Summary
Congestive heart failure (CHF) is a clinical condition in which the heart is unable to pump enough blood to meet the metabolic needs of the body because of pathological changes in the myocardium. The three main causes of CHF are coronary artery disease (CAD), diabetes mellitus, and hypertension. These conditions cause ventricular dysfunction with low cardiac output, which results in blood congestion and poor systemic perfusion. CHF is classified as either left heart failure (LHF) or right heart failure (RHF), while a combination of both is called biventricular or global CHF. LHF leads to pulmonary edema and consequent dyspnea, while RHF leads to systemic venous congestion that causes symptoms such as pitting edema, jugular venous distension, and hepatomegaly. Biventricular CHF manifests with clinical features of both RHF and LHF, as well as general symptoms such as tachycardia, fatigue, and nocturia. In rare cases, high-output CHF may occur as a result of conditions that increase cardiac output and thereby overwhelm the heart. CHF is diagnosed based on clinical presentation and requires an initial workup to assess the severity of the disease and determine the possible causes. Initial workup includes measurement of brain natriuretic peptide levels, chest x-ray, and an ECG. Management of CHF includes lifestyle modifications and treatment of associated conditions (e.g., hypertension) and comorbidities (e.g., anemia), along with pharmacologic agents that reduce the workload of the heart. Acute heart failure may occur as an exacerbation of CHF (acute decompensated heart failure) or be caused by an acute cardiac condition such as myocardial infarction (see “Acute heart failure”).
Definition
-
Congestive heart failure (CHF)
- A clinical syndrome in which the heart is unable to pump enough blood to meet the metabolic needs of the body
- Characterized by ventricular dysfunction that results in low cardiac output
-
Systolic dysfunction
- CHF with reduced stroke volume, reduced ejection fraction (EF)
- Characterized by increased end-diastolic volume (EDV)
-
Diastolic dysfunction
- CHF with reduced stroke volume, normal/reduced EDV and preserved EF
- Characterized by low myocardial compliance (due to compensatory hypertrophy)
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Right heart failure (RHF)
- CHF due to right ventricular dysfunction
- May result in the development of cor pulmonale in the case of isolated RHF of pulmonary origin
-
Left heart failure (LHF)
- CHF due to left ventricular dysfunction
- Long-standing LHF is the most common cause of RHF. [1]
-
Biventricular (global) CHF
- CHF in which both the left and right ventricle are affected
- Results in the development of both RHF and LHF symptoms
- Chronic compensated CHF: a clinically compensated type of CHF in which the patient has signs of CHF on echocardiography but is asymptomatic or symptomatic and stable [2]
- Acute decompensated CHF: sudden deterioration of CHF or new onset of severe CHF due to an acute cardiac condition (e.g., myocardial infarction)
Epidemiology
- 1–2% of the population in the US (∼ 5.7 million individuals) has CHF. [3]
- The incidence is higher among African Americans and Hispanics . [4]
- Incidence increases with age: ∼ 10% of individuals > 60 years old are affected. [3]
- Systolic heart disease is the most common form of CHF overall.
Epidemiological data refers to the US, unless otherwise specified.
Etiology
Etiology of CHF [3][5] | ||
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Systolic dysfunction (reduced EF) | Diastolic dysfunction (preserved EF) | |
General causes |
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Specific causes |
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Further risk factors |
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The three major causes of heart failure are coronary artery disease, hypertension, and diabetes mellitus. Patients typically have multiple risk factors that contribute to the development of CHF.
Pathophysiology
Cardiac output, which is stroke volume times heart rate, is determined by three factors: preload, afterload, and ventricular contractility.
Underlying mechanism of reduced cardiac output
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Systolic ventricular dysfunction (most common) due to:
- Reduced contractility: damage and loss of myocytes (e.g., following myocardial infarction, CAD, DCM)
- Increased afterload: increase in mean aortic pressure, outflow obstruction (e.g., arterial hypertension, aortic stenosis)
- Increased preload: ventricular volume overload (e.g., backflow into the left ventricle caused by aortic insufficiency)
- Cardiac arrhythmias
- High-output conditions (see “High-output heart failure” below)
-
Diastolic ventricular dysfunction due to:
- Decreased ventricular compliance: increased stiffness or impaired relaxation of the ventricle (e.g., in long-standing arterial hypertension, constrictive pericarditis, pericardial tamponade) → reduced ventricular filling and increased diastolic pressure → decreased cardiac output
- Increased afterload: increase in pulmonary artery pressure (e.g., pulmonary hypertension)
- Increased preload: ventricular volume overload (e.g., tricuspid valve regurgitation, left-to-right shunt)
Consequences of systolic and diastolic dysfunction
- Systolic dysfunction: reduced cardiac output → poor organ perfusion → organ dysfunction (e.g., hypotension, renal dysfunction)
-
Diastolic dysfunction
- Increased left-ventricular volume and pressure → backup of blood into lungs → increased pulmonary capillary pressure → cardiogenic pulmonary edema → orthopnea
- Reduced cardiac output → systemic venous congestion → edema and progressive congestion of internal organs
- Nutmeg liver: the macroscopic appearance of the liver which resembles a nutmeg seed due to ischemia and fatty degeneration from hepatic venous congestion
CHF is characterized by reduced cardiac output that results in venous congestion and poor systemic perfusion.
Compensation mechanisms
The compensation mechanisms are meant to maintain the cardiac output when stroke volume is reduced.
- Increased adrenergic activity: : increase in heart rate, blood pressure, and ventricular contractility
-
Increase of renin-angiotensin-aldosterone system activity (RAAS): activated following decrease in renal perfusion secondary to reduction of stroke volume and cardiac output
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↑ Angiotensin II secretion results in:
- Peripheral vasoconstriction → ↑ systemic blood pressure → ↑ afterload
- Vasoconstriction of the efferent arterioles; → ↓ net renal blood flow and ↑ intraglomerular pressure → maintained GFR
- ↑ Aldosterone secretion → ↑ renal Na+ and H2O resorption → ↑ preload
-
↑ Angiotensin II secretion results in:
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Secretion of brain natriuretic peptide (BNP)
- Definition: ventricular myocyte hormone released in response to increased ventricular filling and stretching
- Mechanism of action: ↑ intracellular smooth muscle cGMP → vasodilation → hypotension and decreased pulmonary capillary wedge pressure
Clinical features
General features of heart failure
- Nocturia [7]
- Fatigue
- Tachycardia, various arrhythmias
- S3/S4 gallop on auscultation
- Pulsus alternans
- Cachexia [8]
Clinical features of left-sided heart failure
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Symptoms of pulmonary congestion
- Dyspnea , orthopnea
- Pulmonary edema
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Paroxysmal nocturnal dyspnea
- Nocturnal bouts of coughing and acute shortness of breath
- Caused by reabsorption of peripheral edema at night → increased venous return
-
Cardiac asthma
- Increased pressure in the bronchial arteries → airway compression and bronchospasm
- Symptoms mimic asthma, with shortness of breath, wheezing, and coughing. [9]
-
Physical examination findings [10]
- Bilateral basilar rales may be audible on auscultation.
- Laterally displaced apical heart beat (precordial palpation beyond the midclavicular line)
- Coolness and palor of lower extremities
Clinical features of right-sided heart failure
-
Symptoms of fluid retention and increased CVP
- Peripheral pitting edema: as a result of fluid transudation due to increased venous pressure
- Hepatic venous congestion symptoms
- Other symptoms of organ congestion (e.g., nausea, loss of appetite in congestive gastropathy)
-
Physical examination findings
- Jugular venous distention: visible swelling of the jugular veins due to an increase in CVP and venous congestion
- Kussmaul sign
- Hepatosplenomegaly: may result in cardiac cirrhosis and ascites
- Hepatojugular reflux: jugular venous congestion induced by exerting manual pressure over the patient's liver → ↑ right heart volume overload → inability of the right heart to pump additional blood → visible jugular venous distention that persists for several seconds
In clinical practice, biventricular heart failure with features of left and right heart failure is more likely than isolated failure of one ventricle.
Subtypes and variants
High-output heart failure
- Definition: heart failure secondary to conditions associated with a high-output state, in which cardiac output is elevated to meet the peripheral tissue oxygen demands
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Etiology: conditions that lead to an increased cardiac demand (high-output state) [11]
- Physiological causes
- Other causes
- Anemia
- Systemic arteriovenous fistulas (e.g., Paget disease of bone)
- Hyperthyroidism
- Wet beriberi (vitamin B1 deficiency)
- Sepsis
- Multiple myeloma
- Glomerulonephritis
- Polycythemia vera
- Carcinoid heart disease [12]
-
Clinical features
-
Symptoms of low-output CHF [13]
- Dyspnea, tachypnea
- Tachycardia
- Low blood pressure
- Jugular distention with an audible hum over the internal jugular vein
- Pulsatile tinnitus
- Bounding peripheral pulses
- Laterally displaced apical heart beat
- Midsystolic murmur, S3 gallop
-
Symptoms of low-output CHF [13]
-
Diagnostics
- Primarily a clinical diagnosis
- X-ray and echocardiography: cardiomegaly
-
Therapy
-
Heart failure management
- Symptom relief
- Hemodynamic stabilization
- Treatment of the underlying condition
-
Heart failure management
Stages
NYHA functional classification [14]
The NYHA (New York Heart Association) functional classification system is used to assess the patient's functional capacities (i.e., limitations of physical activity and symptoms) and has prognostic value.
NYHA class | Characteristics |
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Class I |
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Class II |
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Class III |
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Class IV |
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American Heart Association (AHA) classification (2013) [14]
The AHA classification system classifies patients according to their stage of disease. It takes objective findings (patient history, diagnostic findings) as well as symptoms of CHF into account.
Stages | Objective assessment | Corresponding NYHA functional class |
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Stage A |
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Stage B |
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Stage C |
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Stage D |
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Diagnostics
Diagnostic approach [15]
- Medical history, including preexisting conditions and history of alcohol and recreational/prescribed drug use
- Initial evaluation involves a range of routine laboratory tests and a test for BNP level, ECG, and chest x-ray.
- Echocardiography is the gold standard for the diagnosis of CHF.
- Other procedures (e.g., exercise testing, angiography) may be required for further investigation.
Initial evaluation [15]
Laboratory analysis
-
Elevated BNP and NT-pro BNP
- NT-pro BNP is a precursor of BNP that is used as a diagnostic marker of heart failure.
- High levels of BNP in patients with classic symptoms of CHF confirm the diagnosis (high predictive index). [16]
BNP and NT-pro BNP levels in CHF | ||
---|---|---|
Markers | CHF unlikely | CHF likely |
BNP (ng/L) [17] | < 100 | > 400 |
NT-pro BNP (ng/L) [10] | < 300 | > 450 |
- Elevated atrial natriuretic peptide (ANP): Elevated levels of mid-regional pro-atrial natriuretic peptide (MR-proANP) have a good diagnostic value in suspected CHF. [18][19]
- Complete blood count: may show anemia
- Serum electrolyte levels: Hyponatremia indicates a poor prognosis.
- Kidney function tests: ↑ creatinine, ↓ sodium
- Urine analysis: to rule out concurrent renal impairment
- Fasting glucose: to screen for diabetes mellitus, which is a common comorbidity
- Fasting lipid profile: to detect dyslipidemia associated with a higher cardiovascular risk
Electrocardiogram (ECG)
ECG abnormalities in CHF are common, but are mostly nonspecific and nondiagnostic. [10]
-
Signs of left ventricular hypertrophy [20]
- ↑ QRS voltage (in the left chest leads and limb leads I and aVL): positive Sokolow-Lyon index
- ↑ QRS duration (incomplete or complete left bundle branch block)
- Left axis deviation
- ST-T abnormalities (e.g., ST-depression)
- P wave abnormalities (e.g., P-mitrale, biphasic P wave)
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Assessment of prior or concurrent heart conditions
- Previous or acute MI (see “ECG changes in STEMI”)
- Arrhythmias (e.g., atrial fibrillation, ventricular arrhythmias, sinus tachycardia or bradycardia, AV block)
- Signs of pericardial effusion and pericardial tamponade: low voltage ECG
Chest x-ray
Useful diagnostic tool to evaluate a patient with dyspnea and differentiate CHF from pulmonary disease
-
Signs of cardiomegaly
- Cardiothoracic width ratio > 0.5
- Boot-shaped heart on PA view (due to right ventricular enlargement)
- Pulmonary congestion: See “X-ray findings in pulmonary congestion” for more information.
Transthoracic echocardiogram
Gold standard for evaluating patients with heart failure
-
Assess ventricular function and hemodynamics
- Atrial and ventricular size
- Interventricular septum thickness: > 11 mm indicates cardiac hypertrophy.
-
Systolic function: left ventricular ejection fraction [21]
- Normal EF: 50–70%
- Borderline EF: 41–49%
- Reduced EF: ≤ 40%
- Diastolic function (diastolic filling, ventricle dilation)
-
Investigate etiology
- Valvular heart disease
- Wall motion abnormalities (indicate prior or acute MI)
- Right ventricular strain
- Tissue Doppler: ↑ PCWP in left-sided heart failure
Other tests
- Cardiac stress test (exercise tolerance test): to assess the functional impairment due to CHF or other conditions (particularly CHD)
- Radionuclide ventriculography : indicated to assess left ventricular volume and ejection fraction (LVEF) [22]
-
Cardiac MRI
- Particularly useful for assessing cardiac morphology and function [23]
- Cardiac size and volumes, wall thickness, valvular defects, wall motion abnormalities
- Coronary angiography (left heart catheterization): indicated to detect/confirm CHD and possible percutaneous coronary intervention
-
Right heart catheterization [24]
- If pulmonary hypertension is suspected, to assess the severity of systolic dysfunction, and/or to differentiate between types of shock
- SvO2 will be low in decompensated heart failure.
- Endomyocardial biopsy: may be performed if a specific diagnosis is suspected in patients with rapidly progressive clinical CHF or in case the results would alter the management of the patient (e.g., in amyloidosis) [25]
Pathology
Sputum analysis in patients with pulmonary edema may show heart failure cells (hemosiderin-containing cells).
Treatment
General measures [15]
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Lifestyle modifications
- Salt restriction (2–3 g/day) in symptomatic patients
- Fluid restriction in patients with edema and/or hyponatremia
- Weight loss and exercise
- Cessation of smoking and alcohol consumption
- Immunization: pneumococcal vaccine and seasonal influenza vaccine
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Patient education
- Self-monitoring and symptom recognition
- Daily weight check: A weight gain > 2 kg within 3 days requires a doctor consult.
- Monitoring of potential medication side effects (e.g., hypotension caused by ACE inhibitors, hyperkalemia caused by aldosterone-antagonists, sensitivity to sunlight caused by amiodarone)
- Travel restrictions [26][27]
- Include most recent medical record when traveling
- Advise against traveling to destinations with limited access to or inadequate health care
- Patients with acute heart failure should restrain from traveling
- Treatment of underlying conditions and contributing comorbidities
Pharmacologic treatment algorithm [28][29]
Drug | NYHA stages | Indications | Contraindications and important side effects | Benefits | |||
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I | II | III | IV | ||||
First-line drugs | |||||||
Diuretics | (✓) | (✓) | ✓ | ✓ |
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|
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ACE inhibitors | ✓ | ✓ | ✓ | ✓ |
|
|
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Beta blockers | (✓) | ✓ | ✓ | ✓ |
|
| |
Aldosterone antagonists | (✓) | ✓ | ✓ |
|
| ||
Second-line drugs | |||||||
Ivabradine | (✓) | (✓) | (✓) |
|
|
| |
Hydralazine plus nitrate [30] | (✓) | (✓) |
|
|
| ||
Digoxin [15] | (✓) | (✓) | (✓) |
|
|
| |
Angiotensin receptor-neprilysin inhibitor | (✓) | (✓) | (✓) | (✓) |
|
|
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Nesiritide (BNP derivative) |
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| |||||
(✓): see “Indications” column for detailed information |
Drugs that improve prognosis are beta blockers, ACE inhibitors, and aldosterone antagonists.
Drugs that improve symptoms are diuretics and digoxin (significantly reduce the number of hospitalizations).
Conducting regular blood tests to assess electrolyte levels (potassium and sodium) is mandatory if the patient is on diuretics.
Contraindicated drugs [32][33]
-
NSAIDs
- Worsen renal perfusion
- Reduce the effect of diuretics
- May trigger acute cardiac decompensation
- See “Nonsteroidal anti-inflammatory drugs.”
-
Inhalation anesthetics
- Induce myocardial depression and peripheral vasodilation
- Decrease sympathetic activity
-
Calcium channel blockers (verapamil and diltiazem)
- Negative inotropic effect
- Worsen symptoms and prognosis
-
Thiazolidinediones
- Promote the progression of CHF (↑ fluid retention and edema)
- Increase the hospitalization rate
- Moxonidine: increases mortality in CHF with reduced ejection fraction (systolic dysfunction)
- Antidepressants (citalopram): causes a dose-dependent QT prolongation
Avoid the concomitant use of calcium channel blockers with beta blockers.
Invasive procedures
-
Implantable cardiac defibrillator (ICD): an implanted device that prevents sudden cardiac death by delivering electrical impulses to convert heart rhythm back into sinus rhythm
- Primary prophylaxis indications [34]
- Patients with ischemic heart disease and EF ≤ 30%
- Heart failure NYHA class II–IV with EF ≤ 35%
- Increased risk of life-threatening cardiac arrhythmias
- Secondary prophylaxis indications
- History of sudden cardiac arrest
- Ventricular flutter or ventricular fibrillation [35]
- Primary prophylaxis indications [34]
-
Cardiac resynchronization therapy (biventricular pacemaker): a three-chamber cardiac pacemakers used in symptomatic chronic heart failure to improve cardiac function
- Indications [36]
- Heart failure NYHA class II–IV with EF ≤ 35% [37]
- Dilated cardiomyopathy
- Left bundle branch block with QRS > 150 ms [38]
- Can be combined with an ICD
- Indications [36]
- Coronary revascularization: may be used with PCTA or bypass surgery if CAD is present
- Valvular surgery: if valvular heart defects are present
-
Ventricular assist devices
- May be implanted to support ventricular function
- May be indicated for temporary or long-term support (e.g., to bridge time until transplantation) of decompensated CHF
-
Cardiac transplantation
- Patients with end-stage CHF (NYHA class IV)
- EF < 20%
- No other viable treatment options
Complications
- Acute decompensated heart failure (see “Acute heart failure”)
- Cardiorenal syndrome
- Cardiac arrhythmias
- Central sleep apnea
- Cardiogenic shock
- Stroke: due to increased risk of arterial thromboembolisms (especially with concurrent atrial fibrillation)
- Chronic kidney disease
- Cardiac cirrhosis (congestive hepatopathy): cirrhosis due to chronic hepatic vein congestion in patients with right‑sided heart failure
- Venous stasis, leg ulcers
We list the most important complications. The selection is not exhaustive.
Cardiorenal syndrome
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Definition
- A complex syndrome in which renal function progressively declines as a result of severe cardiac dysfunction [39]
- Occurs in ∼ 30% of cases of ADHF [40]
-
Pathophysiology
- Systolic dysfunction → reduced cardiac output → renal hypoperfusion → prerenal kidney failure
- Diastolic dysfunction → systemic venous congestion → renal venous congestion → decreased transglomerular pressure gradient → ↓ GFR → worsening kidney function
- RAAS activation → salt and fluid retention → hypertension → hypertensive nephropathy
- Diagnosis: ↓ GFR, ↑ creatinine that cannot be explained by underlying kidney disease [41]
- Treatment: heart failure and renal failure management (see “Acute renal injury”)
- Prognosis: : CHF with reduced GFR and high creatinine levels (> 3 mg/dL) is associated with a poor prognosis. [41][42]
Prognosis
The prognosis depends on the patient, type and severity of heart disease, medication regimens, and lifestyle changes. The prognosis for patients with preserved EF is similar to or better than for patients with decreased EF. Risk stratification scales may be used to evaluate the prognosis (e.g., CHARM and CORONA risk scores).
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Factors associated with worse prognosis [43]
- Elevated BNP
- Hyponatremia
- Systolic BP < 120 mm Hg
- Diabetes
- Anemia
- Weight loss or underweight
- S3 heart sound
- Implantable cardioverter-defibrillator use
- Frequent hospitalizations due to CHF
-
1-year survival according to NYHA stage
- Stage I: ∼ 95%
- Stage II: ∼ 85%
- Stage III: ∼ 85%
- Stage IV: ∼ 35%
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