HEART FAILURE

• Heart failure (HF) is the inability of the heart to pump sufficient blood to meet the needs of the tissues for oxygen and nutrients.
• Heart failure is defined as the pathophysiologic state in which impaired cardiac function is responsible for inadequate systemic perfusion or unable to maintain an adequate circulation for the metabolic needs of the tissues of the body.
• HF is not an event or disease but rather a constellation of signs and symptoms that represent the final pathway of a heterogeneous group of diseases, the end result of most cardiovascular disease states.

History

• In 1832, James Hope - First described backward failure as the failure that results as the ventricle fails to pump its volume, causing blood accumulation and subsequent increase in ventricular, atrial, and venous pressures. A primary cause of backward failure was mechanical cardiac obstruction.
• In 1913, MacKenzie - The term forward failure was applied to a situation in which the primary pathologic process was decreased cardiac output, which ultimately leads to a decrease in vital organ perfusion, and to water and sodium retention.

Etiology

Heart failure may be caused by one of the following factors, either singly or in combination:

• INTRINSIC PUMP FAILURE - The most common and most important cause of heart failure is weakening of the ventricular muscle due to disease so that the heart fails to act as an efficient pump. That is caused by -
  • Ischaemic heart disease (CAD) – 2/3 of patients with systolic dysfunction
  • Myocarditis
  • Cardiomyopathies
  • Metabolic disorders e.g. beriberi
  • Dysrhythmias e.g. atrial fibrillation and flutter.
• INCREASED WORKLOAD ON THE HEART-Increased mechanical load on the heart results in increased myocardial demand resulting in myocardial failure. Increased load on the heart may be in the form of pressure load or volume load.
  • Increased pressure load may occur in the following states:
    • Systemic and pulmonary arterial hypertension.
    • Valvular disease e.g. mitral stenosis, aortic stenosis, pulmonary stenosis.
    • Chronic lung diseases.
  • Increased volume load occurs when a ventricle is required to eject more than normal volume of the blood resulting in cardiac failure. This is seen in the following conditions:
    • Valvular insufficiency
    • Severe anaemia
    • Thyrotoxicosis
    • Arteriovenous shunts
    • Hypoxia due to lung diseases.
• IMPAIRED FILLING OF CARDIAC CHAMBERS-Decreased CO and cardiac failure may result from extra-cardiac causes or defect in filling of the heart:
  • Cardiac tamponade e.g. haemopericardium, hydropericardium
  • Constrictive pericarditis.
• Other precipitating factors include –
  • Systemic Infections,
  • Anemias,
  • Pulmonary Emboli
  • Administration of Drugs - cardiac depressants or salt-retaining drugs may precipitate HF; examples may include corticosteroids, nondihydropyridine calcium-channel antagonists, and nonsteroidal anti-inflammatory drugs (NSAIDs).
  • Alcohol is a potent myocardial depressant and may be responsible for the development of cardiomyopathy.

Stages of Heart Failure

 

NYHA Functional Classification of Heart Disease

Class I	No limitation of physical activity. Ordinary physical activity does not cause fatigue, dyspnea, palpitations, or anginal pain.
Class II	Slight limitation of physical activity. No symptoms at rest. Ordinary physical activity results in fatigue, dyspnea, palpitations, or anginal pain.
Class III	Marked limitation of physical activity but usually comfortable at rest. Less than ordinary physical activity causes fatigue, dyspnea, palpitations, or anginal pain.
Class IV	Inability to carry on any physical activity without discomfort. Symptoms of cardiac insufficiency or of angina may be present even at rest. If any physical activity is undertaken, discomfort is increased.

 

ACCF/AHA Stages of Heart Failure

Stage A	Patients at high risk for HF (e.g., patients with hypertension, diabetes, metabolic syndrome) but without structural heart disease or symptoms of HF.
Stage B	Patients with structural heart disease (e.g., patients with history of MI, valve disease) but who have never shown signs or symptoms of HF.
Stage C	Patients with prior or current symptoms of HF associated with known, underlying structural heart disease.
Stage D	Patients with refractory HF (e.g., patients with severe symptoms at rest despite maximal medical therapy) who require specialized interventions.

Types of Heart Failure

• Heart failure may be acute or chronic, right-sided or left-sided, and forward or backward failure.

ACUTE AND CHRONIC HEART FAILURE

• Depending upon whether the heart failure develops rapidly or slowly, it may be acute or chronic.
• Acute heart failure - Sudden and rapid development of heart failure. It occurs in the following conditions:
  • Larger myocardial infarction
  • Valve rupture
  • Cardiac tamponade
  • Massive pulmonary embolism
  • Acute viral myocarditis
  • Acute bacterial toxaemia.
• In acute heart failure, there is sudden reduction in cardiac output resulting in systemic hypotension but oedema does not occur. Instead, a state of cardiogenic shock and cerebral hypoxia develops.
• Chronic heart failure - More often, heart failure develops slowly. It observed in the following states:
  • Myocardial ischaemia from atherosclerotic coronary artery disease
  • Multi-valvular heart disease
  • Systemic arterial hypertension
  • Chronic lung diseases resulting in hypoxia and pulmonary arterial hypertension
  • Progression of acute into chronic failure.
• In chronic heart failure, compensatory mechanisms like tachycardia, cardiac dilatation and cardiac hypertrophy try to make adjustments so as to maintain adequate cardiac output. This often results in well-maintained arterial pressure and there is accumulation of oedema.
• The term congestive heart failure (CHF) is used for the chronic form of heart failure in which the patient has evidence of congestion of peripheral circulation and of lungs.

LEFT-SIDED AND RIGHT-SIDED HEART FAILURE.

• Though heart as an organ eventually fails as a whole, but functionally, the left and right heart act as independent units. So, from clinical point of view, it is helpful to consider failure of the left and right heart separately.
• Left-sided heart failure - It is initiated by stress to the left heart. The major causes are -
  • Systemic hypertension
  • Mitral or aortic valve disease (stenosis)
  • Ischaemic heart disease
  • Myocardial diseases e.g. cardiomyopathies, myocarditis.
  • Restrictive pericarditis.
• Right-sided heart failure - Right-sided heart failure occurs more often as a consequence of left-sided heart failure but in some conditions affect the right ventricle primarily, producing right-sided heart failure. These are as follows:
  • As a consequence of left ventricular failure.
  • Cor pulmonale in which right heart failure occurs due to intrinsic lung diseases.
  • Pulmonary or tricuspid valvular disease.
  • Pulmonary hypertension secondary to pulmonary thromboembolism.
  • Myocardial disease affecting right heart.
  • Congenital heart disease with left-to-right shunt.

BACKWARD AND FORWARD HEART FAILURE.

• The mechanism of clinical manifestations resulting from heart failure can be explained on the basis of mutually interdependent backward and forward failure.
• Backward heart failure – in the backward heart failure the ventricles fails to eject blood normally, resulting in rise of end-diastolic volume in the ventricle and increase in volume and pressure in the atrium which is transmitted backward producing elevated pressure in the veins.
• Forward heart failure – inn the forward heart failure, Due to the failure of to the heart pump blood causing diminished flow of blood to the tissues, especially diminished renal perfusion and activation of renin-angiotensin-aldosterone system.

SYSTOLIC AND DIASTOLIC DYSFUNCTION

1. Systolic dysfunction causes inadequate pumping of blood from the ventricles and decreases cardiac output. Any process that alters myocardial contractility can produce systolic dysfunction. Most common are ischemic heart disease and hypertension.
2. Diastolic dysfunction (stiff heart syndrome) occurs when the ventricles does not fill adequately during diastole. Inadequate filling decreases the amount of blood available in the ventricle for cardiac output. Hypertension and CAD are the primary causes of diastolic dysfunction.

Pathophysiology

LEFT-SIDED HEART FAILURE

RIGHT-SIDED HEART FAILURE

Clinical Manifestation

LEFT-SIDED HEART FAILURE

RIGHT-SIDED HEART FAILURE

Persistent cough Pink, frothy sputum Adventitious breaths sounds - bi-basilar crackles Tachycardia Tachypnea Noisy, labored breathing Rales, wheezing ("cardiac asthma") Dry hacking cough Cyanosis (late) Dyspnea on exertion Paroxysmal nocturnal dyspnea Orthopnea Fatigue, generalized weakness Increased BP (from fluid volume excess) or decreased BP (from pump failure) Oliguria Altered digestion Dizziness, lightheadedness, confusion, restlessness, anxiety

Tachycardia Jugular venous distension Dependent edema (Pedal, pre-tibial, sacral) Swelling of fingers and hands Hepatomegaly, tenderness in right upper quadrant Respiratory distress Splenomegaly Anorexia, nausea Weight gain Nocturnal diuresis Anasarca (generalized edema) Fluid accumulation in body cavities Ascites Increased BP (from fluid volume excess) or decreased BP (from pump failure) Pericardial effusion Pleural effusion Increased abdominal girth Pitting edema

Diagnostic test

The diagnosis of CHF rests primarily on presenting manifestations and pertinent data from client's health history. Diagnostic studies assist in determining underlying cause and degree of heart failure. The various diagnostic tests are -

• Echocardiography-two-dimensional with Doppler flow studies—may show ventricular hypertrophy, dilation of chambers, and abnormal wall motion. Makes definitive diagnosis of type of heart failure (systolic or diastolic).
• ECG (resting and exercise)—may show ventricular hypertrophy and ischemia.
• Chest X-ray may show cardiomegaly, pleural effusion, and vascular congestion.
• Cardiac catheterization—to rule out CAD.
  • Right-sided heart catheterization—to measure pulmonary pressure and left ventricular function.
• ABG studies may show hypoxemia due to pulmonary vascular congestion.
• Blood studies: CBC, electrolytes, Ca, Mg, renal function, glycohemoglobin, lipid profile, thyroid function, and liver function studies may be altered because of hepatic congestion.
• Human B-type natriuretic peptide (BNP, triage BNP, Nterminal prohormone brain NP, or proBNP).
  • As volume and pressure in the cardiac chambers rise, cardiac cells produce and release more BNP. This test aids in the diagnosis of heart failure.
  • A level greater than 100/mL is diagnostic for heart failure. In addition, the higher the BNP, the more severe the heart failure.
  • BNP is used in emergency departments to quickly diagnose and start treatment.

LEFT SIDED HEART FAILURE

• Chest X-ray (CXR): reveals cardiomegaly
• Pulmonary Arterial Pressure (PAP): measures pressure in right ventricle or cardiac status: increased
• Pulmonary Capillary Wedge Pressure (PCWP): measures end systolic and dyastolic pressure: increased
• Central Venous Pressure (CVP): indicates fluid or hydration status
  • Increase CVP: decreased flow rate of IV
  • Decrease CVP: increased flow rate of IV
• Swan-Ganz catheterization: cardiac catheterization
• Echocardiography: shows increased sized of cardiac chamber (cardiomyopathy): dependent on extent of heart failure
• ABG: reveals PO₂ is decreased (hypoxemia), PCO₂ is increased (respiratory acidosis)

RIGHT SIDED HEART FAILURE

1. Chest X-ray (CXR): reveals cardiomegaly
2. Central Venous Pressure (CVP): measure fluid status: elevated
   1. Measure pressure in right atrium: 4-10 cm of water
   2. If CVP is less than 4 cm of water: Hypovolemic shock: increase IV flow rate
   3. If CVP is more than 10 cm of water: Hypervolemic shock: Administer loop diuretics as ordered
   4. Nursing Intervention:
      1. When reading CVP patient should be flat on bed
      2. Upon insertion place client in trendelendberg position: to promote ventricular filling and prevent pulmonary embolism
3. Echocardiography: reveals increased size of cardiac chambers (cardiomyopathy)
4. Liver enzymes: SGPT & SGOT: is increased
5. ABG: decreased pO2

Management

GOALS OF MANAGEMENT

• The main goal in the management of CHF is to improve ventricular pump performance and reduce myocardial workload.

ACCORDING TO ACC/AHA STAGE

• Stage A—focuses on eliminating risk factors by initiating therapeutic lifestyle changes, such as smoking cessation, increasing physical activity, and decreasing alcohol consumption. This stage also focuses on controlling chronic diseases, such as hypertension, high cholesterol, and diabetes. Beta-adrenergic blockers, ACE inhibitors, and diuretics are useful in treating this stage.
• Stage B—treatment similar to Stage A, with emphasis on use of ACE inhibitors and beta-adrenergic blockers.
• Stage C—same as A and B, but with closer surveillance and follow-up.
  • Digoxin is typically added to the treatment plan in this stage.
  • Use of diuretic, hydralazine, nitrate, aldosterone antagonist as indicated.
  • Drug classes to be avoided due to worsening of heart failure symptoms include anti-arrhythmic agents, calcium channel blockers, and NSAIDs.
  • Patients post-MI who have New York State Heart Association class II or III symptoms are recommended for implantable cardioverter defibrillator (ICD) placement.
• Stage D—may need mechanical circulatory support, continuous inotropic therapy, cardiac transplantation, or palliative care.
  • Treatment aimed at decreasing excess body fluid.
  • May not tolerate other classes of drugs used in previous stages.

DRUG THERAPY

• ACE inhibitors (decrease left ventricle dilation and remodeling)—inhibit the adverse effects of angiotensin II (potent vasoconstriction/sodium retention). Decreases left ventricular afterload with a subsequent decrease in heart rate associated with heart failure, thereby reducing the workload of the heart and increasing CO. May decrease remodeling of the ventricle.
  • Captopril and enalapril are commonly used.
• Angiotensin II-receptor blockers—similar to ACE inhibitors. Used in patients who cannot tolerate ACE inhibitors due to cough or angioedema.
• Beta-adrenergic blockers—decrease myocardial workload and protect against fatal dysrhythmias by blocking norepinephrine effects of the sympathetic nervous system.
  • Metoprolol or metoprolol CR or XL are commonly used.
  • Carvedilol is a nonselective beta- and alpha-adrenergic blocker. Patients may actually experience increase in general malaise for a 2- to 3-week period while they adjust to the medication.
• Diuretics (preload reduction)
  • Eliminate excess body water and decrease ventricular pressures.
  • A low-sodium diet and fluid restriction complement this therapy.
  • Some diuretics may have slight venodilator properties.
• Positive inotropic agents—increase the heart's ability to pump more effectively by improving the contractile force of the muscle.
  • Digoxin may only be effective in severe cases of failure.
  • Dopamine improves renal blood flow in low dose range.
  • Dobutamine - Increases contractility
  • Milrinone and amrinone are potent vasodilators and increase contractility.
• Nitroglycerin
  • Systolic BP should be > 90 - 100 mm Hg
  • Nitrate therapy before IV is started
  • Reduces preload/afterload
  • Improves coronary artery perfusion
  • Caution in RVF
  • NTG, Lasix may worsen hypotension
  • Use inotropes if fluid does not improve BP following NTG administration
• Vasodilator therapy—decreases the workload of the heart by dilating peripheral vessels. By relaxing capacitance vessels (veins and venules), vasodilators reduce ventricular filling pressures (preload) and volumes. By relaxing resistance vessels (arterioles), vasodilators can reduce impedance to left ventricular ejection and improve stroke volume.
  • Nitrates (preload reducers), such as nitroglycerin, isosorbide, nitroglycerin ointment—predominantly dilate systemic veins
  • Hydralazine —predominantly affects arterioles; reduces arteriolar tone
  • Prazosin—balanced effects on both arterial and venous circulation
  • Sodium nitroprusside (afterload reducers)—predominantly affects arterioles
  • Morphine—enhances peripheral dilation, decreases venous return, and decreases pain and anxiety, thus decreasing workload of the heart
• Aldosterone antagonists—decrease sodium retention, sympathetic nervous system activation, and cardiac remodeling.
  • Spironolactone is most commonly used.
  • May cause hyperkalemia, especially in those with impaired renal function, in those taking high doses of ACE inhibitors, or in those who use potassium supplements.
• Human BNP (decreases pulmonary artery pressure)—used in patients with decompensated heart failure. It produces smooth muscle cell relaxation and diuresis and a reduction in afterload and dyspnea.
• Amiodarone—to treat arrhythmias.
• Calcium Channel Blockers
  • First-generation - verapamil, nifedipine, and diltiazem are contraindicated in systolic HF, may be used in patients with diastolic HF
  • Amlodipine and felodipine, - dihydropyridine calcium channel blockers, cause vasodilation, reducing systemic vascular resistance, may use to improve symptoms, especially in nonischemic cardiomyopathy.

NUTRITIONAL THERAPY

• Restricted sodium –
  • A low-sodium (2 to 3 g/day) diet
  • To reduces fluid retention and the symptoms of peripheral and pulmonary congestion. To decrease the amount of circulating blood volume
• Restricted fluids
  • Avoidance of drinking excessive amounts of fluid

ADDITIONAL THERAPY

• Positioning- the client is placed in a high fowler's position to reduce pulmonary venous congestion and ease dyspnea. The legs are maintained in a dependent position.
• Oxygen Administration- is provided in high concentration by mask or cannula.
• Consider intubation if:
  • O₂ saturation cannot be kept >90% on 100% O₂
  • PaO₂ cannot be kept >60 or on 100 % O₂
  • Patient displays signs of worsening cerebral hypoxia
  • PaCO₂ progressively increases
  • Patient becoming exhausted
• Monitor ECG
  • Hypoxia, increased heart wall tension leads to dysrhythmias
  • Limit Fluids
  • If RVF only, fluid challenges to increase preload

FIRST LINE DRUG THERAPY

• Nitroglycerin
• Furosemide (Lasix)
• Morphine Sulfate
• Dobutamine
• Bronchodilators (Beta Agonists)
• if the BP is too low (BP < 70 mm Hg) - norepinephrine, 0.5 - 30 mcg/min IV infusion
• If the BP > 70 but < 100 mm Hg - dopamine, 5 - 15 mcg/kg/min IV infusion, After BP improves, treat pulmonary edema

LONG TERM MANAGEMENT

• Long Term Management usually includes -
• Fluid minimization
• Diuretics (+ Potassium if non-potassium sparing)
• Diet restrictions
• Increase contractility - Digitalis
• Blood pressure control - ACE Inhibitors
• Coronary artery perfusion - Nitroglycerin

Nursing management

• Goal: Increase cardiac contractility thereby increasing cardiac output of 3-6 L / min

NURSING INTERVENTION

• Monitor respiratory status & provide adequate ventilation (when HF progress to pulmonary edema)

1. Administer O₂ therapy: high inflow 3-4 L / min delivered via nasal cannula
2. Maintain client in semi or high fowlers position: maximize oxygenation by promoting lung expansion
3. Monitor ABG
4. Assess for breath sounds: noting any changes

• Provide physical & emotional rest

1. Constantly assess level of anxiety
2. Maintain bed rest with limited activity
3. Maintain quiet & relaxed environment
4. Organized nursing care around rest periods

• Increase cardiac output

1. Administer digitalis as ordered & monitor effects
   1. Cardiac glycosides: Digoxin (Lanoxin)
   2. Action: Increase force of cardiac contraction
   3. Contraindication: If heart rate is decreased do not give
2. Monitor ECG & hemodynamic monitoring
3. Administer vasodilators as ordered
   1. Vasodilators: Nitroglycerine (NTG)
4. Monitor V/S

• Reduce / eliminate edema or managing fluid volume

1. Administer diuretics as ordered
   1. Loop Diuretics: Lasix (Furosemide)
2. Daily weight
3. Maintain accurate I&O
4. Assess for peripheral edema
5. Measure abdominal girth daily
6. Monitor electrolyte levels
7. Monitor CVP & Swan-Ganz reading
8. Provide Na restricted diet as ordered
9. Provide meticulous skin care

• If acute pulmonary edema occurs: For Left Sided Heart Failure only

1. Administer Narcotic Analgesic as ordered
   1. Narcotic analgesic: Morphine SO4
   2. Action: to allay anxiety & reduce preload & afterload
2. Administer Bronchodilator as ordered
   1. Bronchodilators: Aminophylline IV
   2. Action: relieve bronchospasm, increase urinary output & increase cardiac output
3. Administer Anti-arrythmic as ordered
   1. Anti-arrythmic: Lidocaine (Xylocane)

• Provide client teaching & discharge planning concerning:

1. Need to self-monitor daily - sign and symptoms of Heart Failure (pedal edema, weight gain, of 1-2 kg in a 2 day period, dyspnea, loss of appetite, cough)
2. Medication regimen including name, purpose, dosage, frequency & side effects (digitalis, diuretics)
3. Prescribe diet plan (low Na, cholesterol, caffeine: small frequent meals)
4. Need to avoid fatigue & plan for rest periods
5. Prevent complications
   1. Arrythmia
   2. Shock
   3. Right ventricular hypertrophy
   4. MI
   5. Thrombophlebitis
6. Importance of follow-up care