous distention, 2+ edema in feet and ankles, swollen hands and fingers, distended abdomen, bibasilar crackles on auscultation, and productive cough with pink-tinged sputum.

  • Question 3: What condition is most likely based on these results?

    • Options:

      • A: Biventricular failure.

      • B: Class IV heart failure.

      • C: Left-sided heart failure.

      • D: Right-sided heart failure.

  • Answer: A: Biventricular failure, indicated by features of both right-sided and left-sided heart failure.

Case Study 4

  • The next day, the client develops shortness of breath, fatigue, and tachycardia.

  • Question 4a: How does the nurse interpret these findings?

  • Question 4b: Which nursing interventions are appropriate at this time?

  • Answer:

    • 4a: The patient experiences fatigue from excessive exertion.

    • 4b: Implement energy management strategies and provide physical and emotional rest. Arrange nursing care to afford periods of rest, assist the client where necessary, and observe/document the client’s responses throughout.

Case Study 5

  • During the evening shift, a bedside echocardiogram reveals an ejection fraction of 30%.

  • Question: Which medication does the nurse anticipate may be prescribed?

    • Options:

      • A: Adenosine

      • B: Lisinopril

      • C: Digoxin

      • D: Lidocaine

      • E: Furosemide

  • Answer: B, C, E: Lisinopril (ACE inhibitor), Digoxin (nitrate), and Furosemide (diuretic) represent the common drug classes utilized in managing heart failure. Adenosine and Lidocaine are inappropriate for this scenario.