Heart failure is a serious condition in which the heart cannot fill with blood or pump blood effectively enough to meet the body’s needs. It does not always mean the heart has stopped working. It means the heart is weaker, stiffer or overloaded, so blood flow becomes less efficient. This leads to reduced cardiac output, fluid buildup and symptoms that affect breathing, energy, swelling and daily activity.
Heart failure can affect the left side, right side or both sides of the heart. Left-sided heart failure often causes blood to back up into the lungs, leading to shortness of breath, crackles, fatigue and sometimes pink frothy sputum. Right-sided heart failure causes blood to back up into the body, leading to peripheral edema, ascites, jugular venous distention and liver enlargement.
Common causes include cardiomyopathy, coronary artery disease, myocardial infarction, hypertension, endocarditis, congenital heart disease, arrhythmias and alcohol or drug use. Diagnosis often includes BNP blood testing, chest X-ray, stress testing, cardiac catheterization and echocardiography. Ejection fraction helps show how well the left ventricle pumps blood.
What Is Heart Failure?
Heart failure is a clinical syndrome where the heart cannot pump enough blood or fill properly during relaxation. This reduces oxygen delivery to tissues and causes fluid congestion in the lungs, legs, abdomen or other body areas.
The American Heart Association describes heart failure as a condition where the heart cannot pump enough blood to meet the body’s needs. It may develop after damage from conditions such as coronary artery disease, high blood pressure or cardiomyopathy.
Heart failure may be:
- Acute, when symptoms develop quickly
- Chronic, when symptoms develop slowly over time
- Compensated, when symptoms are controlled
- Decompensated, when symptoms worsen and need urgent care
Why Heart Failure Lowers Cardiac Output
Cardiac output is the amount of blood pumped by the heart each minute.
Cardiac output depends on:
| Factor | Meaning |
|---|---|
| Heart rate | How fast the heart beats |
| Stroke volume | How much blood leaves the ventricle per beat |
| Preload | Blood volume returning to the heart |
| Afterload | Pressure the heart pumps against |
| Contractility | Strength of heart muscle contraction |
In heart failure, one or more of these factors becomes abnormal. The heart may not squeeze strongly, may not relax well or may pump against high pressure. As a result, blood backs up and organs receive less oxygen-rich blood.
Causes of Heart Failure
Heart failure can happen after anything that damages, weakens or overloads the heart.
Common causes include:
- Cardiomyopathy
- Coronary artery disease
- Myocardial infarction
- Hypertension
- Endocarditis
- Congenital heart disease
- Arrhythmias
- Alcohol or drug use
The 2022 AHA/ACC/HFSA guideline explains that heart failure care includes identifying causes, staging disease, assessing ejection fraction and using evidence-based treatment to reduce symptoms and hospitalizations.
Coronary Artery Disease and Myocardial Infarction
Coronary artery disease reduces blood flow to the heart muscle. A myocardial infarction, or heart attack, can permanently damage heart muscle cells.
When damaged muscle cannot contract well, the heart becomes weaker. This may lead to heart failure with reduced ejection fraction.
Hypertension
Long-term high blood pressure forces the heart to pump against high resistance. Over time, the left ventricle may become thick, stiff or weak.
Hypertension is one of the most common long-term contributors to heart failure.
Cardiomyopathy
Cardiomyopathy is disease of the heart muscle. The muscle may become dilated, thick, stiff or weak.
This directly affects the heart’s ability to fill or pump.
Endocarditis
Endocarditis can damage heart valves. Damaged valves may leak or narrow, forcing the heart to work harder.
Severe valve damage can lead to heart failure.
Arrhythmias
Fast, slow or irregular rhythms can reduce filling time and pumping efficiency. Atrial fibrillation, ventricular tachycardia and severe bradycardia can all worsen heart failure.
Types of Heart Failure
Heart failure is often classified by location and ejection fraction.
Main classifications include:
- Left-sided heart failure
- Right-sided heart failure
- Heart failure with reduced ejection fraction
- Heart failure with preserved ejection fraction
- Acute decompensated heart failure
Left-Sided Heart Failure
Left-sided heart failure occurs when the left ventricle cannot pump blood effectively to the body. Blood backs up into the lungs.
A simple memory tip is:
L for left, L for lungs.
Symptoms of Left-Sided Heart Failure
Common symptoms include:
- Dyspnea, or shortness of breath
- Shortness of breath on exertion
- Orthopnea
- Paroxysmal nocturnal dyspnea
- Crackles in the lungs
- Fatigue
- Cough
- Pink frothy sputum in severe pulmonary edema
- Low oxygen saturation
- Restlessness or anxiety
Why Crackles Happen
When the left side of the heart fails, pressure builds in the pulmonary veins. Fluid can move into lung tissue and air spaces. This causes crackles, difficulty breathing and reduced gas exchange.
Severe fluid buildup in the lungs is called pulmonary edema.
Right-Sided Heart Failure
Right-sided heart failure occurs when the right ventricle cannot pump blood effectively to the lungs. Blood backs up into the body.
A simple memory tip is:
R for right, R for rest of body.
Symptoms of Right-Sided Heart Failure
Common symptoms include:
- Peripheral edema
- Ascites
- Jugular venous distention
- Hepatomegaly
- Weight gain
- Abdominal fullness
- Nausea
- Poor appetite
- Swollen ankles or legs
Why Edema Happens
When the right side fails, venous pressure rises. Fluid leaks from blood vessels into tissues.
This causes swelling in the legs, ankles and abdomen.
Left-Sided vs Right-Sided Heart Failure
| Feature | Left-Sided Heart Failure | Right-Sided Heart Failure |
| Main backup area | Lungs | Body |
| Key memory | L for lungs | R for rest of body |
| Common symptoms | Dyspnea, crackles, fatigue | Edema, ascites, JVD |
| Severe sign | Pink frothy sputum | Hepatomegaly |
| Main problem | Poor systemic pumping | Poor pulmonary pumping |
| Common result | Pulmonary congestion | Systemic congestion |
Ejection Fraction in Heart Failure
Ejection fraction, or EF, is the percentage of blood pumped out of the left ventricle with each beat.
An echocardiogram is commonly used to measure EF.
| EF Category | Meaning |
| 55% to 70% | Commonly considered normal |
| 41% to 49% | Mildly reduced range |
| 40% or less | Reduced ejection fraction |
| Above normal | May occur in some stiff-heart states |
The AHA/ACC/HFSA guideline defines major heart failure categories using left ventricular ejection fraction, including HFrEF at 40% or less, HFmrEF at 41% to 49% and HFpEF at 50% or higher.
Heart Failure With Reduced vs Preserved Ejection Fraction
| Type | EF Pattern | Main Problem |
| HFrEF | EF 40% or less | Weak pumping |
| HFmrEF | EF 41% to 49% | Mildly reduced pumping |
| HFpEF | EF 50% or higher | Stiff filling problem |
| HFimpEF | EF improved after treatment | Prior reduced EF improved |
HFrEF
Heart failure with reduced ejection fraction means the left ventricle cannot squeeze strongly enough. This is often called systolic heart failure.
HFpEF
Heart failure with preserved ejection fraction means the ventricle may squeeze normally but cannot relax and fill well. This is often called diastolic heart failure.
Symptoms of Heart Failure
Heart failure symptoms may appear slowly or suddenly.
Common symptoms include:
- Shortness of breath
- Fatigue
- Reduced exercise tolerance
- Swelling in feet, ankles or legs
- Weight gain from fluid
- Cough
- Wheezing
- Chest discomfort
- Palpitations
- Dizziness
- Confusion in older adults
- Poor appetite
- Trouble sleeping flat
Symptoms often worsen with excess sodium, missed medicines, infection, arrhythmias, kidney problems or uncontrolled blood pressure.
Warning Signs of Worsening Heart Failure
Seek urgent care if there is:
- Severe shortness of breath at rest
- Pink frothy sputum
- Chest pain
- Fainting
- New confusion
- Fast or irregular heartbeat with symptoms
- Blue lips
- Sudden weight gain
- Severe leg swelling
- Very low blood pressure
- Oxygen level dropping
Sudden breathing distress with crackles may signal acute pulmonary edema.
Diagnosis of Heart Failure
Heart failure diagnosis uses symptoms, physical exam, labs and imaging.
Common tests include:
- BNP or NT-proBNP blood test
- Chest X-ray
- Echocardiogram
- ECG
- Stress test
- Cardiac catheterization
- Blood tests
- Kidney function tests
- Electrolytes
- Thyroid testing in selected cases
BNP Blood Test
BNP, or brain natriuretic peptide, is released when heart ventricles stretch from pressure or fluid overload.
BNP can support heart failure diagnosis, especially when a patient has shortness of breath.
| BNP Level | General Meaning |
| Less than 100 pg/mL | Heart failure less likely |
| 100 to 300 pg/mL | Possible heart failure |
| 300 to 600 pg/mL | Mild heart failure range |
| 600 to 900 pg/mL | Moderate heart failure range |
| 900+ pg/mL | Severe heart failure range |
BNP values must be interpreted with age, kidney function, obesity, symptoms and clinical findings. BNP can rise in heart failure, kidney disease and other cardiac stress states.
Chest X-Ray
A chest X-ray may show:
- Cardiomegaly
- Pulmonary congestion
- Pleural effusion
- Interstitial edema
- Alveolar infiltrates
Chest X-ray helps assess fluid overload, but it does not replace echocardiography.
Echocardiogram
An echocardiogram is one of the most useful tests for heart failure.
It measures:
- Ejection fraction
- Chamber size
- Valve function
- Wall motion
- Ventricular thickness
- Pulmonary pressures
- Pericardial fluid
It helps separate HFrEF from HFpEF.
Stress Test
A stress test checks how the heart works during exercise or medication-induced stress. It may help identify coronary artery disease or ischemia as a cause of heart failure.
Cardiac Catheterization
Cardiac catheterization checks blood flow in coronary arteries and heart pressures. It may be used when coronary artery disease, valve disease or unexplained heart failure is suspected.
Heart Failure Medicines
Heart failure medicine depends on the type of heart failure, kidney function, blood pressure, potassium level and symptoms.
Guideline-directed medical therapy for HFrEF includes four major medication groups: ARNI or ACE inhibitor or ARB, evidence-based beta blocker, mineralocorticoid receptor antagonist and SGLT2 inhibitor.
ACE Inhibitors and ARBs
ACE inhibitors and ARBs help lower blood pressure and reduce afterload. This makes it easier for the heart to pump.
Examples include:
| Class | Examples | Key Point |
| ACE inhibitor | Lisinopril, enalapril | Watch cough, angioedema, kidney function |
| ARB | Losartan, valsartan | Often used if ACE inhibitor is not tolerated |
ACE inhibitor names often end in -pril.
ARB names often end in -sartan.
Nursing Considerations
Monitor:
- Blood pressure
- Potassium
- Creatinine
- Dizziness
- Cough with ACE inhibitors
- Angioedema signs
ARBs can increase potassium levels, so potassium monitoring matters.
ARNI Medicines
ARNI means angiotensin receptor-neprilysin inhibitor. Sacubitril/valsartan is an example.
It helps reduce strain on the heart and is commonly used in eligible patients with HFrEF.
Important nursing points include:
- Monitor blood pressure
- Monitor kidney function
- Monitor potassium
- Do not combine with ACE inhibitor
- Follow washout instructions when switching from ACE inhibitor
Beta Blockers
Beta blockers reduce heart rate, blood pressure and workload on the heart.
Common heart failure beta blockers include:
- Metoprolol succinate
- Carvedilol
- Bisoprolol
Beta blocker names often end in -lol.
Nursing Considerations
Always check:
- Blood pressure
- Heart rate
- Signs of worsening fluid overload
- Dizziness
- Fatigue
- Bronchospasm risk in susceptible patients
Beta blockers can mask signs of hypoglycemia in diabetic patients.
Mineralocorticoid Receptor Antagonists
MRAs help block aldosterone and reduce harmful fluid and sodium retention.
Examples include:
- Spironolactone
- Eplerenone
They can improve outcomes in selected HFrEF patients.
Nursing Considerations
Monitor:
- Potassium
- Kidney function
- Blood pressure
- Breast tenderness with spironolactone
- Dehydration signs
Spironolactone is potassium-sparing, so hyperkalemia is a key risk.
SGLT2 Inhibitors
SGLT2 inhibitors were first used for diabetes, but they also help many heart failure patients.
Examples include:
- Dapagliflozin
- Empagliflozin
The 2023 ESC focused update gave SGLT2 inhibitors strong recommendations for heart failure with mildly reduced or preserved ejection fraction, based on newer trial evidence.
Nursing Considerations
Monitor:
- Dehydration
- Genital infections
- Kidney function
- Blood glucose if diabetic
- Ketoacidosis warning signs in high-risk patients
Diuretics
Diuretics remove excess fluid from the body. They reduce swelling, lung congestion and shortness of breath.
| Type | Examples | Key Point |
| Loop diuretics | Furosemide, torsemide, bumetanide | Potassium-wasting |
| Thiazide diuretics | Hydrochlorothiazide, metolazone | Used in selected fluid cases |
| Potassium-sparing | Spironolactone | Raises potassium risk |
Nursing Considerations
Monitor:
- Blood pressure
- Daily weight
- Strict intake and output
- Potassium
- Sodium
- Kidney function
- Dehydration
- Dizziness
- Fall risk
Always check blood pressure before giving diuretics when ordered by protocol.
Digoxin
Digoxin is a positive inotropic medicine. It helps increase heart contractility and slows some heart rhythms.
It may be used in selected patients with heart failure and atrial fibrillation.
Nursing Considerations
Before giving digoxin, check:
- Apical pulse
- Heart rhythm
- Potassium level
- Kidney function
- Digoxin level if ordered
- Symptoms of toxicity
Low potassium increases risk of digoxin toxicity.
Signs of digoxin toxicity may include:
- Nausea
- Vomiting
- Loss of appetite
- Confusion
- Visual changes
- Bradycardia
- Arrhythmias
Calcium Channel Blockers
Calcium channel blockers relax blood vessels and lower blood pressure. Examples include diltiazem, nifedipine and verapamil.
Important point: Non-dihydropyridine calcium channel blockers, such as diltiazem and verapamil, are generally avoided in many patients with HFrEF because they can worsen systolic function. Use depends on the patient and provider order.
Nursing Considerations
Do not give without checking:
- Heart rate
- Blood pressure
- Dizziness
- Bradycardia
- Signs of worsening heart failure
Vasodilators
Vasodilators widen blood vessels and reduce preload or afterload.
Examples include:
- Nitroglycerin
- Hydralazine
- Isosorbide dinitrate
They may reduce cardiac workload and improve symptoms in selected patients.
Nursing Considerations
Monitor:
- Blood pressure
- Headache
- Dizziness
- Orthostatic hypotension
- Recent sildenafil or similar medicine use
Avoid nitrates when sildenafil or similar erectile dysfunction medicines were recently used, unless directed by a qualified clinician.
Heart Failure Medicine Summary Table
| Medicine Group | Main Action | Key Monitoring |
| ACE inhibitors | Lower afterload | BP, potassium, creatinine |
| ARBs | Lower afterload | BP, potassium, creatinine |
| ARNI | Reduces cardiac stress | BP, potassium, kidney function |
| Beta blockers | Reduce workload | BP, HR, fatigue |
| MRAs | Reduce aldosterone effects | Potassium, kidney function |
| SGLT2 inhibitors | Reduce HF hospitalization risk | Dehydration, kidney function |
| Diuretics | Remove excess fluid | Weight, I&O, electrolytes |
| Digoxin | Improves contractility in selected cases | Apical pulse, K+, toxicity |
| Vasodilators | Reduce preload and afterload | BP, dizziness |
Nursing Interventions for Heart Failure
Nursing care focuses on breathing, fluid balance, safety and medication response.
Priority interventions include:
- Give supplemental oxygen if ordered or needed
- Place the patient in High Fowler’s position
- Keep legs elevated when appropriate
- Apply fall precautions
- Monitor daily weight
- Monitor strict intake and output
- Assess vital signs
- Monitor heart rhythm
- Listen to lung sounds
- Assess edema
- Monitor response to diuretics
- Teach low-sodium diet
Why High Fowler’s Position Helps
High Fowler’s position keeps the head of the bed elevated. This helps lung expansion and reduces work of breathing.
It is especially helpful in left-sided heart failure with pulmonary congestion.
Daily Weight Monitoring
Daily weight is one of the best ways to track fluid retention.
Teach patients to:
- Weigh every morning
- Use the same scale
- Wear similar clothing
- Record the weight
- Report sudden weight gain as instructed
Sudden weight gain often means fluid retention before swelling becomes obvious.
Strict Intake and Output
Strict I&O helps measure fluid balance.
Monitor:
- Oral fluids
- IV fluids
- Urine output
- Drainage
- Vomiting or diarrhea
- Diuretic response
Poor urine output may suggest reduced kidney perfusion.
Diet for Heart Failure
Diet helps control fluid buildup and blood pressure.
Common recommendations include:
- Low sodium diet
- Reduced saturated fat
- Fluid restriction if prescribed
- Avoid high-sodium processed foods
- Limit alcohol
- Maintain balanced nutrition
The image highlights sodium intake below 2 grams per day. Sodium goals vary by provider and patient condition, but sodium restriction is often used to reduce fluid retention.
Foods to Limit
Avoid or reduce:
- Fried foods
- Processed meats
- Packaged snacks
- Canned soups
- Canned vegetables with salt
- Fast food
- Pickles
- Salted chips
- Instant noodles
- OTC medicines that contain sodium
Better Food Choices
Choose more:
- Fresh fruits
- Fresh vegetables
- Whole grains
- Beans and lentils, if potassium plan allows
- Unsalted nuts
- Lean proteins
- Low-sodium meals
- Home-cooked food with less salt
Fluid Restriction
Some patients need fluid restriction, especially when they have severe fluid overload or low sodium levels.
Fluids include:
- Water
- Tea
- Coffee
- Juice
- Soup
- Ice
- Gelatin
- Milk
Follow the exact provider order.
Patient Education for Heart Failure
Teach patients to follow a daily plan.
Key education points:
- Take medicines as prescribed
- Do not stop medicines without advice
- Track daily weight
- Limit sodium
- Follow fluid limits if prescribed
- Avoid excess alcohol
- Stop smoking
- Keep follow-up appointments
- Get vaccines as advised
- Report worsening symptoms early
- Stay active within safe limits
When to Call the Doctor
Patients should call their healthcare provider for:
- Sudden weight gain
- More swelling
- Increased shortness of breath
- More pillows needed to sleep
- New cough
- Dizziness after medicines
- Reduced urination
- Palpitations
- Fatigue that worsens
- Mild chest discomfort
When to Seek Emergency Care
Emergency care is needed for:
- Severe shortness of breath
- Chest pain
- Fainting
- Pink frothy sputum
- Confusion
- Blue lips
- Severe weakness
- Very fast or irregular heartbeat with symptoms
Complications of Heart Failure
Heart failure can lead to:
- Pulmonary edema
- Kidney dysfunction
- Liver congestion
- Arrhythmias
- Blood clots
- Stroke
- Cardiogenic shock
- Frequent hospitalization
- Sudden cardiac death
Early treatment and close monitoring reduce these risks.
Heart Failure Quick Review Table
| Topic | Key Point |
| Definition | Heart cannot fill or pump effectively |
| Main result | Decreased cardiac output |
| Left-sided signs | Dyspnea, crackles, fatigue |
| Right-sided signs | Edema, ascites, JVD |
| Key blood test | BNP or NT-proBNP |
| Key imaging test | Echocardiogram |
| Normal EF | Often 55% to 70% |
| Reduced EF | 40% or less |
| Nursing priority | Breathing and fluid balance |
| Diet focus | Low sodium and fluid control if prescribed |
FAQs
1. What is heart failure?
Heart failure is a condition where the heart cannot fill with blood or pump blood effectively enough to meet the body’s needs. It causes reduced cardiac output and fluid buildup. The heart may be weak, stiff or overloaded. Symptoms can include shortness of breath, fatigue and swelling.
2. What is the difference between left-sided and right-sided heart failure?
Left-sided heart failure causes blood to back up into the lungs. This leads to dyspnea, crackles, fatigue and sometimes pink frothy sputum. Right-sided heart failure causes blood to back up into the body. This leads to peripheral edema, ascites, jugular venous distention and hepatomegaly.
3. What causes heart failure?
Heart failure can be caused by coronary artery disease, myocardial infarction, hypertension, cardiomyopathy, valve disease, endocarditis, congenital heart disease and arrhythmias. Alcohol or drug use can also damage the heart. Long-term high blood pressure is a major risk factor. The exact cause should be identified to guide treatment.
4. What is BNP in heart failure?
BNP is a biomarker released when the ventricles stretch from pressure or fluid overload. Higher BNP levels can support a heart failure diagnosis. BNP must be interpreted with symptoms, age, kidney function and other medical conditions. It is helpful but not the only test used.
5. What is ejection fraction?
Ejection fraction is the percentage of blood pumped out of the left ventricle with each heartbeat. A normal EF is often around 55% to 70%. An EF of 40% or less usually means reduced ejection fraction. Echocardiography is commonly used to measure EF.
6. What medicines are used for heart failure?
Common medicines include ACE inhibitors, ARBs, ARNIs, beta blockers, MRAs, SGLT2 inhibitors, diuretics, digoxin and vasodilators. The best medicine plan depends on the type of heart failure and patient condition. HFrEF has strong evidence-based medication groups. Patients should take medicines only as prescribed.
7. Why are diuretics used in heart failure?
Diuretics remove excess fluid from the body. They help reduce swelling, lung congestion and shortness of breath. Loop diuretics such as furosemide can lower potassium, so labs need monitoring. Patients also need blood pressure checks and daily weight tracking.
8. Why should nurses check BP and heart rate before heart failure medicines?
Many heart failure medicines lower blood pressure, heart rate or both. Giving them when BP or HR is too low can worsen dizziness, falls or poor perfusion. Beta blockers especially require heart rate and blood pressure checks. Diuretics and vasodilators also need blood pressure monitoring.
9. What diet is best for heart failure?
A heart failure diet often focuses on low sodium, balanced nutrition and fluid control if prescribed. Patients should reduce processed foods, fried foods, canned soups, salty snacks and fast food. Fresh foods and home-cooked meals with less salt are better choices. Sodium goals should follow the provider’s plan.
10. What are danger signs of worsening heart failure?
Danger signs include severe shortness of breath, pink frothy sputum, chest pain, fainting, confusion, blue lips and sudden severe swelling. Sudden weight gain can also mean fluid retention. More pillows needed to sleep may signal worsening congestion. These symptoms need prompt medical attention.
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