Heart Failure: Causes, Symptoms, Management

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Introduction

Heart failure is a complex clinical syndrome in which the heart is unable to pump sufficient blood to meet the metabolic demands of the body, or can do so only at the expense of abnormally elevated filling pressures. It does not mean that the heart has completely stopped working. Rather, the heart's pumping or filling ability has become impaired enough to produce symptoms, functional limitations, or evidence of congestion.

Heart failure is one of the most important cardiovascular disorders encountered in clinical practice. It can develop suddenly, as in acute myocardial infarction or severe myocarditis, or gradually over years because of hypertension, coronary artery disease, valvular disease, cardiomyopathy, diabetes, or other systemic conditions. Modern understanding of heart failure has also expanded beyond reduced pumping function. A patient can have significant heart failure symptoms even when the left ventricular ejection fraction is preserved.

The clinical importance of heart failure lies not only in its symptoms but also in its tendency to progress, cause repeated hospitalization, impair quality of life, and increase mortality. Early recognition and appropriate treatment can substantially improve symptoms and outcomes. Current guideline-directed therapy for heart failure has become increasingly comprehensive, particularly for heart failure with reduced ejection fraction, where four major medication classes form the foundation of treatment.

Heart failure should therefore be viewed as a syndrome rather than a single disease. Identifying the underlying cause, determining the type and severity of heart failure, recognizing precipitating factors, and selecting evidence-based therapy are all essential components of management.

What Is Heart Failure?

Heart failure occurs when structural or functional abnormalities of the heart impair its ability to fill with blood or eject blood effectively. As cardiac output becomes inadequate, the body activates several compensatory mechanisms designed to maintain blood pressure and organ perfusion.

Initially, these mechanisms may be beneficial. However, persistent activation eventually becomes harmful. The sympathetic nervous system increases heart rate and contractility, the renin–angiotensin–aldosterone system promotes vasoconstriction and sodium and water retention, and antidiuretic hormone contributes to water retention. These responses increase the workload of the heart and contribute to progressive structural remodeling.

A patient may therefore develop two major physiological problems: inadequate forward blood flow and excessive backward pressure. Reduced forward flow can cause fatigue, weakness, exercise intolerance, renal dysfunction, and impaired tissue perfusion. Backward pressure can cause pulmonary congestion, dyspnea, orthopnea, elevated jugular venous pressure, peripheral edema, ascites, and hepatic congestion.

The syndrome may predominantly involve the left side, right side, or both sides of the heart. It may also be acute or chronic, compensated or decompensated, and associated with reduced, mildly reduced, or preserved left ventricular ejection fraction.

Normal Cardiac Function

Understanding normal cardiac physiology makes the pathophysiology of heart failure easier to appreciate.

The right side of the heart receives deoxygenated blood from the systemic circulation and pumps it into the pulmonary circulation. The left side receives oxygenated blood from the lungs and pumps it through the aorta into the systemic circulation.

The ventricles must perform two fundamental functions:

1. Diastolic function — the ability to relax and fill with blood.
2. Systolic function — the ability to contract and eject blood.

Cardiac output is determined by heart rate multiplied by stroke volume:

Cardiac output = Heart rate × Stroke volume

Stroke volume is influenced by preload, afterload, and myocardial contractility.

Preload refers broadly to ventricular filling and myocardial fiber stretch before contraction. Afterload represents the resistance against which the ventricle must eject blood. Contractility describes the intrinsic ability of cardiac muscle to generate force.

A healthy cardiovascular system continuously adjusts these variables according to the body's needs. During exercise, cardiac output increases substantially to provide skeletal muscles and other tissues with additional oxygen and nutrients.

In heart failure, one or more components of this system become abnormal.

Classification of Heart Failure

Heart failure can be classified in several clinically useful ways. One of the most important classifications is based on left ventricular ejection fraction.

Heart Failure With Reduced Ejection Fraction

Heart failure with reduced ejection fraction, or HFrEF, generally refers to heart failure with an LVEF of 40% or less.

This form is commonly associated with impaired systolic function. The left ventricle may become dilated and contract less effectively, resulting in reduced stroke volume.

Common causes include:

• Ischemic heart disease
• Previous myocardial infarction
• Dilated cardiomyopathy
• Myocarditis
• Genetic cardiomyopathies
• Certain cardiotoxic drugs
• Persistent tachyarrhythmias
• Severe valvular disease

HFrEF has particularly strong evidence supporting multidrug guideline-directed medical therapy. The modern foundation includes an angiotensin receptor-neprilysin inhibitor or appropriate renin–angiotensin system blocker, an evidence-based beta blocker, a mineralocorticoid receptor antagonist, and an SGLT2 inhibitor.

Heart Failure With Mildly Reduced Ejection Fraction

HFmrEF generally refers to an LVEF of approximately 41–49%, together with evidence supporting the presence of increased cardiac filling pressures.

Patients in this category can have characteristics overlapping with both HFrEF and HFpEF. Treatment is individualized according to the underlying disease, comorbidities, symptoms, and evidence-based therapies.

SGLT2 inhibitors have an important role in this group, while other therapies may also be considered in selected patients.

Heart Failure With Preserved Ejection Fraction

HFpEF generally refers to an LVEF of 50% or greater with evidence of increased filling pressures.

A major misconception is that a normal ejection fraction excludes heart failure. Ejection fraction measures the percentage of blood ejected from the ventricle during systole; it does not directly measure whether the ventricle relaxes normally or whether filling pressures are elevated.

In HFpEF, the ventricle may become stiff and less compliant. It can therefore have difficulty accepting blood during diastole without a substantial increase in filling pressure.

HFpEF is frequently associated with:

• Hypertension
• Obesity
• Diabetes mellitus
• Chronic kidney disease
• Atrial fibrillation
• Older age
• Coronary artery disease
• Valvular disease

SGLT2 inhibitors have become an important evidence-based treatment option for patients with HFpEF, while management of blood pressure, atrial fibrillation, ischemic disease, obesity, diabetes, and other comorbidities remains central to care.

Heart Failure With Improved Ejection Fraction

Some patients initially have an LVEF of 40% or less and subsequently demonstrate an LVEF above 40% after treatment.

This is referred to as heart failure with improved ejection fraction, or HFimpEF.

Improvement in ejection fraction does not necessarily mean that the underlying disease has permanently disappeared. Withdrawal of effective therapy can result in recurrence of ventricular dysfunction. Current guidance therefore recommends continuing appropriate HFrEF treatment in patients whose ejection fraction has improved.

Acute and Chronic Heart Failure

Heart failure can also be divided into acute and chronic forms.

Chronic heart failure develops and persists over time. Symptoms may remain relatively stable for months or years, although episodes of worsening can occur.

Acute heart failure develops rapidly or represents an acute worsening of pre-existing chronic heart failure. It may cause severe pulmonary congestion, hypoxemia, hypotension, or cardiogenic shock.

Acute decompensation can be triggered by many factors, including:

• Acute coronary syndrome
• Uncontrolled hypertension
• Arrhythmias
• Infection
• Medication non-adherence
• Excessive dietary sodium or fluid intake
• Renal deterioration
• Pulmonary embolism
• Severe anemia
• Thyroid disorders
• Valvular deterioration
• Myocarditis

The distinction is clinically important because acute heart failure often requires urgent assessment and treatment.

Causes of Heart Failure

Heart failure has numerous causes, and identifying the cause is fundamental because treatment may differ considerably according to the underlying disease.

Coronary Artery Disease

Coronary artery disease is one of the most important causes of heart failure. Repeated ischemia or myocardial infarction can damage ventricular muscle and reduce contractile function.

Following myocardial infarction, dead myocardial tissue is replaced by scar tissue. Scarred myocardium does not contract normally, and the remaining myocardium may undergo compensatory enlargement and remodeling.

Over time, ventricular dilation and changes in myocardial geometry can worsen systolic function.

Hypertension

Long-standing hypertension places increased pressure load on the left ventricle.

Initially, the ventricular wall becomes thicker through hypertrophic remodeling. This adaptation helps normalize wall stress, but the thickened myocardium can become stiff and impair diastolic relaxation.

Persistent hypertension may eventually lead to ventricular dilation, systolic dysfunction, and clinical heart failure.

Valvular Heart Disease

Diseases of the heart valves can produce chronic pressure or volume overload.

Aortic stenosis creates pressure overload because the left ventricle must generate higher pressure to eject blood through the narrowed valve.

Aortic or mitral regurgitation produces volume overload because part of the blood moves backward rather than efficiently forward.

Mitral stenosis can increase left atrial and pulmonary pressures, eventually contributing to pulmonary hypertension and right-sided dysfunction.

Cardiomyopathies

Cardiomyopathies are diseases primarily affecting the myocardium.

Important forms include:

• Dilated cardiomyopathy
• Hypertrophic cardiomyopathy
• Restrictive cardiomyopathy
• Arrhythmogenic cardiomyopathy

They may be genetic, inflammatory, metabolic, toxic, or idiopathic.

Myocarditis

Myocarditis is inflammation of the myocardium. It can occur after viral infections and may also result from autoimmune disorders, toxins, or other infectious causes.

Myocardial inflammation can impair contractility and occasionally lead to severe acute heart failure.

Arrhythmias

Persistent tachycardia can reduce ventricular filling time and increase myocardial oxygen demand. Sustained tachyarrhythmias can eventually produce tachycardia-induced cardiomyopathy.

Severe bradycardia can also reduce cardiac output.

Atrial fibrillation may worsen heart failure through loss of coordinated atrial contraction, rapid ventricular response, and irregular ventricular filling.

Congenital Heart Disease

Congenital structural abnormalities can create abnormal pressure or volume loads on the heart.

Some patients develop heart failure during childhood, while others remain relatively stable until adulthood.

Endocrine and Metabolic Disorders

Several systemic conditions can contribute to cardiac dysfunction.

These include:

• Thyroid disease
• Diabetes mellitus
• Severe obesity
• Nutritional deficiencies
• Hemochromatosis
• Amyloidosis
• Chronic kidney disease
• Severe anemia

Some metabolic disorders directly affect myocardial function, whereas others increase cardiovascular workload.

Toxins and Medications

Certain substances can damage cardiac muscle.

Alcohol is an important example of a potentially cardiotoxic exposure when consumed excessively over prolonged periods.

Some cancer therapies can also produce myocardial injury. Patients receiving potentially cardiotoxic treatment may therefore require cardiovascular assessment and monitoring.

Risk Factors for Heart Failure

Many risk factors are modifiable.

Major risk factors include:

• Hypertension
• Coronary artery disease
• Diabetes mellitus
• Obesity
• Smoking
• Physical inactivity
• Dyslipidemia
• Excessive alcohol consumption
• Chronic kidney disease
• Sleep-disordered breathing
• Certain cardiotoxic medications
• Family history of cardiomyopathy

Prevention is particularly important because heart failure often develops after years of cardiovascular risk exposure.

The modern ACC/AHA framework emphasizes stages beginning before symptomatic disease. Stage A includes people at risk for heart failure, while Stage B describes pre-heart failure in individuals with structural or functional abnormalities or relevant biomarkers but without current or previous heart failure symptoms. Symptomatic disease is Stage C, and advanced disease is Stage D.

Pathophysiology of Heart Failure

The pathophysiology of heart failure involves a complex interaction between mechanical dysfunction, neurohormonal activation, vascular changes, renal responses, inflammation, and ventricular remodeling.

When cardiac output falls, arterial pressure and effective circulating volume may decrease. The body interprets this as inadequate perfusion.

The sympathetic nervous system becomes activated.

This produces:

• Increased heart rate
• Increased myocardial contractility
• Peripheral vasoconstriction
• Redistribution of blood flow

At the same time, reduced renal perfusion stimulates the renin–angiotensin–aldosterone system.

Renin ultimately contributes to formation of angiotensin II, which produces vasoconstriction and promotes aldosterone release. Aldosterone increases sodium and water retention.

Antidiuretic hormone also contributes to water retention.

These mechanisms initially help maintain blood pressure and circulation. However, chronic activation increases afterload, fluid retention, myocardial oxygen demand, and ventricular stress.

Ventricular Remodeling

Persistent hemodynamic stress causes structural changes in the myocardium.

These changes may include:

• Ventricular dilation
• Hypertrophy
• Fibrosis
• Altered ventricular geometry
• Increased wall stress
• Progressive reduction in contractile efficiency

This process is called ventricular remodeling.

Remodeling can become a self-perpetuating process in which worsening ventricular structure produces worsening mechanical function, which then creates additional stress on the ventricle.

Left-Sided Heart Failure

Left-sided heart failure primarily affects the left ventricle and commonly produces pulmonary congestion.

When left ventricular filling pressures increase, pressure is transmitted backward into the left atrium and pulmonary veins.

As pulmonary capillary hydrostatic pressure rises, fluid can move into the pulmonary interstitium and, in severe cases, into the alveolar spaces.

This produces symptoms such as:

• Shortness of breath
• Orthopnea
• Paroxysmal nocturnal dyspnea
• Cough
• Reduced exercise tolerance
• Pulmonary crackles
• Hypoxemia in severe cases

Acute pulmonary edema can develop rapidly and represents a medical emergency.

Right-Sided Heart Failure

Right-sided heart failure causes systemic venous congestion.

The most common cause of isolated right-sided failure is often left-sided heart failure, although pulmonary hypertension, right ventricular infarction, congenital heart disease, and certain pulmonary disorders can also cause right-sided dysfunction.

Clinical findings may include:

• Elevated jugular venous pressure
• Peripheral edema
• Hepatomegaly
• Ascites
• Weight gain from fluid retention
• Hepatic congestion
• Positive hepatojugular reflux

When both ventricles are affected, the patient may develop biventricular heart failure.

Clinical Features of Heart Failure

Symptoms vary according to the severity, underlying cause, rate of progression, and side of the heart predominantly affected.

Dyspnea

Shortness of breath is one of the most characteristic symptoms.

Initially, it may occur only during exertion. As disease progresses, the patient may become breathless during ordinary activities and eventually even at rest.

Dyspnea results from elevated pulmonary pressures, impaired pulmonary compliance, increased work of breathing, and reduced cardiac reserve.

Orthopnea

Orthopnea refers to breathlessness that occurs when lying flat.

Patients may report needing several pillows to sleep comfortably.

When a person lies down, venous blood returns more readily to the thorax. In a patient with impaired cardiac function, the increased venous return may worsen pulmonary congestion.

Paroxysmal Nocturnal Dyspnea

Paroxysmal nocturnal dyspnea is sudden breathlessness that awakens a patient from sleep, typically after being asleep for some time.

The patient may need to sit or stand to breathe more comfortably.

This is different from simply becoming mildly short of breath immediately after lying down.

Fatigue

Reduced cardiac output and impaired skeletal muscle perfusion can produce profound fatigue.

Patients may report that ordinary activities such as climbing stairs, walking, bathing, or household tasks have become increasingly difficult.

Peripheral Edema

Fluid accumulation in the legs and ankles is common, particularly in right-sided or biventricular failure.

Edema may be worse toward the end of the day and improve after overnight recumbency.

Weight Gain

Rapid weight gain can indicate fluid accumulation.

A patient may gain several kilograms over a short period without a corresponding increase in food intake.

Cough and Wheezing

Pulmonary congestion can cause cough and sometimes wheezing.

Cardiac wheezing may occasionally resemble bronchial asthma, creating diagnostic confusion.

Reduced Exercise Capacity

Patients with heart failure frequently notice a progressive reduction in exercise tolerance.

Activities that were previously easy become increasingly difficult.

The New York Heart Association functional classification is commonly used to describe the effect of symptoms on physical activity.

New York Heart Association Functional Classification

Class I

There is no limitation of ordinary physical activity. Ordinary activity does not produce significant symptoms.

Class II

There is mild limitation of physical activity. The patient is comfortable at rest, but ordinary activity can produce symptoms.

Class III

There is marked limitation of physical activity. The patient remains comfortable at rest, but less-than-ordinary activity produces symptoms.

Class IV

The patient is unable to perform physical activity without discomfort, and symptoms may be present even at rest.

NYHA classification is useful for describing functional limitation and monitoring changes over time.

Physical Examination

A careful cardiovascular examination can provide important clues.

General Appearance

Patients with severe heart failure may appear breathless, fatigued, anxious, or poorly perfused.

In advanced low-output states, the extremities may become cool.

Blood Pressure

Blood pressure may be normal, elevated, or low.

Hypertension may contribute to acute pulmonary edema, whereas severe hypotension can indicate advanced pump failure or cardiogenic shock.

Pulse

Tachycardia may occur because of sympathetic activation.

An irregular pulse may suggest atrial fibrillation or another arrhythmia.

Jugular Venous Pressure

An elevated jugular venous pressure is an important indicator of increased right atrial pressure and systemic venous congestion.

Heart Sounds

A third heart sound, or S3, may be present in patients with volume-overloaded ventricles and systolic heart failure.

A fourth heart sound, or S4, can occur with a stiff ventricle and impaired relaxation, although it requires sinus rhythm for generation.

Murmurs may indicate underlying valvular disease.

Lung Examination

Fine inspiratory crackles may occur when pulmonary interstitial or alveolar fluid is present.

However, the absence of crackles does not completely exclude heart failure.

Peripheral Edema

Pitting edema of the lower limbs suggests extracellular fluid accumulation.

In severe systemic congestion, edema can extend proximally and may be associated with ascites.

Diagnosis of Heart Failure

Diagnosis requires integration of history, physical examination, laboratory testing, imaging, and assessment of cardiac function.

No single test is sufficient in every patient.

The clinician should establish:

1. Whether heart failure is actually present.
2. What caused it.
3. What type of heart failure is present.
4. How severe it is.
5. Whether there is an acute precipitating factor.
6. Which complications and comorbidities require treatment.

Electrocardiography

A 12-lead ECG should generally be obtained in suspected heart failure.

It can identify:

• Previous myocardial infarction
• Ischemia
• Atrial fibrillation
• Other arrhythmias
• Conduction abnormalities
• Left ventricular hypertrophy
• Bundle branch block

Although an abnormal ECG does not by itself establish heart failure, it can provide important information about the underlying cardiac disease.

Chest X-Ray

Chest radiography may demonstrate findings associated with pulmonary congestion.

Possible findings include:

• Cardiomegaly
• Pulmonary vascular redistribution
• Interstitial edema
• Kerley B lines
• Pleural effusions
• Alveolar pulmonary edema

Chest X-ray is also useful for identifying alternative causes of dyspnea, such as pneumonia or significant pulmonary disease.

Echocardiography

Echocardiography is one of the most important investigations in heart failure.

It provides information about:

• Left ventricular ejection fraction
• Ventricular size
• Wall thickness
• Regional wall motion
• Diastolic function
• Valvular abnormalities
• Right ventricular function
• Pulmonary pressures
• Pericardial disease

Echocardiography is particularly important for determining the phenotype of heart failure.

The ejection fraction is calculated as:

EF = (End-diastolic volume − End-systolic volume) / End-diastolic volume × 100

A normal or preserved EF does not automatically exclude heart failure because filling abnormalities and elevated intracardiac pressures may still be present.

Natriuretic Peptides

The major natriuretic peptides used clinically are:

• BNP
• NT-proBNP

These biomarkers are released in response to myocardial wall stress.

They can be particularly useful when the diagnosis is uncertain in a patient presenting with dyspnea.

Elevated concentrations support the possibility of heart failure, but interpretation requires clinical context.

Natriuretic peptide levels can also be affected by factors such as renal dysfunction, atrial fibrillation, age, obesity, and other cardiovascular conditions.

Blood Investigations

Laboratory testing helps identify contributing conditions and treatment-related risks.

Common investigations include:

• Complete blood count
• Serum electrolytes
• Urea and creatinine
• Estimated glomerular filtration rate
• Liver function tests
• Glucose
• HbA1c
• Thyroid function tests
• Lipid profile
• Iron studies when indicated
• Natriuretic peptides when appropriate

Troponin testing is particularly important when acute coronary syndrome or myocardial injury is suspected.

Cardiac Magnetic Resonance Imaging

Cardiac MRI can provide detailed information about myocardial structure and tissue characteristics.

It is particularly useful in selected patients with suspected:

• Myocarditis
• Infiltrative cardiomyopathy
• Cardiac amyloidosis
• Sarcoidosis
• Specific cardiomyopathies
• Myocardial scar

It can also help distinguish ischemic from non-ischemic patterns of myocardial injury.

Coronary Assessment

Patients with suspected ischemic cardiomyopathy may require coronary evaluation.

Depending on the clinical situation, this may include:

• CT coronary angiography
• Invasive coronary angiography
• Functional ischemia testing

Identifying significant coronary disease is important because revascularization may be appropriate in selected patients.

Treatment Goals in Heart Failure

Treatment should address several objectives simultaneously.

The major goals are:

• Relieve symptoms
• Reduce congestion
• Improve functional capacity
• Reduce hospitalization
• Slow disease progression
• Improve survival
• Treat the underlying cause
• Manage comorbidities
• Improve quality of life

Treatment differs according to the phenotype of heart failure.

Lifestyle and Self-Care

Lifestyle measures complement medical therapy.

Patients should receive individualized advice regarding:

• Dietary habits
• Physical activity
• Weight monitoring
• Medication adherence
• Smoking cessation
• Alcohol avoidance or reduction where appropriate
• Vaccination
• Recognition of worsening symptoms

Dietary sodium restriction may be recommended in selected patients, particularly when congestion is difficult to control.

Fluid restriction is not automatically required for every patient with chronic heart failure. It may be considered in selected patients with significant congestion or hyponatremia according to the clinical situation.

Diuretics

Diuretics are central to the treatment of fluid overload.

Loop diuretics such as:

• Furosemide
• Bumetanide
• Torsemide

increase renal sodium and water excretion.

They can rapidly reduce pulmonary and peripheral congestion and improve symptoms.

However, diuretics primarily provide symptomatic relief and do not replace disease-modifying therapy.

Excessive diuresis can produce:

• Hypotension
• Dehydration
• Hypokalemia
• Hyponatremia
• Worsening renal function

Therefore, renal function, electrolytes, blood pressure, body weight, and clinical volume status should be monitored.

The Four Major Pillars in HFrEF

For patients with HFrEF, modern guideline-directed medical therapy is built around four major medication classes.

These are:

1. ARNI or appropriate renin–angiotensin system inhibition
2. Evidence-based beta blocker
3. Mineralocorticoid receptor antagonist
4. SGLT2 inhibitor

The 2022 AHA/ACC/HFSA guideline specifically identifies these four medication classes as the foundation of contemporary HFrEF guideline-directed therapy.

Recent clinical practice has increasingly emphasized starting foundational therapies promptly and titrating them according to tolerance rather than delaying every medication until another drug has reached its target dose.

Angiotensin Receptor-Neprilysin Inhibitors

Sacubitril/valsartan is the principal ARNI used in HFrEF.

Sacubitril inhibits neprilysin, increasing the activity of beneficial natriuretic peptides. Valsartan blocks the angiotensin II receptor.

The combined effects include:

• Reduced vasoconstriction
• Reduced sodium retention
• Reduced maladaptive neurohormonal signaling
• Reduced ventricular remodeling
• Improved clinical outcomes in appropriate HFrEF patients

ACE inhibitors or ARBs remain important alternatives when ARNI therapy is not appropriate or tolerated.

Beta Blockers

Evidence-based beta blockers used in HFrEF include:

• Carvedilol
• Metoprolol succinate
• Bisoprolol

These medications reduce chronic sympathetic stimulation.

They can:

• Reduce heart rate
• Decrease myocardial oxygen demand
• Improve ventricular remodeling
• Reduce arrhythmic risk
• Improve survival in appropriate HFrEF patients

Beta blockers should generally be initiated when the patient is clinically stable and then gradually titrated.

Starting or increasing them during severe acute congestion or hemodynamic instability may be inappropriate.

Mineralocorticoid Receptor Antagonists

Examples include:

• Spironolactone
• Eplerenone

These medications block aldosterone-mediated effects.

They can reduce sodium retention, myocardial fibrosis, and adverse remodeling.

The major safety concerns include:

• Hyperkalemia
• Worsening renal function

Serum potassium and renal function therefore require appropriate monitoring.

SGLT2 Inhibitors

SGLT2 inhibitors such as:

• Dapagliflozin
• Empagliflozin

have become an important component of heart failure therapy.

Their benefits extend beyond glucose lowering.

They can reduce the risk of heart failure hospitalization and provide cardiovascular and renal benefits in appropriate patients.

Importantly, SGLT2 inhibitors are useful in heart failure even when the patient does not have diabetes. Current evidence and guidelines support their use across multiple heart failure phenotypes, including HFmrEF and HFpEF.

Other Pharmacological Therapies

Additional medications may be appropriate for selected patients.

Ivabradine

Ivabradine reduces sinus node firing and can be considered in selected patients with HFrEF who remain in sinus rhythm with an elevated resting heart rate despite appropriate therapy.

Hydralazine and Isosorbide Dinitrate

This combination provides an alternative strategy for selected patients who cannot tolerate standard renin–angiotensin system inhibition and has particular evidence in certain populations.

Digoxin

Digoxin may be considered in selected patients, particularly when symptoms or atrial fibrillation require additional rate-control considerations.

Because of its narrow therapeutic range, careful dosing and monitoring are important.

Anticoagulation

Heart failure alone is not an automatic indication for anticoagulation.

However, anticoagulation may be required when another indication exists, such as atrial fibrillation with an appropriate thromboembolic risk profile or venous thromboembolism.

Treatment of HFpEF

HFpEF requires a somewhat different therapeutic strategy.

Because the ejection fraction is preserved, simply attempting to increase ventricular contraction is not the central approach.

Treatment focuses on:

• Controlling blood pressure
• Managing fluid congestion
• Treating atrial fibrillation
• Managing coronary disease
• Managing diabetes
• Addressing obesity
• Treating sleep-disordered breathing when appropriate
• Managing chronic kidney disease
• Using evidence-based heart failure therapies

SGLT2 inhibitors have an important role in HFpEF. MRAs and ARNI therapy may be considered in selected patients, depending on the clinical phenotype and guideline recommendations.

Management of Comorbidities

Heart failure rarely exists in isolation.

Common associated conditions include:

• Hypertension
• Diabetes mellitus
• Chronic kidney disease
• Atrial fibrillation
• Coronary artery disease
• Anemia
• Iron deficiency
• Obesity
• Sleep-disordered breathing
• Thyroid disease

These conditions can worsen heart failure and should be actively identified and managed.

Current guidelines specifically address several of these comorbidities, including iron deficiency, anemia, hypertension, sleep disorders, type 2 diabetes, atrial fibrillation, coronary artery disease, and malignancy.

Iron Deficiency and Anemia

Iron deficiency is common in patients with heart failure and can worsen fatigue and exercise intolerance.

Anemia may also reduce oxygen delivery to tissues and increase cardiac workload.

Patients with heart failure and suspected iron deficiency should therefore undergo appropriate evaluation.

In selected patients, intravenous iron therapy may be considered according to the clinical phenotype and current evidence.

Heart Failure and Atrial Fibrillation

Atrial fibrillation and heart failure frequently coexist.

Each condition can worsen the other.

Loss of coordinated atrial contraction can impair ventricular filling, particularly in patients with stiff ventricles.

Rapid ventricular rates can further reduce cardiac efficiency.

Management may include:

• Rate control
• Rhythm control in selected patients
• Anticoagulation when indicated
• Treatment of underlying structural heart disease
• Optimization of heart failure therapy

Device Therapy

Some patients require device-based treatment despite optimized medical therapy.

Implantable Cardioverter-Defibrillator

An ICD may be indicated in selected patients with significant systolic dysfunction who meet established criteria.

Its major purpose is prevention of sudden cardiac death from malignant ventricular arrhythmias.

Cardiac Resynchronization Therapy

Cardiac resynchronization therapy, or CRT, can improve ventricular coordination in selected patients with reduced ejection fraction and appropriate electrical conduction abnormalities.

CRT may improve:

• Symptoms
• Ventricular function
• Exercise capacity
• Hospitalization risk
• Survival in appropriately selected patients

Patient selection depends on ejection fraction, rhythm, QRS characteristics, symptom severity, and other clinical factors.

Revascularization

Patients with heart failure caused or worsened by coronary artery disease may benefit from revascularization.

Coronary revascularization can improve blood flow to viable myocardium and may improve outcomes in appropriately selected patients.

The decision depends on:

• Coronary anatomy
• Ischemic burden
• Ventricular function
• Myocardial viability
• Symptoms
• Overall surgical or procedural risk

Valvular Intervention

Heart failure may result from severe valvular disease or may be aggravated by it.

Treatment can include:

• Surgical valve replacement
• Surgical valve repair
• Transcatheter valve procedures

The choice depends on the affected valve, severity, symptoms, ventricular function, anatomy, surgical risk, and multidisciplinary assessment.

In selected patients with HFrEF and severe secondary mitral regurgitation, intervention may be considered after optimization of guideline-directed therapy.

Acute Decompensated Heart Failure

Acute decompensated heart failure is a sudden worsening of heart failure requiring urgent assessment.

The patient may present with:

• Severe dyspnea
• Orthopnea
• Pulmonary edema
• Peripheral edema
• Hypoxemia
• Tachycardia
• Hypertension or hypotension
• Reduced urine output
• Altered mental status in severe cases

The first priority is stabilization.

The clinician should rapidly evaluate airway, breathing, circulation, oxygenation, blood pressure, rhythm, and evidence of pulmonary or systemic congestion.

Acute Pulmonary Edema

Acute pulmonary edema is characterized by rapid accumulation of fluid in the lungs.

Patients may have:

• Severe breathlessness
• Orthopnea
• Hypoxemia
• Tachypnea
• Crackles
• Anxiety or agitation
• Cough
• Frothy sputum in severe cases

Treatment depends on the underlying hemodynamic state.

In patients with significant congestion, intravenous loop diuretics are commonly used.

When blood pressure is sufficiently high, vasodilator therapy may help reduce preload and afterload in appropriate patients.

Oxygen should be administered when clinically indicated, and ventilatory support may be required in severe respiratory distress.

Cardiogenic Shock

Cardiogenic shock represents severe cardiac pump failure resulting in inadequate tissue perfusion.

Possible findings include:

• Hypotension
• Cold extremities
• Altered mental status
• Oliguria
• Elevated lactate
• Severe pulmonary congestion or other evidence of heart failure
• Weak pulse
• Multi-organ dysfunction

Cardiogenic shock requires emergency management and specialist involvement.

Treatment may involve:

• Hemodynamic stabilization
• Treatment of the underlying cause
• Revascularization when appropriate
• Vasopressors in selected patients
• Inotropes in selected circumstances
• Mechanical circulatory support in carefully selected patients

Common Precipitants of Decompensation

A patient with previously stable chronic heart failure may suddenly deteriorate.

Common triggers include:

Infection: systemic infection increases metabolic demand and may destabilize cardiovascular function.

Medication non-adherence: stopping diuretics or disease-modifying therapy can cause worsening congestion or loss of cardiovascular protection.

Excess sodium intake: sodium retention promotes fluid accumulation.

Arrhythmia: atrial fibrillation with rapid ventricular response or ventricular arrhythmias can rapidly reduce cardiac efficiency.

Acute coronary syndrome: new myocardial ischemia or infarction can severely impair ventricular function.

Hypertensive crisis: sudden elevation in afterload can precipitate pulmonary edema.

Renal dysfunction: impaired renal sodium and water handling can worsen congestion.

Pulmonary embolism: acute right ventricular strain can cause sudden deterioration.

Complications of Heart Failure

Heart failure can affect nearly every organ system.

Important complications include:

• Pulmonary edema
• Arrhythmias
• Sudden cardiac death
• Thromboembolism
• Stroke
• Renal dysfunction
• Hepatic congestion
• Electrolyte abnormalities
• Pulmonary hypertension
• Cardiac cachexia
• Recurrent hospitalization
• Cardiogenic shock

The severity of complications depends on the underlying cause and stage of disease.

Renal Dysfunction in Heart Failure

The heart and kidneys are closely interconnected.

Reduced cardiac output can decrease renal perfusion, while venous congestion can increase renal venous pressure.

At the same time, neurohormonal activation promotes sodium and water retention.

This interaction is sometimes referred to as the cardiorenal syndrome.

Treatment therefore requires a balance between relieving congestion and maintaining adequate renal perfusion and electrolyte stability.

A modest rise in creatinine does not automatically mean that effective heart failure therapy must be stopped; clinical context, volume status, blood pressure, potassium, and the trajectory of renal function must be considered.

Electrolyte Abnormalities

Heart failure and its treatment can produce electrolyte abnormalities.

Loop diuretics may cause:

• Hypokalemia
• Hyponatremia
• Hypomagnesemia

Mineralocorticoid receptor antagonists can cause:

• Hyperkalemia

Renal dysfunction can further complicate electrolyte management.

Severe potassium abnormalities can provoke dangerous cardiac arrhythmias, making laboratory monitoring essential.

Prevention of Heart Failure

Prevention begins before symptoms develop.

The most effective strategies include:

• Controlling blood pressure
• Preventing and treating coronary artery disease
• Maintaining healthy body weight
• Regular physical activity
• Avoiding tobacco
• Managing diabetes
• Treating dyslipidemia
• Limiting harmful alcohol exposure
• Managing sleep disorders
• Monitoring patients receiving potentially cardiotoxic therapies
• Recognizing individuals with genetic or familial cardiomyopathy risk

The emphasis on prevention is reflected in modern heart failure staging, which identifies people who are at risk before symptomatic heart failure develops.

Patient Monitoring

Long-term monitoring is essential.

Patients should be assessed for:

• New or worsening dyspnea
• Increasing edema
• Rapid weight gain
• Reduced exercise tolerance
• Orthopnea
• Medication adverse effects
• Blood pressure changes
• Renal function
• Electrolytes
• Heart rhythm
• Disease progression

Daily weight monitoring may be useful for selected patients, particularly those prone to recurrent fluid retention.

A sudden increase in weight over a short period can indicate increasing fluid accumulation and should prompt clinical assessment according to the patient's individualized action plan.

When Emergency Care Is Needed

Certain symptoms require urgent medical assessment.

These include:

• Severe or rapidly worsening breathlessness
• Breathlessness at rest
• New chest pain
• Fainting
• Severe weakness
• Blue or gray lips
• Confusion
• Coughing up significant amounts of pink or frothy sputum
• Severe palpitations associated with dizziness or collapse
• Very low blood pressure
• Markedly reduced urine output

Acute pulmonary edema, acute coronary syndrome, malignant arrhythmia, and cardiogenic shock can be life-threatening.

Advanced Heart Failure

Advanced heart failure refers to severe disease in which symptoms significantly interfere with daily life and may persist despite attempts to optimize evidence-based treatment.

Patients may experience:

• Severe exercise intolerance
• Recurrent hospitalizations
• Persistent congestion
• Progressive renal dysfunction
• Hypotension
• Refractory symptoms
• Dependence on intravenous therapies

Patients with advanced heart failure who wish to pursue therapies aimed at prolonging survival should be referred to a specialized heart failure team for assessment of advanced treatment options.

Mechanical Circulatory Support

Selected patients with advanced HFrEF may require mechanical circulatory support.

A left ventricular assist device can support ventricular output in carefully selected patients.

Potential roles include:

• Bridge to transplantation
• Bridge to decision
• Long-term destination therapy in selected patients

These therapies require specialized centers because they involve substantial risks, including bleeding, infection, thrombosis, stroke, and device complications.

Heart Transplantation

Heart transplantation remains an important option for carefully selected patients with end-stage heart failure who meet appropriate criteria.

Potential candidates undergo comprehensive assessment of:

• Cardiac disease severity
• Pulmonary vascular status
• Renal and hepatic function
• Malignancy risk
• Infection risk
• Other comorbidities
• Functional status
• Psychosocial considerations

Because donor organs are limited, transplantation requires careful selection and multidisciplinary evaluation.

Palliative and Supportive Care

Palliative care is not limited to the final days of life.

It can be integrated into advanced heart failure management to address:

• Breathlessness
• Fatigue
• Pain
• Anxiety
• Depression
• Treatment burden
• Advance care planning
• Family support
• Quality of life

In advanced disease, discussions about treatment goals are particularly important.

Patients should understand realistic expectations regarding medications, devices, hospitalization, transplantation, and other interventions.

Prognosis

The prognosis of heart failure varies widely.

Important prognostic factors include:

• Underlying cause
• Ejection fraction
• Functional class
• Age
• Renal function
• Blood pressure
• Natriuretic peptide levels
• Recurrent hospitalization
• Arrhythmias
• Comorbidities
• Response to treatment
• Exercise capacity

A reduced ejection fraction does not determine prognosis by itself.

Some patients experience substantial improvement with treatment, while others progress despite comprehensive management.

Importance of Guideline-Directed Therapy

One of the major advances in heart failure care has been the development of therapies that do more than simply relieve symptoms.

Traditional treatment often focused heavily on reducing congestion and improving hemodynamics.

Modern therapy also targets the biological mechanisms responsible for progressive myocardial injury and remodeling.

For HFrEF, the combination of an ARNI or appropriate renin–angiotensin system inhibitor, evidence-based beta blocker, mineralocorticoid receptor antagonist, and SGLT2 inhibitor forms the central pharmacological strategy.

The practical challenge is ensuring that eligible patients actually receive these therapies at tolerated doses and that treatment is monitored appropriately.

Importance of Multidisciplinary Care

Heart failure management often requires collaboration among:

• Cardiologists
• Internists
• Heart failure specialists
• Nurses
• Pharmacists
• Dietitians
• Physiotherapists
• Primary care clinicians
• Renal specialists
• Electrophysiologists
• Cardiac surgeons
• Palliative care teams

Multidisciplinary care can help coordinate medications, monitoring, education, lifestyle interventions, device assessment, and transitions between hospital and outpatient care.

The ESC also emphasizes multidisciplinary management, rehabilitation, self-care, and coordinated treatment as important components of comprehensive heart failure care.

Exercise and Cardiac Rehabilitation

Exercise intolerance is a major feature of heart failure, but carefully prescribed physical activity can improve functional capacity in appropriate patients.

Exercise programs should be individualized according to:

• Disease severity
• Symptoms
• Hemodynamic stability
• Comorbidities
• Functional capacity

Cardiac rehabilitation can combine exercise training with education, risk-factor modification, medication optimization, and lifestyle support.

Patients with unstable or severely decompensated heart failure require stabilization before undertaking an exercise program.

Dietary Considerations

Nutrition should be individualized.

A balanced diet can help manage:

• Blood pressure
• Diabetes
• Obesity
• Dyslipidemia
• Kidney disease
• Overall cardiovascular risk

Patients with fluid retention may need individualized guidance regarding sodium and fluid intake.

Excessive processed foods often contain large amounts of sodium and can contribute to difficulty controlling fluid balance.

However, extreme dietary restriction is not appropriate for every patient and should be tailored to clinical circumstances.

Medication Adherence

Heart failure medications often need to be taken continuously even when symptoms improve.

Stopping therapy without medical advice can increase the risk of deterioration.

Patients should understand:

• Why each medication is prescribed
• How often it should be taken
• Common adverse effects
• Which symptoms require medical attention
• Which laboratory tests are needed
• What to do if a dose is missed

Medication reconciliation is particularly important after hospitalization because treatment regimens frequently change during acute admissions.

Heart Failure Education

Patient education is a major component of successful long-term management.

Patients should learn to recognize early signs of worsening disease, including:

• Increasing shortness of breath
• New orthopnea
• Increasing ankle swelling
• Rapid weight gain
• Increasing fatigue
• Reduced exercise tolerance
• Persistent cough
• Reduced appetite
• Abdominal swelling

Early recognition can allow treatment adjustments before severe decompensation develops.

Heart Failure in Older Adults

Older adults are particularly vulnerable to heart failure because they commonly have multiple cardiovascular and non-cardiovascular conditions.

Diagnosis may be difficult because symptoms such as fatigue and reduced exercise capacity can be attributed incorrectly to aging.

Older patients may also have:

• Renal impairment
• Frailty
• Cognitive impairment
• Polypharmacy
• Orthostatic hypotension
• Increased sensitivity to medication adverse effects

Treatment should therefore balance evidence-based cardiovascular therapy with individual tolerance, functional status, comorbidity burden, and patient goals.

Heart Failure in Diabetes

Diabetes significantly increases cardiovascular risk and is closely associated with heart failure.

Management should address both conditions.

SGLT2 inhibitors are particularly important because they can provide heart failure and renal benefits in appropriate patients, in addition to their glucose-lowering effects.

Good blood pressure control, lipid management, weight management, and cardiovascular risk reduction remain essential.

Heart Failure and Obesity

Obesity increases the risk of developing heart failure and is particularly associated with HFpEF.

Obesity can increase:

• Blood volume
• Cardiac workload
• Blood pressure
• Inflammatory signaling
• Risk of sleep-disordered breathing
• Risk of diabetes

Weight management should therefore be incorporated into comprehensive cardiovascular care.

Heart Failure and Kidney Disease

Chronic kidney disease frequently coexists with heart failure.

Both diseases can worsen each other.

Reduced renal function can cause:

• Sodium retention
• Fluid accumulation
• Hypertension
• Electrolyte abnormalities
• Difficulty optimizing medications

At the same time, heart failure can worsen kidney perfusion and venous congestion.

Close monitoring is therefore necessary when introducing or titrating therapies that affect renal function or potassium levels.

Important Clinical Distinctions

Several conditions can mimic heart failure symptoms.

Dyspnea may result from:

• Asthma
• COPD
• Pneumonia
• Pulmonary embolism
• Anemia
• Deconditioning
• Anxiety
• Interstitial lung disease

Peripheral edema may result from:

• Chronic venous insufficiency
• Renal disease
• Liver disease
• Medications
• Lymphatic disease

Therefore, heart failure should not be diagnosed solely from one symptom such as leg swelling or shortness of breath.

A structured clinical evaluation is essential.

Key Clinical Approach

When evaluating a patient suspected of having heart failure, a practical sequence is:

First: determine whether the patient is clinically stable.

Second: assess for emergency conditions such as acute coronary syndrome, pulmonary edema, severe arrhythmia, or cardiogenic shock.

Third: obtain a focused history and physical examination.

Fourth: perform appropriate baseline investigations, including ECG, laboratory testing, natriuretic peptides when appropriate, and echocardiography.

Fifth: determine the heart failure phenotype according to ejection fraction and clinical evidence.

Sixth: identify the underlying cause.

Seventh: search for precipitating factors if the patient has acutely deteriorated.

Eighth: initiate appropriate guideline-directed therapy and treatment for congestion.

Ninth: monitor renal function, electrolytes, blood pressure, symptoms, and medication tolerance.

Tenth: arrange appropriate long-term follow-up and consider specialist referral when disease is severe or complex.

Major Takeaway Points

Heart failure is a clinical syndrome caused by structural or functional cardiac abnormalities that impair ventricular filling, ejection, or both.

It can occur with reduced, mildly reduced, or preserved ejection fraction.

The major symptoms include dyspnea, orthopnea, fatigue, reduced exercise capacity, peripheral edema, and fluid-related weight gain.

Common causes include coronary artery disease, hypertension, valvular disease, cardiomyopathy, arrhythmias, myocarditis, and systemic diseases.

Diagnosis requires integration of clinical findings with ECG, laboratory testing, natriuretic peptides when appropriate, chest imaging, and echocardiography.

HFrEF has a particularly strong evidence base for four foundational medication classes: ARNI or renin–angiotensin system inhibition, evidence-based beta blockade, mineralocorticoid receptor antagonism, and SGLT2 inhibition.

HFpEF requires careful treatment of congestion, blood pressure, metabolic disease, atrial fibrillation, coronary disease, obesity, kidney disease, and other contributing conditions, with SGLT2 inhibitors playing an important role in contemporary management.

Successful heart failure care is not limited to prescribing medications. It involves identifying the underlying cause, preventing progression, monitoring for decompensation, improving lifestyle factors, managing comorbidities, and coordinating multidisciplinary care.

Advanced heart failure requires early recognition because selected patients may benefit from specialized therapies such as cardiac devices, mechanical circulatory support, transplantation, or integrated palliative care.