Heart Failure

Definition and Pathophysiology of Heart Failure

• Heart failure is a complex and progressive clinical syndrome characterized by abnormalities in the structure or function of the heart.

• These abnormalities result in two primary physiological consequences:

  • Decreased cardiac output.

  • Increased pressure within the heart during periods of rest or stress.

• The condition occurs when the heart is unable to meet the specific needs of the systemic circulatory system.

• Mechanisms of failure include:

  • Improper filling of the ventricles (diastolic dysfunction).

  • Inadequate ejection of blood into the systemic system (systolic dysfunction).

Etiology and Contributing Conditions

• Heart failure arises from various cardiopulmonary conditions that alter cardiac structure or function:

  • Coronary Artery Disease (CAD).

  • Myocardial Infarction (MI).

  • Diabetes.

  • Hypertension.

  • Uncontrolled arrhythmias.

  • Valvular disease.

  • Myocarditis.

  • Congenital heart disease.

• Heart failure can also occur in the absence of primary structural or functional cardiac changes due to:

  • Thyrotoxicosis.

  • Anemia.

  • Thiamine deficiencies.

  • Pregnancy.

Risk Factors and Comorbidities

• Identified risk factors for the development of heart failure include:

  • Family history of heart disease.

  • Chronic pulmonary disease.

  • Chronic infection or inflammation.

  • Diabetes mellitus.

  • Obesity and metabolic diseases.

  • Alcohol abuse.

  • History of treatment with cardiotoxic agents, such as anthracyclines.

• Comorbidities significantly complicate the management of heart failure, with over $50\%$ of clients having at least one comorbid condition:

  • Cardiac: Atrial fibrillation (Afib), hypertension.

  • Non-cardiac: Obesity, chronic kidney disease, diabetes mellitus, anemia, iron deficiency, and frailty.

Epidemiology and Public Health

• Heart failure affects $1\%$ to $2\%$ of the global population, totaling over $60,000,000$ cases worldwide.

• In the United States, approximately $2\%$ of adults aged $20$ and older live with the disease.

• The condition accounts for nearly $500,000$ deaths annually in the United States.

• Age is the primary determining factor for prevalence:

  • After the age of $65$, the incidence of heart failure doubles for males every $10$ years.

  • In the same age group, the incidence triples for females every $10$ years.

• Higher incidence rates are observed among specific populations in the U.S., including Black, Hispanic, Asian, and indigenous people, as well as immigrants from developing nations.

Clinical Presentation and Manifestations

• Manifestations vary based on whether the failure is left-sided, right-sided, or biventricular.

• Common Manifestations (Both Sides):

  • Jugular vein distension (JVD).

  • Shortness of breath (dyspnea).

• Left-Sided Heart Failure:

  • Hypotension with tachycardia.

  • Orthopnea and Exertional/Paroxysmal Nocturnal Dyspnea (PND).

  • Peripheral edema in lower extremities.

  • Weight gain and increased abdominal girth.

  • Pulmonary congestion, including rales (bubbling or rattling lung sounds).

  • Productive cough with white or pink blood-tinged sputum.

  • Displaced Point of Maximum Impulse (PMI).

• Right-Sided Heart Failure:

  • Chest discomfort and palpitations.

  • Third heart sound ($S_3$) and murmurs.

  • Ascites (abnormal fluid accumulation in the abdomen).

  • Peripheral edema and generalized swelling.

  • Enlargement of the liver (hepatomegaly) and spleen.

• Key Definitions:

  • Paroxysmal Nocturnal Dyspnea: Shortness of breath that awakens a client from sleep, typically relieved only by sitting up.

  • Rales: Bubbling or rattling sounds heard during lung auscultation.

  • Ascites: Abnormal accumulation of fluid within the abdominal cavity.

Diagnostic Criteria and Severity Classification

• Framingham Diagnostic Criteria: Diagnosis requires meeting two major criteria OR one major and two minor criteria.

  • Major Criteria: Acute pulmonary edema, cardiomegaly, hepatojugular reflux, neck vein distension, PND or orthopnea, pulmonary rales, $S_3$ gallop, radiographic cardiomegaly, central venous pressure greater than $16\,cm$ of water, or a weight loss of $\ge 4.5\,kg$ in $5$ days as a response to treatment.

  • Minor Criteria: Ankle edema, dyspnea on exertion, hepatomegaly, nocturnal cough, pleural effusion, tachycardia (heart rate over $120$ beats per minute), or a decrease in vital capacity by one-third of the maximum recorded value.

• New York Heart Association (NYHA) Functional Classification:

  • Class I: No manifestations; client performs normal activities without limitation.

  • Class II: Slight limitations; client is comfortable at rest but experiences mild manifestations during normal activity.

  • Class III: Moderate limitations; client is comfortable only at rest and experiences symptoms with decreased activity levels.

  • Class IV: Severe limitations; manifestations (chest pain, fatigue, palpitations, fainting) are present even at rest.

Laboratory and Diagnostic Testing

• Blood Profile: Used to assess renal and liver function, check for anemia, and identify iron deficiency.

• Serum B-type Natriuretic Peptide (BNP):

  • Differentiates between cardiac-related and noncardiac dyspnea.

  • Levels correspond with NYHA classes.

  • Pre-discharge levels serve as predictors for readmission and mortality risk.

• Echocardiogram: The primary tool to assess systolic and diastolic function, wall motion abnormalities, and heart valve function.

• Chest X-ray: Evaluates heart size (cardiomegaly) and pulmonary congestion/fluid at the lung bases.

• Other Tests: Electrocardiogram (ECG), cardiac catheterization, and stress tests are used to determine the underlying cause rather than providing a primary diagnosis of heart failure.

Nursing Management and Patient Education

• Environmental Assessment: Home visits allow for evaluating ADLs, meal preparation, and oxygen safety.

• Weight Monitoring: Clients must report a weight gain of more than $2\,lb$ to $3\,lb$ ($0.9\,kg$ to $1.4\,kg$) in a single day or more than $5\,lb$ ($2.3\,kg$) in one week.

• Oxygen Safety Education:

  • Post "No Smoking" signs.

  • Maintain a $6\,ft$ distance from open flames.

  • Ensure safe use of electrical equipment.

• Lifestyle and Dietary Modifications:

  • Sodium restriction: Less than $3\,g/day$ (note: restrictions of $2\,g/day$ are often not more beneficial and harder for clients to sustain).

  • Fluid restriction: Typically $2\,dm^3$ per day for advanced symptoms or hyponatremia.

  • Smoking cessation and limited alcohol/caffeine.

  • Vaccinations: Regular influenza and pneumococcal vaccines are required.

Pharmacological and Surgical Interventions

• Medication Classes:

  • SGLT2 Inhibitors: Shown to reduce hospitalizations and cardiovascular mortality.

  • ACE Inhibitors: Examples include Captopril and Enalapril (Vasotec).

  • Angiotensin II Receptor Blockers (ARBs): Examples include Losartan (Cozaar) and Candesartan (Atacand).

  • ARNIs: Example includes Sacubitril/Valsartan (Entresto).

  • Beta Blockers: Example includes Bisoprolol (Zabeta).

  • Adjuncts: Anticoagulants (for Afib), Statins (for cholesterol or post-MI), and Digoxin.

• Surgical Options:

  • PCI/Cardiac Cath: Reperfuses cardiac muscle during an acute MI.

  • Cardiac Resynchronization Therapy (CRT): Uses a biventricular pacemaker to correct ventricular desynchrony.

  • Implantable Cardioverter Defibrillator (ICD): Inserted for clients with a left ventricular ejection fraction (LVEF) less than $35\%$.

ICD Post-Operative Care

• Activity Restrictions: No lifting objects heavier than $10\,lb$ to $15\,lb$ ($4.5\,kg$ to $6.8\,kg$) for the first $4$ to $6$ weeks.

• Movement Limits: Avoid twisting, pushing, or pulling for $2$ to $3$ weeks. Do not lift the affected arm above shoulder height for $4$ to $6$ weeks.

• Incision Care:

  • Keep dry for $4$ to $5$ days.

  • Pat dry gently after showering; no tub baths, swimming, or hot tubs until fully healed.

  • Monitor for redness, drainage, or increased pain.