Heart Failure: An Overview

Heart Failure (HF) Overview

• HF is a clinical syndrome where impaired cardiac pumping or filling occurs
• HF was formerly called congestive heart failure (CHF)
• In HF, the heart cannot produce adequate cardiac output (CO) to meet metabolic needs
• In Canada, HF affects 1 in 5 people over 40 years old
• Primary risk factors for HF are coronary artery disease and hypertension
• Diabetes mellitus also predisposes individuals to HF, regardless of CAD or hypertension
• Other risk factors include tobacco smoking, obesity, and high serum cholesterol levels
• HF is not a disease, but a syndrome characterized by ventricular dysfunction
• HF symptoms include reduced exercise tolerance, diminished quality of life, and shortened life expectancy
• HF is a major global health problem projected to increase, particularly concerning Canada's aging population

Etiology and Pathophysiology

• Causes of HF are divided into primary and precipitating subgroups
• HF is described as being accompanied by reduced ejection fraction (HFrEF), mid-range ejection fraction (HFmEF), or preserved ejection fraction (HFpEF)
• Ejection fraction (EF) refers to the percentage of total blood in the heart that is pumped out with each heartbeat

Heart Failure Types

Heart Failure with Reduced Ejection Fraction (HFrEF)

• HFrEF is the most common type
• HFrEF results from the heart's inability to pump blood effectively
• Its causes include are impaired contractile function (e.g., MI), increased afterload (e.g., hypertension), cardiomyopathy, and mechanical abnormalities (e.g., valvular disease)
• In HFrEF, the left ventricle loses its ability to eject blood forward through the aorta, resulting in normal EF that is higher than 55% of the ventricular volume, and in patients with HFrEF an EF of 40% or lower

Heart Failure with Preserved Ejection Fraction (HFpEF)

• HFpEF is marked by the inability of ventricles to relax and fill during diastole
• The stroke volume and CO decrease as a result of diastole
• Diagnosis is based on the presence of HF symptoms with an EF of 50% or greater
• In HFpEF, ventricles are poorly compliant, which keeps EF high, and results in venous engorgement in both pulmonary and systemic vascular systems
• HFpEF is often caused by left ventricular hypertrophy from hypertension (most common), myocardial ischemia, valve disease (e.g., aortic, mitral), or cardiomyopathy

Heart Failure with Mid-Range Ejection Fraction (HFmEF)

• HFmEF represents different characteristics of HF with a left ventricular EF of 41 to 49%
• Recovered EF is a new term to define individuals who originally had HF with reduced EF but with treatment now have an EF greater or equal to 40%

Mixed Heart Failure

• Mixed heart failure occurs in disease states like dilated cardiomyopathy
• Individuals with it have poor systolic function further compromised by dilated left ventricular walls unable to relax and fill effectively
• Poor EFs (<35%) are a marker of it
• Individuals also experience high pulmonary pressure and biventricular failure
• Both ventricles may be dilated and have poor filling and emptying capacity

Body Responses to Heart Failure

• Patients with HF of any type have low systemic blood pressure (BP) and low CO
• The body responds by mobilizing its compensatory mechanisms to maintain CO and BP
• The main compensatory mechanisms include sympathetic nervous system (SNS) activation, neurohormonal responses, ventricular dilation, and ventricular hypertrophy.

Sympathetic Nervous System (SNS) Activation

• SNS activation is the first and least effective mechanism
• This is marked by the release of catecholamines (epinephrine and norepinephrine), increased heart rate (HR), increased myocardial contractility, and increased peripheral vasoconstriction
• These mechanisms increase the workload of the failing heart and O₂ needs over time

Neurohormonal Responses

• As CO falls, blood flow to the kidneys decreases, triggering the kidneys to release renin
• This response is known as the renin-angiotensin-aldosterone system (RAAS)
• RAAS causes sodium and water retention and increased peripheral vasoconstriction
• Low CO also causes a decrease in cerebral perfusion, which secretes antidiuretic hormone (ADH)
• ADH causes increased water reabsorption in the kidneys, leading to water retention and increased blood volume
• Renin and ADH stimulate vascular smooth muscles, causing arterial vasoconstriction, and increasing cardiac contractility and hypertrophy

Ventricular Dilation

• Ventricular dilation involves the enlargement of the heart chamber
• Ventricular dilation occurs when pressure in the left ventricle is elevated and is adaptive
• This adaptive mechanism becomes inadequate, and CO decreases

Ventricular Hypertrophy

• Ventricular hypertrophy involves an increase in muscle mass
• It is the increase in muscle mass and cardiac wall thickness in response to chronic dilation, and develops slowly
• Ventricular hypertrophy helps increase contractions and CO initially
• Ventricular hypertrophy leads to poor contractility, higher O₂ needs, poor coronary artery circulation, and risk for ventricular dysrhythmias over time

Types of Heart Failure

• Heart failure (HF) is usually biventricular
• One ventricle may become dysfunctional before the other
• The most common form of heart failure (HF) is left-sided, arising from left ventricular dysfunction
• Left-sided HF is when blood backs up into the left atrium and the pulmonary veins
• Pulmonary congestion results
• The resulting edema manifests as pink, frothy sputum
• In right-sided HF the primary cause is left-sided heart failure
• Blood backs up into the right atrium and venous systemic circulation
• Right-sided HF causes jugular venous distension, hepatomegaly, splenomegaly, vascular congestion of the gastrointestinal (GI) tract, and peripheral edema

Clinical Manifestations: Acute Decompensated Heart Failure

• Regardless of etiology, acute decompensated heart failure (ADHF) typically manifests as pulmonary edema
• Pulmonary edema is abnormal, life-threatening fluid accumulation in the alveoli and interstitial spaces of the lungs
• Pulmonary edema is progressive
• The early signs of pulmonary edema are an increase in respiratory rate and a decrease in PaO2
• Later signs involve tachypnea, shortness of breath disproportionate to activity level, and respiratory acidemia
• General signs include anxiety, pale or cyanotic skin, cool and clammy skin, dyspnea, orthopnea, wheezing, cough, crackles, and tachycardia

Symptoms of Left Sided Heart Failure

• Left ventricular heaves
• Cheyne-Stokes respirations
• Pulsus alternans
• Increased HR
• Displaced point of maximal impulse
• Decreased PaO2
• Crackles
• S3 and S4
• Fatigue
• Dyspnea
• Orthopnea
• Dry, hacking cough
• Pulmonary edema
• Nocturia
• Paroxysmal nocturnal dyspnea

Symptoms of Right Sided Heart Failure

• Right ventricular heaves
• Murmurs
• Peripheral edema
• Weight gain
• Increased heart rate
• Edema
• Ascites
• Anasarca
• Jugular venous distention
• Hepatomegaly
• Right-sided pleural effusion
• Fatigue
• Dependent edema
• Right upper quadrant pain
• Anorexia and Gl bloating
• Nausea

Clinical Manifestations: Chronic Heart Failure

• Chronic HF is marked by fatigue, dyspnea, orthopnea, and paroxysmal nocturnal dyspnea
• A persistent, dry cough unrelieved with position change or over-the-counter cough suppressants can occur
• Additional symptoms may involve tachycardia, dependent edema, nocturia, skin changes
• Skin changes may include dusky, cool, damp skin, and shiny/swollen lower extremities, diminished or absent hair growth, and pigment changes

Additional Symptoms of Heart Failure (Cont.)

• Behavioral changes, which may include restlessness, confusion, and decreased memory
• Chest pain (angina)
• Sudden weight gain of >1.5 kg over 1 to 2 days or >2.5 kg in a week may indicate an exacerbation of HF
• Progressive weight gain is another symptom
• Renal failure leading to fluid retention
• Abdominal fullness
• Anorexia and/or nausea

Complications of Heart Failure

• Pleural effusion caused by increased pressure in pleural capillaries
• Dysrhythmias develop from enlargement and stretching of the heart chambers
• This heart pathology promotes thrombus/embolus formation which increasing the risk for stroke
• Left ventricular thrombus from ventricle enlargement and decreased CO
• Venous congestion progresses into Hepatomegaly and cirrhosis
• Decreased perfusion progressing into Renal insufficiency or failure

Classification of Heart Failure

• Classification is by the New York Heart Association Functional Classification of HF
  • Class I patients have no limited activity
  • Class II patients have slight limitations
  • Class III patients have marked limitations
  • Class IV patients have an inability to carry out any physical activity without discomfort

Diagnostic Studies

• Diagnosing HF can be difficult
• The primary goal of testing: determine and treat the underlying cause
• Diagnostics: review the patient's history and physical examination results to treat the underlying cause
• If HF is likely, get a chest X-ray, 12-lead electrocardiogram (ECG), echocardiogram, and lab studies(cardiac enzymes, BNP, etc)

Nursing and Interprofessional Management: Acute Decompensated Heart Failure (ADHF)

Acute Decompensated Heart Failure (ADHF) Management

Decreasing Intravascular Volume

• This reduces venous return and preload
• The overfilled ventricle contracts more efficiently and improves CO
• Loop diuretics (e.g., furosemide/Lasix) help get fluids of the patient
• Ultrafiltration via hemodialysis or central venous access when diuretics are not enough

Decreasing Venous Return (Preload)

• This reduces the amount of volume returned to the left ventricle during diastole
• High Fowler's position with feet horizontal or dangling assists with this process
• IV nitroglycerin (vasodilator)
• Furosemide/Lasix (reduces intravascular volume)

Decreasing Afterload

• This reduces the resistance that ventricle needs to pump against, and improves CO and decreases pulmonary congestion
• Careful monitoring of vital signs is crucial.

Improving Gas Exchange and Oxygenation

• Supplemental oxygen if oxygen saturation <90%
• IV Morphine sulphate helps reduces preload and afterload; and decreases myocardial O₂ demands
• Noninvasive ventilatory support (BiPAP) is necessary in severe pulmonary edema.
• Intubation or mechanical ventilation may be indicated as well

Nursing and Interprofessional Management of Chronic Heart Failure

• For patients that don't respond to traditional pharmacotherapy, improve cardiac function with inotropic therapy: Dobutamine or milrinone
  • Dobutamine/Milrinone is typically reserved for hemodynamically unstable patients
  • Hemodynamic monitoring
• With patient anxiety, integrate therapeutic distractions, imagery and sedative medications (e.g., morphine sulphate)
  • Monitor for respiratory depression

Interprofessional Care: Chronic Heart Failure

• The main treatment goals entail treating the underlying cause, maximizing CO, and reducing symptoms

Treatment Goals

• Referral to multidisciplinary clinic or specialist care for HF
• An interprofessional team can provide self-management coaching and assessment for more advanced therapies
• Some care centers, the use of telehealth technologies are used to monitor the patient remotely

Self Management

• Use supplemental O₂ as prescribed, per SP02
• Understand that HF is a chronic condition
  • Reduce risk of decompensation
  • Quickly recognize S/S
• Follow a routine 3-5 times per week for 30-45 min
• Individualize the routines as needed
• Ask about your care team about cardiac rehabilitation

Device Therapy

• Cardiac resynchronization therapy (CRT)
• Implantable cardioverter-defibrillator
• Mechanical circulatory support
  • Intra-aortic balloon pump (IABP)
  • Extra-corporeal membrane oxygenation (ECMO)
  • Ventricular assist device (VAD)
• Heart transplantation

Medication Therapy

• Goals for medication therapy include identify type of HF and underlying cause
• Additional goals: correct any sodium/water retention, reduce pressure on the heart, improve contraction and control any known contributors
• Improve symptoms and reduce morbidity/mortality
• Common medications include:
  • Diuretics
  • ACE inhibitors
  • Β--Adrenergic blockers
  • Mineralocorticoid receptor antagonists
  • Inotropic medications

Diet and Lifestyle Recommendations

• Diatery recommendations should consider cultural
• Lifestyle modifications should focus on cultural factors
• Follow DASH diet
• Reduce sodium intake(<2–1.5g)
• Read labels to determine sodium content
• Use fresh fruits and uncooked food
• When eating out, ask about sodium content when consuming fluids
• Encourage a maximum water allowance of ~2L/day
• If thirsty, eat something or chew gum, weigh self
  • Contact provider for a 2lbs increase over 24 hours

Long Term Planning

Advanced Care Planning

• Develop realistic goals for patient in light of current prognosis of a poor outcome
• Quality of life should dictate planning
• Collaborate with others/community resources as indicated
• Plan for end-of-life and discuss with family

Nursing Management: Assessment

• Important health history with medications
• Assess current S/S
  • Fatigue
  • Depression
  • Anxiety
  • Nausea
  • Anorexia
  • Weight gain
  • Swelling
  • Nocturia
  • Dyspnea
  • Cough, chest pain/heaviness
  • Palpitations
  • Dizziness
• What objective data should the nurse be reviewing?
  • Cool, diaphoretic skin/cyanosis
  • Respiratory effort-crackles and tachypnea
  • Cardio-murmurs, PMI, S3/4 sounds
  • GI complaints
  • Restlessness

Nursing Implementation: Planning

• Work as a team to develop a realistic care plan or overall goals
  • Decrease overall S/S
  • Lower peripheral edema
  • Goal is to improve exercise tolerance
  • Improve adherence
    • Review potential risks and complications
• Nursing Management: Chronic Heart Failure*

Health Promotion

• Prevent development of HF with careful care plans and monitor patients with underlying conditions
  • Valvular disease, hypertension, lipid issues
• Advocate a balanced diet
• Encourage exercise within safe health guidelines
• Early detection to prevent hospitalization
• Provide patient with specific teaching materials (meds. weight monitoring and exercises)
• When diagnosed, care should be focused on slowing disease
• Support patient centered choices
• Reinforce lifestyle changes as directed
• **

Acute Care

• Goals are to achieve quality of life balance and management skills
• Self-management tools like daily weights/exercises
• **

Ambulatory/Home Care

• Support/Educate family and caregivers regarding the disease
• Patients should be aware of physiological complications and S/S
• Provide a safe environment
• Collaborate with community resources