Heart Failure (HF): Symptoms, Causes, Types, Pathophysiology and Treatment

Heart failure is the inability of the heart to pump sufficient blood to meet the metabolic needs of the body. It is usually due to inadequate cardiac output (CO) resulting in poor organ perfusion and vascular congestion in the pulmonary or systemic circulation. HF is a clinical syndrome characterized by signs and symptoms of fluid overload or of inadequate tissue perfusion. These signs and symptoms result when the heart is unable to generate a CO sufficient to meet the body’s demands. Some cases of HF are reversible, depending on the cause. Most often, HF is a life-long diagnosis that is managed with lifestyle changes and medications to prevent acute congestive episodes. This article explores the causes, risk factors, symptoms, diagnosis, and comprehensive management strategies for heart failure, emphasizing the importance of lifestyle changes and medical interventions.

What is Heart Failure (HF)

Heart failure (HF) or congestive heart failure (CHF) or ventricular failure is the inability of the heart to pump sufficient blood to meet the metabolic needs of the body.

Causes of Heart Failure

Acute Causes (these causes result in a sudden onset of the condition)

• Angina pectoris
• Acute myocardial infarction
• Arrhythmias
• Pulmonary embolism
• Hypertensive crisis
• Thyrotoxicosis
• Ventricular septal defect
• Myocarditis

Chronic Causes (these causes result from a long-standing heart disease or condition)

• Chronic artery diseases
• Rheumatic heart disease
• Hypertensive heart disease
• Cor pulmonale
• Bacterial endocarditis
• Cardiomyopathy
• Anemia
• Valvular stenosis

Risk factors

• Aging
• Stress
• Diabetes mellitus
• Obesity
• Cigarette smoking
• High serum cholesterol

Types of Heart Failure

There are two types of heart failure. They are:

1. Left ventricular heart failure / left sided heart failure
2. Right ventricular heart failure / right sided heart failure

Left sided failure (Left ventricular failure)

This is the initial and most common heart failure. It occurs when the left ventricle is unable to produce a sufficient cardiac output to prevent pulmonary congestion. Pulmonary congestion occurs when the left ventricle cannot pump blood out of the ventricle to the body.When myocardial conductivity of the left ventricle becomes impaired, there is an increased pressure initially in the left ventricle creating congestion in the left ventricle. The congestion in the left ventricle subsequently persists and causes a back flow of blood through the mitral valve to the left atrium, pulmonary veins and the lungs.The increased pulmonary pressure causes fluid accumulation from the pulmonary capillary beds into the alveolar manifesting as pulmonary congestion and edema. LVF can also be described as backward failure and forward failure.In backward failure, the ventricle fails to eject its content, resulting in pulmonary edema on the left side of the heart.In forward failure, an inadequate cardiac output leads to decreased organ perfusion and decreased oxygenation.

Right sided heart failure (Right ventricular failure)

This is failure of the right ventricle to pump adequate blood into pulmonary circulation. When contraction of the right ventricle becomes inadequate, the ventricles become congested with blood. When this occurs, the right ventricle is unable to maintain an adequate cardiac output and systemic congestion occurs. It causes backward flow of blood through the tricuspid valve to the right atrium, vena cava, and to venous or systemic circulation. This subsequently leads to congestion of fluid in all part of the body.Hence, when the right ventricle fails, congestion of the viscera and the peripheral tissues predominate. This occurs because the right side of the heart cannot eject blood and cannot accommodate all the blood that normally returns to it from the venous circulation.The increase in venous pressure leads to hepatomegaly, splenomegaly, peripheral edema, and jugular vein distention. RVF can also be described as backward failure and forward failure.In backward failure, the ventricle fails to eject its content, resulting in systemic congestion.In forward failure, an inadequate cardiac output leads to decreased organ perfusion and decreased oxygenation.

Pathophysiology of Heart Failure

In heart failure, the heart is unable to generate enough cardiac output to pump sufficient blood to meet the body’s metabolic demands. When myocardial contraction of the left ventricle or right ventricle becomes impaired, it leads to an increased pressure and congestion in the left or right ventricle.The congestion in the left ventricle or right ventricle results in the back flow of blood, causing pulmonary congestion or systemic congestion. Low cardiac output stimulates the sympathetic nervous system to release epinephrine and norepinephrine. These cause an increase in heart rate, myocardial contractility and peripheral vasoconstriction. This mechanism initially improves the cardiac output but eventually leads to an increased myocardial demand for oxygen and worsens the burden of the heart.The ventricular congestion and pressure also cause the left ventricle or right ventricle to dilate and then hypertrophy in order to increase the cardiac output. This compensatory reaction however becomes unsustainable, and the cardiac output begins to decrease overtime. The decreased cardiac output causes a decrease blood flow to the kidney.In response, the kidneys release renin which acts on angiotensinogen and converts it to angiotensin I. Angiotensin converting enzyme converts angiotensin I to angiotensin II. Angiotensin II causes the adrenal cortex to release aldosterone which also causes the retention of sodium and increased peripheral vasoconstriction to raise the blood pressure. The low cardiac output also causes decreased cerebral perfusion.This causes the posterior pituitary gland to release ADH (antidiuretic hormone) which leads to water retention and increased blood volume. This is however detrimental to the person who is already having an overloaded volume.

Signs & Symptoms of left sided heart failure

• Cough. The cough associated with left ventricular failure is initially dry and nonproductive. The cough may become moist. Large quantities of frothy sputum, which is sometimes pink (blood tinged), may be produced, usually indicating severe pulmonary congestion (pulmonary edema)
• Pulmonary crackles due to the pulmonary congestion
• Dyspnea or shortness of breath. Dyspnea also can occur at rest. Because the impaired left ventricle cannot eject the increased circulating blood volume, the pressure in the pulmonary circulation increases, causing further shifting of fluid into the alveoli. The fluid filled alveoli cannot exchange oxygen and carbon dioxide.
• Orthopnoea (difficulty in breathing when lying flat). Patients with orthopnea usually prefer not to lie flat. They may need pillows to prop themselves up in bed, or they may sit in a chair and even sleep sitting up.
• Some patients have sudden attacks of orthopnea at night, a condition known as paroxysmal nocturnal dyspnea (PND).
• Blood flow to the kidneys decreases, causing decreased perfusion and reduced urine output (oliguria).
• When the patient is sleeping, the cardiac workload is decreased, improving renal perfusion, which then leads to frequent urination at night (nocturia).
• Decreased CO causes other symptoms. Decreased gastrointestinal perfusion causes altered digestion, nausea and vomiting
• Decreased brain perfusion causes dizziness, lightheadedness, confusion, restlessness, and anxiety due to decreased oxygenation and blood flow.
• Cyanosis, pallor. Stimulation of the sympathetic system also causes the peripheral blood vessels to constrict, so the skin appears pale. Pale or cyanotic, cool, clammy skin is a result of poor perfusion.
• Tachycardia. The patient’s vital signs may demonstrate tachypnoea or tachycardia, which occur in an attempt to compensate for the hypoxia and decreased CO.
• Palpitation due to the pulmonary congestion
• Fatigue due to the decreased organ perfusion
• Insomnia due to cough, dyspnea, and pulmonary congestion

Signs & symptoms of right sided heart failure

• Edema of the lower extremities (dependent edema). Edema usually affects the feet and ankles, worsening when the patient stands or dangles the legs. The swelling decreases when the patient elevates the legs. The edema can gradually progress up the legs and thighs and eventually into the external genitalia and lower trunk.
• Hepatomegaly (enlargement of the liver) results from venous engorgement of the liver. The increased pressure may interfere with the liver’s ability to perform
• Tenderness in the right upper quadrant of the abdomen results from venous engorgement of the liver. The increased pressure may interfere with the liver’s ability to perform
• Hepatomegaly may also increase pressure on the diaphragm, causing respiratory distress.
• Distended jugular veins due to the systemic congestion
• Ascites (accumulation of fluid in the peritoneal cavity) due to the systemic congestion
• Anasarca (generalized edema) due to the systemic congestion
• Weakness and fatigue. The weakness or fatigue that accompanies right sided HF results from reduced CO, impaired circulation, and inadequate removal of catabolic waste products from the tissues.
• Weight gain due to retention of fluid
• This collection of fluid in the abdominal cavity may increase pressure on the stomach and intestines and cause gastrointestinal distress. Anorexia (loss of appetite), vomiting and nausea or abdominal pain results from the venous engorgement and venous stasis within the abdominal organs.

Diagnostic Investigations & Test

• Chest X-ray to show pulmonary congestion, cardiomegaly, and pulmonary edema
• Echocardiography for cardiomegaly, ventricular function, valvular structure and function.
• Arterial blood gas analysis for oxygen levels
• Electrocardiography for ventricular hypertrophy and ventricular dilatation
• Blood urea nitrogen (BUN) for urea, nitrogen and other waste products in the blood
• Cardiac catheterization is done to determine the cause. This is a procedure in which a thin, flexible tube (catheter) is guided through a blood vessel to the heart to diagnose or treat certain heart conditions such as clogged arteries or irregular heartbeats.
• Angiography. Angiography is a type of X-ray used to check blood vessels. Blood vessels do not show clearly on a normal X-ray, so a special dye needs to be injected into your blood first. This highlights your blood vessels, allowing your doctor to see any problems.
• History taking and physical examination.
• CT scan of the chest for pulmonary congestion, cardiomegaly, and pulmonary edema

Medical Management of Heart Failure

• Oxygen therapy for pulmonary congestion and resulting hypoxia
• ACE inhibitors such as captopril, enalapril etc. for vasodilation. Vasodilation reduces resistance to left ventricular ejection of blood, diminishing the heart’s workload and improving ventricular emptying.
• Anti hypertensives such as hydralazine and nifedipine to improve cardiac output
• Diuretics are medications used to increase the rate of urine production and the removal of excess extracellular fluid from the body.
• Analgesics such as morphine and paracetamol for pain. NSAIDs such as ibuprofen should be avoided. They can increase systemic vascular resistance and decrease renal perfusion, especially in the elderly.
• Digitalis/Cardiotonics. The most commonly prescribed form of digitalis or cardiotonics for patients with HF is digoxin. Digoxin slows the heart rate. The medication also enhances diuresis, which removes fluid and relieves edema. Before administering digoxin, it is standard nursing practice to assess apical heart rate.
• Anticoagulants may be prescribed, especially if the patient has a history of an embolic event or atrial fibrillation or mural thrombus is present.
• Other medications such as anti-anginal medications may be given to treat the underlying cause of HF.

Nursing Management of Heart Failure

The following are the measures to put in place in the care of patients with heart failure

• Complete bed rest
• Patient is nursed in a well-supported upright or semi-fowlers position supported with pillows
• Reassure patient and family
• Administer prescribed oxygen PRN
• Nurse patient in a well-ventilated room
• Provide calm and quite environment
• Encourage activities within prescribed restriction
• Monitor for intolerance to activity and assist patient with activities of daily living.
• Monitor vital signs and record accurately
• Monitor fluid restrictions
• Weigh patient daily and record
• Measure abdominal girth
• Monitor intake and output chart
• Assess for changes in mental state
• Maintain personal hygiene (frequent oral care)
• Engage patient in moderate exercise one that they can perform in bed such as lifting up the leg
• Serve patient with diet containing low amounts of salt and which is easily digestible
• Educate patient on the condition, medications prescribed, activity restrictions, fluid restrictions, and lifestyle changes. Written material should be provided for the patient to take home and use as a reference.