NUR246 TOPIC 8 CHRONIC HEART FAILURE

Managing Chronic Diseases – Part 2: Lecture Notes

Heart Failure Overview

  • Definition:

    • An abnormal clinical syndrome characterized by inadequate cardiac pumping or filling, resulting in insufficient blood supply and oxygen to tissues.

    • Previously referred to as congestive heart failure (CHF).

Risk Factors for Heart Failure

  • Primary Risk Factors:

    • Hypertension (HTN)

    • Coronary Artery Disease (CAD)

  • Contributing Risk Factors:

    • Advanced age

    • Diabetes

    • Tobacco use

    • Obesity

    • High serum cholesterol

Aetiology of Heart Failure

  • Primary Causes:

    • Conditions that directly damage the heart, interfering with mechanisms that regulate cardiac output (CO).

  • Precipitating Causes:

    • Conditions that increase the workload of the ventricles, leading to heart failure.

Pathophysiology of Heart Failure

  • Systolic Heart Failure:

    • Defined as the inability to pump blood effectively due to:

    • Impaired contractile function

    • Increased afterload

    • Cardiomyopathy

    • Mechanical abnormalities

    • Decreased left ventricular ejection fraction (EF).

  • Heart Failure with Preserved Ejection Fraction (HFpEF) or Diastolic Heart Failure:

    • Impaired ability of ventricles to relax and fill during diastole, leading to decreased stroke volume and CO.

    • Can result from left ventricular hypertrophy due to hypertension, myocardial infarction (MI), valve disease, or cardiomyopathy.

    • Many patients may not have identifiable heart disease.

  • Mixed Heart Failure:

    • Characteristics include mixed systolic and diastolic failure.

    • Seen in states such as dilated cardiomyopathy (DCM), poor EF (< 35%), and high pulmonary pressures.

    • Biventricular failure with both ventricles being dilated and having poor filling and emptying capacity.

General Pathophysiology in Heart Failure

  • Ventricular failure leads to:

    • Low blood pressure (BP)

    • Low CO

    • Poor renal perfusion

    • Abrupt or subtle onset of symptoms.

  • Compensatory mechanisms are mobilized to maintain adequate CO.

Compensatory Mechanisms in Heart Failure

  • Activation of the Sympathetic Nervous System (SNS):

    • The first and least effective compensatory mechanism.

    • Results in release of catecholamines (adrenaline and noradrenaline), leading to:

    • Increased heart rate

    • Increased myocardial contractility

    • Peripheral vasoconstriction.

    • Initially beneficial but can become harmful over time.

  • Neurohormonal Responses:

    • Kidneys release renin, initiating the Renin-Angiotensin-Aldosterone System (RAAS).

    • Posterior pituitary gland secretes Antidiuretic Hormone (ADH).

    • Endothelin released by vascular endothelial cells acts as a vasoconstrictor.

    • Continuous activation of the RAAS and SNS can lead to ventricular remodeling.

Ventricular Remodeling

  • Results from continuous activation of the SNS and neurohormonal systems.

  • Leads to:

    • Hypertrophy of ventricular myocytes (muscle cells).

    • Ventricles enlarge but become less efficient at pumping.

    • Can lead to life-threatening dysrhythmias and sudden cardiac death.

Types of Ventricular Changes

  • Dilation:

    • Enlargement of heart chambers due to elevated pressures in the left ventricle.

    • Initially effective but can become inadequate over time resulting in decreased cardiac output (CO).

  • Hypertrophy:

    • Increase in muscle mass and thickness of heart walls, manageable initially but leads to poor contractility, increased oxygen needs, and risk of ventricular dysrhythmias over time.

Counter-Regulatory Mechanisms

  • Nitric Oxide (NO):

    • Released from vascular endothelium in response to compensatory mechanisms.

    • NO promotes vasodilation and reduces afterload, aiding heart function.

    • Differentiates between cardiac compensation (adequate compensatory mechanisms) and decompensation (inadequate compensatory mechanisms).

Heart Failure Types

  • Left-Sided Heart Failure:

    • The most common type, results from left ventricular dysfunction.

    • Blood backs up into the left atrium and pulmonary veins, causing increased pulmonary pressure.

    • Leads to pulmonary congestion and edema.

  • Right-Sided Heart Failure:

    • Results from right ventricular dysfunction.

    • Blood backs up into the right atrium and venous circulation, leading to symptoms such as:

    • Jugular venous distension

    • Hepatomegaly (enlargement of the liver)

    • Splenomegaly

    • Vascular congestion in gastrointestinal tract

    • Peripheral edema.

    • Commonly caused by left-sided heart failure but may also occur from acute conditions such as right ventricular infarction, pulmonary embolism (PE), or cor pulmonale.

Chronic Heart Failure: Signs and Symptoms

  • Common symptoms include:

    • Fatigue

    • Dyspnea (shortness of breath)

    • Orthopnea (difficulty breathing when lying down)

    • Paroxysmal nocturnal dyspnea (sudden nighttime breathlessness)

    • Cough

    • Tachycardia (rapid heart rate)

    • Oedema (fluid retention) occurring in:

    • Dependent areas (legs, ankles)

    • Liver, abdominal cavity, lungs.

    • Oedema may present as pitting and can be indicative of worsening heart failure.

    • Sudden weight gain of >3 lbs (1.4 kg) in 2 days might indicate acute decompensated heart failure (ADHF).

  • Additional signs may include:

    • Nocturia (frequent nighttime urination)

    • Skin changes

    • Behavioral changes

    • Chest pain

    • Weight changes.

Heart Failure Complications

  • Possible complications include:

    • Pleural effusion (fluid between lungs and chest wall)

    • Dysrhythmias (both atrial and ventricular)

    • Left ventricular thrombus (blood clot)

    • Hepatomegaly

    • Renal failure (kidney dysfunction).

Heart Failure Diagnostic Studies

  • Goal: Identify and treat underlying causes of heart failure.

    • Diagnostic Procedures:

    • Endomyocardial biopsy (EMB)

    • Measurement of ejection fraction (EF) via echocardiography or nuclear imaging.

    • Chest X-ray for heart size and fluid presence.

    • ECG (Electrocardiogram) to detect electrical activity.

    • Stress testing.

    • Cardiac catheterization for direct pressures and chamber assessment.

    • Laboratory studies including Brain Natriuretic Peptide (BNP or NT-proBNP), arterial blood gases (ABGs).

Interprofessional Care for Acute Decompensated Heart Failure (ADHF)

  • Monitoring and Assessment:

    • Continuous monitoring of vital signs, oxygen saturation, and urinary output.

    • Hemodynamic monitoring if patient is unstable.

    • Supplemental oxygen required for low oxygen saturation.

    • Mechanical ventilation may be necessary.

    • Positioning the patient in High Fowler’s position (sitting up) to ease breathing.

  • Therapeutic Interventions:

    • Ultrafiltration: Used for patients with volume overload resistant to diuretics.

    • Circulatory Assist Devices: Indicated for patients with deteriorating heart failure, such as:

    • Intra-aortic balloon pump (IABP)

    • Ventricular assist devices (VADs).

    • Psychological support for anxiety or depression is crucial.

Medication Therapy for ADHF

  • Diuretics:

    • Used to reduce volume overload (preload).

    • Examples: Frusemide (furosemide), Bumetanide, Spironolactone.

  • Vasodilators:

    • Help decrease circulating blood volume and improve coronary artery circulation.

    • Examples: IV Glyceryl Trinitrate (GTN), Sodium Nitroprusside, Nesiritide.

  • Morphine:

    • Reduces preload and afterload, providing relief from dyspnea and anxiety.

  • Positive Inotropes:

    • Categories include:

    • β-adrenergic agonists (Dopamine, Dobutamine)

    • Phosphodiesterase inhibitors (Milrinone)

    • Digitalis (monitor for toxicity).

Interprofessional Care for Chronic Heart Failure

  • Main Treatment Goals:

    • Treat underlying causes and contributing factors.

    • Maximize cardiac output.

    • Alleviate symptoms.

    • Improve ventricular function.

    • Enhance quality of life.

    • Preserve function of target organs and reduce mortality/morbidity.

  • Oxygen Therapy:

    • Prescribed to alleviate dyspnea and fatigue.

  • Physical and Emotional Rest:

    • Important to conserve energy and reduce oxygen demands.

  • Structured Exercise Program:

    • Implemented gradually as tolerated.

  • Cardiac Resynchronization Therapy (CRT):

    • Biventricular pacing for qualified patients.

Medication Therapy for Chronic Heart Failure

  • Standard medications include:

    • Diuretics: Manage fluid retention.

    • RAAS inhibitors: ACE inhibitors (ending in ‘-pril’), Angiotensin II receptor blockers (ending in ‘-sartan’), Aldosterone antagonists (ending in ‘-one’).

    • β-adrenergic blockers: (ending in ‘-olol’).

    • Vasodilators: such as nitrates.

    • Positive inotropic agents: Including digitalis (monitor for toxicity).

Nutritional Therapy for Chronic Heart Failure

  • Recommendation for a low-sodium diet, typically around:

    • Dietary Approaches to Stop Hypertension (DASH) diet as a guideline.

    • Sodium restriction of about 2 g/day.

    • Fluid restriction might be indicated, with less than 2 L/day if required.

    • Daily weights to monitor for sudden weight gain, which could indicate fluid retention.

Nursing Assessment for Heart Failure

  • Subjective Data:

    • Important health history: Conditions like CAD, HTN, cardiomyopathy, diabetes, etc.

    • Medications taken and adherence.

    • Health perception and functional health patterns related to fatigue, and depression.

    • Nausea, vomiting, abdominal bloating noted under nutritional-metabolic.

    • Changes in activity, sleep, cognitive conditions.

  • Objective Data:

    • Integumentary Signs: Cooling skin, cyanosis or pallor, peripheral edema.

    • Respiratory Signs: Tachypnea, crackles, possible frothy sputum.

    • Cardiovascular Signs: Tachycardia, heart sounds (S3 and S4), jugular venous distention.

    • Gastrointestinal Signs: Assess for distension or mechanical symptoms.

    • Neurological: Check for restlessness or confusion.

  • Diagnostic Findings:

    • Altered serum electrolytes, elevated urea, creatinine, BNP levels, chest X-ray typically revealing cardiomegaly, and echocardiogram results suggesting diastolic failure or limited ejection fraction.

Nursing Management for Chronic Heart Failure

  • Planning Goals:

    • Decrease symptoms and peripheral edema.

    • Increase exercise tolerance.

    • Ensure adherence to the medical regimen.

    • Prevent complications related to HF.

  • Implementation Strategies:

    • Promote health and self-management:

    • Manage episodes of acute decompensated heart failure (ADHF).

    • Educate on the progressive nature of HF and establish realistic treatment plans.

    • Maintain support systems, reduce anxiety, and encourage healthy behavior modifications.

  • Home Care and Patient Education:

    • Patients and caregivers should understand physiological changes and adapt to them.

    • Management of symptoms, medication education, dietary recommendations, and activity/rest plans discussed.

    • Highlight the importance of ongoing assessments via monitoring vital signs and weights to prevent further hospitalizations.

Heart Failure Nurse – Role, Skills, Qualifications, and Challenges

Role:

  • Manages patients with heart failure in hospital and community settings.

  • Monitors symptoms, vital signs, fluid status, and medication adherence.

  • Provides patient education on lifestyle modifications, diet, exercise, and self-monitoring.

  • Coordinates care with cardiologists, GPs, and allied health professionals.

Skills:

  • Clinical assessment: Heart sounds, oedema, weight monitoring, blood pressure, and fluid balance.

  • Patient education: Salt restriction, fluid management, medication adherence, recognizing exacerbations.

  • Communication: Collaborates with multidisciplinary team and supports patients and families.

  • Critical thinking: Adjusting care plans based on patient condition and response.

Qualifications:

  • Registered Nurse (RN) with AHPRA registration.

  • Postgraduate training or certification in cardiology or heart failure management is advantageous.

  • Experience in cardiac care, chronic disease management, or community nursing.

Challenges:

  • Managing patients with complex comorbidities (e.g., diabetes, CKD).

  • Ensuring adherence to medications and lifestyle changes.

  • Early recognition and management of exacerbations to prevent hospital readmissions.