TheInfoList

Heart failure (HF), also known as congestive heart failure (CHF) and (congestive) cardiac failure (CCF), is a set of manifestations caused by the failure of the
heart The heart is a cardiac muscle, muscular Organ (biology), organ in most animals, which pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste ...

's function as a pump supporting the blood flow through the body; its
signs and symptoms Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showi ...
result from a structural and/or functional abnormality of the heart, that disrupts its filling with blood or its ejecting of it during each heart beat. Signs and symptoms of heart failure commonly include
shortness of breath Shortness of breath (SOB), also known as dyspnea (BrE British English (BrE) is the standard dialect A standard language (also standard variety, standard dialect, and standard) is a language variety that has undergone substantial codificat ...
, excessive tiredness, and leg swelling. The shortness of breath is usually worse with
exercise Exercise is any bodily activity that enhances or maintains physical fitness Physical fitness is a state of health Health is a state of physical, mental and social well-being Well-being, also known as ''wellness'', ''prudential value ...
or while
lying down "Lying Down" is a song recorded by Canadian singer Celine Dion for her twelfth English-language studio album, ''Courage (Celine Dion album), Courage'' (2019). It was written by David Guetta, Giorgio Tuinfort and Sia (musician), Sia, and produced by ...
, and may wake the person at night. A limited ability to exercise is also a common feature.
Chest pain Chest pain is pain or discomfort in the chest, typically the front of the chest. It may be described as sharp, dull, pressure, heaviness or squeezing. Associated symptoms may include pain in the shoulder, arm, upper abdomen, or jaw, along with nau ...
, including
angina Angina, also known as angina pectoris, is chest pain Chest pain is pain or discomfort in the chest, typically the front of the chest. It may be described as sharp, dull, pressure, heaviness or squeezing. Associated symptoms may include pain in ...

, does not typically occur due to heart failure. Common causes of heart failure include
coronary artery disease Coronary artery disease (CAD), also called coronary heart disease (CHD), ischemic heart disease (IHD), or simply heart disease, involves the reduction of blood flow to the heart muscle Cardiac muscle (also called heart muscle or myocardium) is ...
, including a previous
myocardial infarction A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow Hemodynamics American and British English spelling differences#ae and oe, or haemodynamics are the Fluid dynamics, dynamics of blood flow. The circulatory sy ...

(heart attack),
high blood pressure Hypertension (HTN or HT), also known as high blood pressure (HBP), is a long-term Long-Term Capital Management L.P. (LTCM) was a hedge fund''A financial History of the United States Volume II: 1970–2001'', Jerry W. Markham, Chapter 5: "Bank ...

,
atrial fibrillation Atrial fibrillation (AF or A-fib) is an abnormal heart rhythm (arrhythmia) characterized by the rapid and irregular beating of the atrial chambers of the heart. It often begins as short periods of abnormal beating, which become longer or cont ...

,
valvular heart disease Valvular heart disease is any cardiovascular disease Cardiovascular disease (CVD) is a class of diseases that involve the heart The heart is a muscle, muscular Organ (anatomy), organ in most animals, which pumps blood through the blood ...
, excess alcohol use,
infection An infection is the invasion of an organism's body by , their multiplication, and the reaction of tissues to the infectious agents and the s they produce. An infectious disease, also known as a transmissible disease or communicable disease, i ...

, and
cardiomyopathy Cardiomyopathy is a group of diseases that affect the heart muscle Cardiac muscle (also called heart muscle or myocardium) is one of three types of vertebrate Vertebrates () comprise all species of animal Animals (also called Metaz ...
of an unknown cause. These cause heart failure by changing either the structure or the function of the heart. The two types of left ventricular heart failureheart failure with reduced ejection fraction (HFrEF), and
heart failure with preserved ejection fraction Heart failure with preserved ejection fraction (HFpEF) is a form of heart failure Heart failure (HF), also known as congestive heart failure (CHF), (congestive) cardiac failure (CCF), and decompensatio cordis, is when the heart The heart ...
(HFpEF) – are based on whether the ability of the
left ventricle A ventricle is one of two large chambers toward the bottom of the heart The heart is a muscle, muscular Organ (anatomy), organ in most animals, which pumps blood through the blood vessels of the circulatory system. The pumped blood carries ...
to contract, or to relax, is affected. The severity of the heart failure is graded by the severity of symptoms with exercise. Heart failure is not the same as
heart attack A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow Hemodynamics American and British English spelling differences#ae and oe, or haemodynamics are the Fluid dynamics, dynamics of blood flow. The circulatory sys ...

(in which part of the heart muscle dies due to a clot in the arteries supplying the heart) or
cardiac arrest Cardiac arrest is a sudden loss of circulatory system, blood flow resulting from the failure of the heart to pump effectively. Signs include unconsciousness, loss of consciousness and respiratory arrest, abnormal or absent breathing. Some indivi ...
(in which blood flow stops altogether due to failure of the heart to pump effectively). Other diseases that may have symptoms similar to heart failure include
obesity Obesity is a medical condition A disease is a particular abnormal condition that negatively affects the structure or function (biology), function of all or part of an organism, and that is not due to any immediate external injury. ...

,
kidney failure Kidney failure, also known as end-stage kidney disease, is a medical condition in which the kidneys are functioning at less than 15% of normal levels. Kidney failure is classified as either acute kidney failure, which develops rapidly and may res ...
, liver problems,
anemia Anemia (American and British English spelling differences#ae and oe, also spelled anaemia) is a decrease in the total amount of red blood cells (RBCs) or hemoglobin in the blood, or a lowered ability of the blood to carry oxygen. When anemia c ...

, and
thyroid disease Thyroid disease is a medical condition that affects the function of the thyroid gland. The thyroid gland is located at the front of the neck and produces thyroid hormones that travel through the blood to help regulate many other organs, meaning t ...
. Diagnosis is based on symptoms, physical findings, and
echocardiography An echocardiography, echocardiogram, cardiac echo or simply an echo, is an of the . It is a type of of the heart, using standard ultrasound or . Echocardiography has become routinely used in the diagnosis, management, and follow-up of patients ...
.
Blood test A blood test is a laboratory A laboratory (; ; colloquially lab) is a facility that provides controlled conditions in which or technological research, s, and may be performed. Laboratory services are provided in a variety of settings: ...

s,
electrocardiography Electrocardiography is the process of producing an electrocardiogram (ECG or EKG). It is an of the which is a graph of versus time of the electrical activity of the heart using s placed on the skin. These electrodes detect the small electri ...
, and
chest radiography A chest radiograph, called a chest X-ray (CXR), or chest film, is a Projectional radiography, projection radiograph of the chest used to diagnose conditions affecting the chest, its contents, and nearby structures. Chest radiographs are the most ...
may be useful to determine the underlying cause. Treatment depends on the severity and cause of the disease. In people with chronic stable mild heart failure, treatment commonly consists of lifestyle modifications such as stopping smoking,
physical exercise Exercise is any bodily activity that enhances or maintains physical fitness Physical fitness is a state of health Health is a state of physical, mental and social well-being Well-being, also known as ''wellness'', ''prudential valu ...
, and dietary changes, as well as medications. In those with heart failure due to left ventricular dysfunction,
angiotensin converting enzyme inhibitor Angiotensin-converting-enzyme inhibitors (ACE inhibitors) are a class of medication A medication (also referred to as medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to medical diagnosis, diagnose, cure, therapy ...
s, angiotensin receptor blockers, or valsartan/sacubitril along with
beta blockers Beta blockers (beta-blockers, β-blockers, etc.) are a class of medications that are predominantly used to manage cardiac arrhythmia, abnormal heart rhythms, and to protect the heart from a second heart attack (myocardial infarction) after a firs ...
are recommended. For those with severe disease, aldosterone antagonists, or
hydralazine Hydralazine, sold under the brand name Apresoline among others, is a medication used to treat high blood pressure Hypertension (HTN or HT), also known as high blood pressure (HBP), is a long-term Disease, medical condition in which the blood ...

with a
nitrate Nitrate is a polyatomic ion A polyatomic ion, also known as a molecular ion, is a covalently bonded A covalent bond is a chemical bond A chemical bond is a lasting attraction between atoms, ions or molecules that enables the format ...
may be used.
Diuretics A diuretic () is any substance that promotes diuresis, the increased production of urine Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. U ...
are useful for preventing fluid retention and the resulting shortness of breath. Sometimes, depending on the cause, an implanted device such as a
pacemaker A cardiac pacemaker (or artificial pacemaker, so as not to be confused with the natural pacemaker of the heart The heart is a muscle, muscular Organ (anatomy), organ in most animals, which pumps blood through the blood vessels of the cir ...
or an
implantable cardiac defibrillator An implantable cardioverter-defibrillator (ICD) or automated implantable cardioverter defibrillator (AICD) is a device implantable inside the body, able to perform cardioversion Cardioversion is a medical procedure by which an abnormally fa ...
may be recommended. In some moderate or severe cases,
cardiac resynchronization therapy Cardiac resynchronisation therapy (CRT or CRT-P) is the insertion of electrode An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit (e.g. a semiconductor A semiconductor material has an Electric ...
(CRT) or
cardiac contractility modulation Cardiac Contractility Modulation is a therapy A therapy or medical treatment (often abbreviated tx, Tx, or Tx) is the attempted remediation of a health Health is a state of physical, mental and social well-being Well-being, also known as ...
may be of benefit. A
ventricular assist device A ventricular assist device (VAD) is an electromechanics, electromechanical device for assisting cardiac circulation, which is used either to partially or to completely replace the function of a failing heart. The function of VADs is different fro ...

(for the left, right, or both ventricles), or occasionally a
heart transplant A heart transplant, or a cardiac transplant, is a surgical transplant procedure performed on patients with end-stage heart failure Heart failure (HF), also known as congestive heart failure (CHF), (congestive) cardiac failure (CCF), and decomp ...
may be recommended in those with severe disease that persists despite all other measures. Heart failure is a common, costly, and potentially fatal condition, and it is the leading cause of both hospitalization and readmission amongst older adults. In 2015, it affected about 40 million people globally. Overall around 2% of adults have heart failure and in those over the age of 65, this increases to 6–10%. Also at Rates are predicted to increase. The risk of death is about 35% the first year after diagnosis, while by the second year the risk of death is less than 10% for those who remain alive. This degree of risk of death is similar to some cancers. In the United Kingdom, the disease is the reason for 5% of emergency hospital admissions. Heart failure has been known since ancient times, with the
Ebers papyrus The Ebers Papyrus, also known as Papyrus Ebers, is an Egyptian medical papyri, Egyptian medical papyrus of herbal knowledge dating to circa 1550 BC. Among the oldest and most important medical papyri of ancient Egypt, it was purchased at Luxor i ...
commenting on it around 1550 BCE.

Classification

Heart failure is not a disease but a
syndrome A syndrome is a set of medical signs and symptoms Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, rais ...
, a cluster of
signs and symptoms Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showi ...
caused by the impairment of the heart's function as a pump to support the
circulatory system The circulatory system, also called the cardiovascular system or the vascular system, is an organ system An organ system is a biological system A biological system is a complex network Network and networking may refer to: Arts, entertai ...
, at rest or during exercise. It develops when the heart fails to properly fill up with blood during
diastole Diastole ( ) is the part of the cardiac cycle and adjacent deflections. Re the cardiac cycle, ''atrial systole'' begins at the P wave; ''ventricular systole'' begins at the Q deflection of the QRS complex. The cardiac cycle is the performance ...
leading to an increase in intracardiac pressures or in ejecting it during
systole The systole ( ) is the part of the cardiac cycle The cardiac cycle is the performance of the human heart The heart is a cardiac muscle, muscular Organ (biology), organ in most animals, which pumps blood through the blood vessels of ...
, thereby reducing cardiac output to the rest of the body. Filling dysfunction and high intracardiac pressure may result in the buildup of fluid in the veins and tissues. This manifests as water retention and swelling due to the buildup of liquid (
edema Edema, also spelled oedema, and also known as fluid retention, dropsy, hydropsy and swelling, is the build-up of fluid in the body's tissue Tissue may refer to: Biology * Tissue (biology), an ensemble of similar cells that together carry out a ...

), collectively referred to as congestion. Impaired ejection can cause inadequate perfusion of the body tissues with blood leading to
ischemia Ischemia or ischaemia is a restriction in blood Blood is a body fluid in humans and other animals that delivers necessary substances such as nutrients and oxygen to the Cell (biology), cells and transports metabolic waste products away fr ...
.

Signs and symptoms

Heart failure is a
pathophysiological Pathophysiology ( physiopathology) – a convergence of pathology Pathology is the study of the causes and effects of disease A disease is a particular abnormal condition that negatively affects the structure or function of all ...
state in which
cardiac output Cardiac output (CO), also known as heart output denoted by the symbols Q, or \dot Q_ , is a term used in cardiac physiologyCardiac physiology or heart function is the study of healthy, unimpaired function of the heart: involving blood flow; Ca ...
is insufficient to meet the needs of the body and lungs. The term "congestive heart failure" is often used, as one of the common symptoms is , or build-up of fluid in a person's tissues and veins in the lungs or other parts of the body. Specifically, congestion takes the form of water retention and swelling (
edema Edema, also spelled oedema, and also known as fluid retention, dropsy, hydropsy and swelling, is the build-up of fluid in the body's tissue Tissue may refer to: Biology * Tissue (biology), an ensemble of similar cells that together carry out a ...

), both as
peripheral edema Peripheral edema is edema (accumulation of fluid causing swelling) in tissues perfused by the peripheral vascular system, usually in the lower Limb (anatomy), limbs. In the most dependent parts of the body (those hanging distally), it may be called ...
(causing swollen limbs and feet) and as
pulmonary edema Pulmonary edema (PE), also known as pulmonary congestion, is liquid accumulation in the tissue Tissue may refer to: Biology * Tissue (biology), an ensemble of similar cells that together carry out a specific function * ''Triphosa haesitata'', a ...

(causing breathing difficulty), as well as
ascites Ascites is the abnormal build-up of fluid in the abdomen. Technically, it is more than 25 ml of fluid in the peritoneal cavity, although volumes greater than one liter may occur. Symptoms may include increased abdominal size, increased weight, abd ...
(swollen abdomen). Heart failure symptoms are traditionally divided into left- and right-sided, recognizing that the left and right ventricles of the heart supply different portions of the circulation, but people commonly have both sets of signs and symptoms.

Left-sided failure

The left side of the heart receives oxygen-rich blood from the lungs and pumps it forward to the
systemic circulation The circulatory system, also called the cardiovascular system or the vascular system, is an organ system that permits blood to circulate and transport nutrients (such as amino acids and electrolytes), oxygen, carbon dioxide, hormones, and bloo ...
(the rest of the body except for the
pulmonary circulation The mammalian heart is divided between the systemic and the pulmonary circulation, generally agreed upon as left and right sided circuits. The right circuit is the portion of the circulatory system The circulatory system, also called the ca ...
). Failure of the left side of the heart causes blood to back up (be congested) into the lungs, causing respiratory symptoms and fatigue due to an insufficient supply of oxygenated blood. Common respiratory signs are increased rate of breathing and increased ''work'' of breathing (nonspecific signs of respiratory distress).
Rales Crackles are the clicking, rattling, or crackling noises that may be made by one or both lung The lungs are the primary organs of the respiratory system in human Humans (''Homo sapiens'') are the most populous and widespread specie ...
or crackles, heard initially in the lung bases, and when severe, throughout the lung fields suggest the development of
pulmonary edema Pulmonary edema (PE), also known as pulmonary congestion, is liquid accumulation in the tissue Tissue may refer to: Biology * Tissue (biology), an ensemble of similar cells that together carry out a specific function * ''Triphosa haesitata'', a ...

(fluid in the
alveoli Alveolus (pl. alveoli, adj. alveolar) is a general anatomical term for a concave cavity or pit. Alveolus may refer to: In anatomy and zoology in general * Pulmonary alveolus, an air sac in the lungs ** Alveolar cell or pneumocyte ** Alveolar duct ...
).
Cyanosis Cyanosis is the change of body Tissue (biology), tissue color to a bluish-purple hue as a result of having decreased amounts of oxygen bound to the hemoglobin in the Red blood cell, red blood cells of the capillary bed. Body tissues that reflect ...
, which suggests severe low blood oxygen, is a late sign of extremely severe pulmonary edema. Additional signs indicating left ventricular failure include a laterally displaced (which occurs if the heart is enlarged) and a
gallop rhythm A gallop rhythm refers to a (usually abnormal) rhythm of the heart on auscultation:''For the ancient monasterial worker, see Auscultare'' Auscultation (based on the Latin verb ''auscultare'' "to listen") is listening to the internal sounds of th ...
(additional heart sounds) may be heard as a marker of increased blood flow or increased intracardiac pressure.
Heart murmur Heart murmurs are heart sounds Heart sounds are the noises generated by the beating heart The heart is a muscle, muscular Organ (anatomy), organ in most animals, which pumps blood through the blood vessels of the circulatory system. ...
s may indicate the presence of valvular heart disease, either as a cause (e.g.
aortic stenosis Aortic stenosis (AS or AoS) is the narrowing of the exit of the left ventricle A ventricle is one of two large chambers toward the bottom of the heart The heart is a muscle, muscular Organ (anatomy), organ in most animals, which pumps ...

) or as a result (e.g.
mitral regurgitation Mitral regurgitation (MR), also known as mitral insufficiency, or mitral incompetence is a form of valvular heart disease in which the mitral valve is insufficient and does not close properly when the heart pumps out blood. Section: Valvular Hear ...

) of heart failure. ''Backward'' failure of the left ventricle causes congestion of the lungs' blood vessels, so the symptoms are predominantly respiratory in nature. Backward failure can be subdivided into the failure of the left atrium, the left ventricle, or both within the left circuit. The person will have
dyspnea Shortness of breath (SOB), also known as dyspnea (BrE British English (BrE) is the standard dialect A standard language (also standard variety, standard dialect, and standard) is a language variety that has undergone substantial codificat ...
(shortness of breath) on exertion and in severe cases, dyspnea at rest. Increasing breathlessness on lying flat, called
orthopnea Orthopnea or orthopnoea is shortness of breath Shortness of breath (SOB), also known as dyspnea (BrE: dyspnoea) is a feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breath ...
, occurs. It is often measured in the number of pillows required to lie comfortably, and in orthopnea, the person may resort to sleeping while sitting up. Another symptom of heart failure is
paroxysmal nocturnal dyspnea Paroxysmal nocturnal dyspnea or paroxysmal nocturnal dyspnoea (PND) is an attack of severe shortness of breath Shortness of breath (SOB), also known as dyspnea (BrE: dyspnoea) is a feeling of not being able to breathe well enough. The American Th ...
: a sudden night-time attack of severe breathlessness, usually several hours after going to sleep. Easy fatigability and exercise intolerance are also common complaints related to respiratory compromise. " Cardiac asthma" or
wheezing A wheeze is a continuous, coarse, whistling sound produced in the respiratory airways during breathing. For wheezes to occur, some part of the respiratory tree must be narrowed or obstructed (for example narrowing of the lower respiratory tract ...
may occur.Compromise of left ventricular ''forward'' function may result in symptoms of poor systemic circulation such as
dizziness Dizziness is an imprecise term that can refer to a sense of disorientation in space, vertigo Vertigo is a condition where a person has the sensation of moving or of surrounding objects moving when they are not. Often it feels like a spinnin ...

,
confusion In medicine Medicine is the science Science () is a systematic enterprise that builds and organizes knowledge Knowledge is a familiarity, awareness, or understanding of someone or something, such as facts ( descriptive knowledg ...

, and cool extremities at rest.

Right-sided failure

Right-sided heart failure is often caused by
pulmonary heart disease Pulmonary heart disease, also known as cor pulmonale, is the enlargement and failure of the right ventricle of the heart as a response to increased vascular resistance (such as from pulmonic stenosis) or high blood pressure in the lungs. Chro ...
(cor pulmonale), which is typically caused by difficulties of the
pulmonary circulation The mammalian heart is divided between the systemic and the pulmonary circulation, generally agreed upon as left and right sided circuits. The right circuit is the portion of the circulatory system The circulatory system, also called the ca ...
, such as
pulmonary hypertension Pulmonary hypertension (PH or PHTN) is a condition of increased blood pressure within the arteries of the lungs. Symptoms include shortness of breath, syncope, tiredness, chest pain, pedal edema, swelling of the legs, and a fast heartbeat. The ...
or pulmonic stenosis.Physical examination may reveal pitting peripheral edema, ascites, liver enlargement, and spleen enlargement.
Jugular venous pressure and marked jugular venous distention. External jugular vein marked by an arrow; however, JVP is not measured by looking at the external jugular vein even but is instead measured by pulsations of the skin from the internal jugular vein, which is not ...
is frequently assessed as a marker of fluid status, which can be accentuated by eliciting hepatojugular reflux. If the right ventricular pressure is increased, a parasternal heave may be present, signifying the compensatory increase in contraction strength. ''Backward'' failure of the right ventricle leads to congestion of systemic capillaries. This generates excess fluid accumulation in the body. This causes swelling under the skin (termed
peripheral edema Peripheral edema is edema (accumulation of fluid causing swelling) in tissues perfused by the peripheral vascular system, usually in the lower Limb (anatomy), limbs. In the most dependent parts of the body (those hanging distally), it may be called ...
or
anasarca Anasarca is a severe and generalized form of edema Edema, also spelt oedema, and also known as fluid retention, dropsy, hydropsy and swelling, is the build-up of fluid in the body's Tissue (biology), tissue. Most commonly, the legs or arms are a ...
) and usually affects the dependent parts of the body first (causing foot and ankle swelling in people who are standing up, and edema in people who are predominantly lying down).
Nocturia Nocturia is defined by the International Continence Society (ICS) as “the complaint that the individual has to wake at night one or more times for voiding (''i.e. to urinate'').” The term is derived from Latin Latin (, or , ) is a classical ...
(frequent night-time urination) may occur when fluid from the legs is returned to the bloodstream while lying down at night. In progressively severe cases, ascites (fluid accumulation in the abdominal cavity causing swelling) and liver enlargement may develop. Significant liver congestion may result in impaired liver function ( congestive hepatopathy), and jaundice and even
coagulopathy Coagulopathy (also called a bleeding disorder) is a condition in which the blood's ability to coagulate Coagulation, also known as clotting, is the process by which blood changes from a liquid to a gel, forming a thrombus, blood clot. It potenti ...
(problems of decreased or increased blood clotting) may occur.

Biventricular failure

Dullness of the lung fields to finger percussion and reduced breath sounds at the bases of the lung may suggest the development of a
pleural effusion A pleural effusion is accumulation of excessive fluid in the pleural space, the potential space that surrounds each lung. Under normal conditions, pleural fluid is secreted by the parietal pleural capillaries at a rate of 0.01 millilitre per kilo ...

(fluid collection between the lung and the chest wall). Though it can occur in isolated left- or right-sided heart failure, it is more common in biventricular failure because pleural veins drain into both the systemic and pulmonary venous systems. When unilateral, effusions are often right-sided. If a person with a failure of one ventricle lives long enough, it will tend to progress to failure of both ventricles. For example, left ventricular failure allows pulmonary edema and pulmonary hypertension to occur, which increase stress on the right ventricle. Right ventricular failure is not as deleterious to the other side, but neither is it harmless.

Causes

It is important to note that heart failure is not a disease itself, it is a syndrome caused by other disease, thus establishing the underlying cause of the heart's failure is vital to diagnosis and treatment. The heart muscle is either too weak to pump efficiently or not elastic enough. Heart failure is the potential end stage of all diseases of the heart. Common causes of heart failure include
coronary artery disease Coronary artery disease (CAD), also called coronary heart disease (CHD), ischemic heart disease (IHD), or simply heart disease, involves the reduction of blood flow to the heart muscle Cardiac muscle (also called heart muscle or myocardium) is ...
, including a previous
myocardial infarction A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow Hemodynamics American and British English spelling differences#ae and oe, or haemodynamics are the Fluid dynamics, dynamics of blood flow. The circulatory sy ...

(heart attack),
high blood pressure Hypertension (HTN or HT), also known as high blood pressure (HBP), is a long-term Long-Term Capital Management L.P. (LTCM) was a hedge fund''A financial History of the United States Volume II: 1970–2001'', Jerry W. Markham, Chapter 5: "Bank ...

,
atrial fibrillation Atrial fibrillation (AF or A-fib) is an abnormal heart rhythm (arrhythmia) characterized by the rapid and irregular beating of the atrial chambers of the heart. It often begins as short periods of abnormal beating, which become longer or cont ...

,
valvular heart disease Valvular heart disease is any cardiovascular disease Cardiovascular disease (CVD) is a class of diseases that involve the heart The heart is a muscle, muscular Organ (anatomy), organ in most animals, which pumps blood through the blood ...
, excess alcohol use,
infection An infection is the invasion of an organism's body by , their multiplication, and the reaction of tissues to the infectious agents and the s they produce. An infectious disease, also known as a transmissible disease or communicable disease, i ...

, and
cardiomyopathy Cardiomyopathy is a group of diseases that affect the heart muscle Cardiac muscle (also called heart muscle or myocardium) is one of three types of vertebrate Vertebrates () comprise all species of animal Animals (also called Metaz ...
of an unknown cause. In addition, viral infections of the heart can lead to inflammation of the muscular layer of the heart and subsequently contribute to the development of heart failure. Genetic predisposition plays an important role. If more than one cause is present, progression is more likely and prognosis is worse. Heart damage can predispose a person to develop heart failure later in life and has many causes including systemic viral infections (e.g.,
HIV The human immunodeficiency viruses (HIV) are two species of ''Lentivirus ''Lentivirus'' is a genus Genus (plural genera) is a taxonomic rank Taxonomy (general) is the practice and science of classification of things or concepts, inc ...
), chemotherapeutic agents such as
daunorubicin Daunorubicin, also known as daunomycin, is a chemotherapy medication Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment Cancer Cancer is a group of diseases involving abnormal cell gro ...

,
cyclophosphamide Cyclophosphamide (CP), also known as cytophosphane among other names, is a medication used as chemotherapy Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment Cancer Cancer is a group of ...

,
trastuzumab Trastuzumab, sold under the brand name Herceptin among others, is a monoclonal antibody A monoclonal antibody (mAb or moAb) is an antibody An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the i ...
and
substance use disorder Substance use disorder (SUD) is the persistent use of drugs (including alcohol) despite substantial harm and adverse consequences. Substance use disorders are characterized by an array of mental/emotional, physical, and behavioral problems such as ...
s of substances such as
alcohol In chemistry, alcohol is an organic compound that carries at least one hydroxyl functional group (−OH) bound to a Saturated and unsaturated compounds, saturated carbon atom. The term alcohol originally referred to the primary alcohol ethan ...
,
cocaine Cocaine (from , from , ultimately from Quechuan languages, Quechua: ''kúka'') is a tropane alkaloid and stimulant drug obtained primarily from the leaves of two coca species native to South America, ''Erythroxylum coca'' and ''Erythroxylu ...

, and
methamphetamine Methamphetamine (contracted from ) is a potent central nervous system (CNS) stimulant that is mainly used as a recreational drug use, recreational drug and less commonly as a second-line treatment for attention deficit hyperactivity disord ...

. An uncommon cause is exposure to certain toxins such as
lead Lead is a chemical element In chemistry, an element is a pure Chemical substance, substance consisting only of atoms that all have the same numbers of protons in their atomic nucleus, nuclei. Unlike chemical compounds, chemical elements ...

and
cobalt Cobalt is a chemical element In chemistry, an element is a pure Chemical substance, substance consisting only of atoms that all have the same numbers of protons in their atomic nucleus, nuclei. Unlike chemical compounds, chemical element ...

. Additionally, infiltrative disorders such as
amyloidosis Amyloidosis is a group of diseases in which abnormal protein Proteins are large s and s that comprise one or more long chains of . Proteins perform a vast array of functions within organisms, including , , , providing and , and from one ...

and
connective tissue disease A connective tissue disease (collagenosis) is any disease that has the connective tissue Connective tissue is one of the four basic types of animal tissue (biology), tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It deve ...
s such as
systemic lupus erythematosus Lupus, technically known as systemic lupus erythematosus (SLE), is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary between people and may be mild to severe. Co ...
have similar consequences.
Obstructive sleep apnea Obstructive sleep apnea (OSA) is the most common sleep-related breathing disorder and is characterized by recurrent episodes of complete or partial obstruction Obstruction may refer to: Places * Obstruction Island, in Washington state * Obstr ...
(a condition of sleep wherein disordered breathing overlaps with obesity, hypertension, and/or diabetes) is regarded as an independent cause of heart failure. Recent reports from
clinical trial Clinical trials are experiments or observations done in . Such prospective biomedical or behavioral research studies on are designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as no ...

s have also linked variation in blood pressure to heart failure and cardiac changes that may give rise to heart failure.

High-output heart failure

Heart failure may also occur in situations of "high output" (termed "
high-output heart failure High-output heart failure is a heart condition that occurs when the cardiac output Cardiac output (CO), also known as heart output denoted by the symbols Q, or \dot Q_ , is a term used in cardiac physiology that describes the volume of blood ...
"), where the amount of blood pumped is more than typical and the heart is unable to keep up. This can occur in overload situations (e.g., blood or serum infusions), kidney diseases, chronic severe
anemia Anemia (American and British English spelling differences#ae and oe, also spelled anaemia) is a decrease in the total amount of red blood cells (RBCs) or hemoglobin in the blood, or a lowered ability of the blood to carry oxygen. When anemia c ...

,
beriberi Thiamine deficiency is a medical condition of low levels of thiamine (vitamin B1). A severe and chronic form is known as beriberi. There are two main types in adults: wet beriberi, and dry beriberi. Wet beriberi affects the cardiovascular system ...
(vitamin B1/
thiamine Thiamine, also known as thiamin or vitamin B1, is a vitamin A vitamin is an organic molecule , CH4; is among the simplest organic compounds. In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrog ...

deficiency),
hyperthyroidism Hyperthyroidism is the condition that occurs due to excessive production of thyroid hormone File:Thyroid_system.svg, upright=1.5, The thyroid The thyroid, or thyroid gland, is an endocrine gland in vertebrates. In humans it is in the neck ...
,
cirrhosis Cirrhosis, also known as liver cirrhosis or hepatic cirrhosis, and end-stage liver disease, is the impaired liver function caused by the formation of scar tissue known as fibrosis Fibrosis, also known as fibrotic scarring, is a pathological wo ...
,
Paget's diseasePaget's disease may refer to several conditions described by Sir James Paget Sir James Paget, 1st Baronet FRS HFRSE (11 January 1814 – 30 December 1899) (, rhymes with "gadget") was an English surgeon and pathologist who is best remembered ...
,
multiple myeloma Multiple myeloma (MM), also known as plasma cell myeloma and simply myeloma, is a cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast wi ...

,
arteriovenous fistula An arteriovenous fistula is an abnormal connection or passageway between an artery An artery (plural arteries) () is a blood vessel that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arte ...
e, or
arteriovenous malformation Arteriovenous malformation is an abnormal connection between arteries and veins, bypassing the capillary system. This vascular anomaly is widely known because of its occurrence in the central nervous system (usually cerebral AVM), but can app ...
s.

Acute decompensation

Chronic stable heart failure may easily decompensate. This most commonly results from a concurrent illness (such as
myocardial infarction A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow Hemodynamics American and British English spelling differences#ae and oe, or haemodynamics are the Fluid dynamics, dynamics of blood flow. The circulatory sy ...

(a heart attack) or
pneumonia Pneumonia is an inflammatory Inflammatory may refer to: * Inflammation, a biological response to harmful stimuli * The word ''inflammatory'' is also used to refer literally to fire and flammability, and figuratively in relation to comments t ...

), abnormal heart rhythms, uncontrolled
hypertension Hypertension (HTN or HT), also known as high blood pressure (HBP), is a Chronic condition, long-term Disease, medical condition in which the blood pressure in the artery, arteries is persistently elevated. High blood pressure usually does not ...

, or a person's failure to maintain a fluid restriction, diet, or medication. Other factors that may worsen CHF include: anemia, hyperthyroidism, excessive fluid or salt intake, and medication such as NSAIDs and
thiazolidinedione The thiazolidinediones , abbreviated as TZD, also known as glitazones after the prototypical drug ciglitazone, are a class of heterocyclic compounds consisting of a five-membered C3NS ring. The term usually refers to a family of drugs used in th ...

s. NSAIDs increase the risk twofold.

Medications

A number of medications may cause or worsen the disease. This includes NSAIDS,
COX-2 inhibitor COX-2 inhibitors are a type of nonsteroidal anti-inflammatory drug Nonsteroidal anti-inflammatory drugs (NSAIDs) are members of a drug class that reduces pain, decreases fever, prevents blood clots, and in higher doses, decreases inflammatio ...
s, a number of
anesthetic An anesthetic (American English American English (AmE, AE, AmEng, USEng, en-US), sometimes called United States English or U.S. English, is the set of varieties of the English language native to the United States. Currently, American Engl ...
agents such as
ketamine Ketamine is a medication primarily used for starting and maintaining anesthesia Anesthesia or anaesthesia (from Greek "without sensation") is a state of controlled, temporary loss of sensation or awareness that is induced for medical purp ...

, thiazolidinediones, some Cancer#Medication, cancer medications, several antiarrhythmic agent, antiarrhythmic medications, pregabalin, alpha-2 adrenergic receptor agonists, minoxidil, itraconazole, cilostazol, anagrelide, stimulants (e.g., methylphenidate), tricyclic antidepressants, lithium (medication), lithium, antipsychotics, dopamine agonists, TNF inhibitors, calcium channel blockers (especially verapamil and diltiazem), salbutamol, and tamsulosin. By inhibiting the formation of prostaglandins, NSAIDs may exacerbate heart failure through several mechanisms, including promotion of fluid retention, increasing systemic vascular resistance, blood pressure, and decreasing a person's response to diuretic medications. Similarly, the ACC/AHA recommends against the use of COX-2 inhibitor medications in people with heart failure. Thiazolidinediones have been strongly linked to new cases of heart failure and worsening of pre-existing congestive heart failure due to their association with weight gain and fluid retention. Certain calcium channel blockers, such as diltiazem and verapamil, are known to Inotrope#Negative inotropic agents, decrease the force with which the heart ejects blood, thus are not recommended in people with heart failure with a reduced ejection fraction.

Supplements

Certain alternative medicines carry a risk of exacerbating existing heart failure, and are not recommended. This includes Aconitum, aconite, ginseng, gossypol, gynura, licorice, lily of the valley, tetrandrine, and yohimbine. Aconite can cause abnormally slow heart rates and abnormal heart rhythms such as ventricular tachycardia. Ginseng can cause abnormally low or high blood pressure, and may interfere with the effects of diuretic medications. Gossypol can increase the effects of diuretics, leading to toxicity. Gynura can cause low blood pressure. Licorice can worsen heart failure by increasing blood pressure and promoting fluid retention. Lily of the valley can cause abnormally slow heart rates with mechanisms similar to those of digoxin. Tetrandrine can lead to low blood pressure through inhibition of L-type calcium channels. Yohimbine can exacerbate heart failure by increasing blood pressure through alpha-2 adrenergic receptor antagonism.

Pathophysiology

Heart failure is caused by any condition that reduces the efficiency of the heart muscle, through damage or overloading. Over time, these increases in workload, which are mediated by long-term activation of neurohormonal systems such as the renin–angiotensin system, lead to fibrosis, dilation, and structural changes in the shape of the left ventricle from elliptical to spherical. The heart of a person with heart failure may have a reduced force of contraction due to overloading of the Ventricle (heart), ventricle. In a normal heart, increased filling of the ventricle results in increased contraction force by the Frank–Starling law of the heart, and thus a rise in
cardiac output Cardiac output (CO), also known as heart output denoted by the symbols Q, or \dot Q_ , is a term used in cardiac physiologyCardiac physiology or heart function is the study of healthy, unimpaired function of the heart: involving blood flow; Ca ...
. In heart failure, this mechanism fails, as the ventricle is loaded with blood to the point where heart muscle contraction becomes less efficient. This is due to reduced ability to cross-link actin and myosin filaments in over-stretched heart muscle.

Diagnosis

No diagnostic criteria have been agreed on as the Gold standard (test), gold standard for heart failure. The National Institute for Health and Care Excellence recommends measuring brain natriuretic peptide (BNP) followed by an echocardiography, ultrasound of the heart if positive. This is recommended in those with
shortness of breath Shortness of breath (SOB), also known as dyspnea (BrE British English (BrE) is the standard dialect A standard language (also standard variety, standard dialect, and standard) is a language variety that has undergone substantial codificat ...
. In those with worsening heart failure, both a BNP and a troponin are recommended to help determine likely outcomes.

Classification

One historical method of categorizing heart failure is by the side of the heart involved (left heart failure versus right heart failure). Right heart failure was thought to compromise blood flow to the lungs compared to left heart failure compromising blood flow to the aorta and consequently to the brain and the remainder of the body's systemic circulation. However, mixed presentations are common and left heart failure is a common cause of right heart failure. More accurate classification of heart failure type is made by measuring ejection fraction, or the proportion of blood pumped out of the heart during a single contraction. Ejection fraction is given as a percentage with the normal range being between 50 and 75%. The two types are: 1) Heart failure due to reduced ejection fraction (HFrEF): Synonyms no longer recommended are "heart failure due to left ventricular systolic dysfunction" and "systolic heart failure". HFrEF is associated with an ejection fraction less than 40%. 2) Heart failure with preserved ejection fraction (HFpEF): Synonyms no longer recommended include "diastolic heart failure" and "heart failure with normal ejection fraction." HFpEF occurs when the left ventricle contracts normally during systole, but the ventricle is stiff and does not relax normally during diastole, which impairs filling. Heart failure may also be classified as acute or chronic. Chronic heart failure is a long-term condition, usually kept stable by the treatment of symptoms. Acute decompensated heart failure is a worsening of chronic heart failure symptoms, which can result in acute respiratory distress. High-output heart failure can occur when there is increased cardiac demand that results in increased left ventricular diastolic pressure which can develop into pulmonary congestion (pulmonary edema). Several terms are closely related to heart failure and may be the cause of heart failure, but should not be confused with it. Cardiac arrest and asystole refer to situations in which ''no'' cardiac output occurs at all. Without urgent treatment, these result in sudden death. Myocardial infarction ("Heart attack") refers to heart muscle damage due to insufficient blood supply, usually as a result of a blocked coronary artery. Cardiomyopathy refers specifically to problems within the heart muscle, and these problems can result in heart failure. Ischemic cardiomyopathy implies that the cause of muscle damage is coronary artery disease. Dilated cardiomyopathy implies that the muscle damage has resulted in enlargement of the heart. Hypertrophic cardiomyopathy involves enlargement and ''thickening'' of the heart muscle.

Ultrasound

Echocardiography is commonly used to support a clinical diagnosis of heart failure. This modality uses ultrasound to determine the stroke volume (SV, the amount of blood in the heart that exits the ventricles with each beat), the end-diastolic volume (EDV, the total amount of blood at the end of diastole), and the SV in proportion to the EDV, a value known as the ejection fraction (EF). In pediatrics, the shortening fraction is the preferred measure of systolic function. Normally, the EF should be between 50 and 70%; in systolic heart failure, it drops below 40%. Echocardiography can also identify valvular heart disease and assess the state of the pericardium (the connective tissue sac surrounding the heart). Echocardiography may also aid in deciding what treatments will help the person, such as medication, insertion of an implantable cardioverter-defibrillator, or
cardiac resynchronization therapy Cardiac resynchronisation therapy (CRT or CRT-P) is the insertion of electrode An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit (e.g. a semiconductor A semiconductor material has an Electric ...
. Echocardiography can also help determine if acute myocardial ischemia is the precipitating cause, and may manifest as regional wall motion abnormalities on echo. File:UOTW 48 - Ultrasound of the Week 1.webm, Ultrasound showing severe systolic heart failure File:UOTW 48 - Ultrasound of the Week 2.webm, Ultrasound showing severe systolic heart failure File:UOTW 48 - Ultrasound of the Week 3.webm, Ultrasound of the lungs showing edema due to severe systolic heart failure File:UOTW 48 - Ultrasound of the Week 4.webm, Ultrasound showing severe systolic heart failure File:UOTW 48 - Ultrasound of the Week 5.jpg, Ultrasound showing severe systolic heart failure

Chest X-ray

Chest X-rays are frequently used to aid in the diagnosis of CHF. In a person who is compensated, this may show cardiomegaly (visible enlargement of the heart), quantified as the cardiothoracic ratio (proportion of the heart size to the chest). In left ventricular failure, evidence may exist of vascular redistribution (upper lobe blood diversion or cephalization), Kerley lines, peribronchial cuffing, cuffing of the areas around the bronchi, and interstitial edema. Ultrasound of the lung may also be able to detect Kerley lines. File:CHF2016.png, Congestive heart failure with small bilateral effusions File:Kerley b lines.jpg, Kerley B lines

Electrophysiology

An electrocardiogram (ECG/EKG) may be used to identify arrhythmias, ischemic heart disease, Right ventricular hypertrophy, right and left ventricular hypertrophy, and presence of conduction delay or abnormalities (e.g. left bundle branch block). Although these findings are not specific to the diagnosis of heart failure, a normal ECG virtually excludes left ventricular systolic dysfunction.

Blood tests

Blood test A blood test is a laboratory A laboratory (; ; colloquially lab) is a facility that provides controlled conditions in which or technological research, s, and may be performed. Laboratory services are provided in a variety of settings: ...

s routinely performed include electrolytes (sodium, potassium), measures of kidney function, liver function tests, thyroid function tests, a complete blood count, and often C-reactive protein if infection is suspected. An elevated brain natriuretic peptide (BNP) is a specific test indicative of heart failure. Additionally, BNP can be used to differentiate between causes of dyspnea due to heart failure from other causes of dyspnea. If myocardial infarction is suspected, various cardiac markers may be used. BNP is a better indicator than N-terminal pro-BNP for the diagnosis of symptomatic heart failure and left ventricular systolic dysfunction. In symptomatic people, BNP had a Sensitivity and specificity#Sensitivity, sensitivity of 85% and Sensitivity and specificity#Specificity, specificity of 84% in detecting heart failure; performance declined with increasing age. Hyponatremia (low serum sodium concentration) is common in heart failure. Vasopressin levels are usually increased, along with renin, angiotensin II, and catecholamines to compensate for reduced circulating volume due to inadequate cardiac output. This leads to increased fluid and sodium retention in the body; the rate of fluid retention is higher than the rate of sodium retention in the body, this phenomenon causes hypervolemic hyponatremia (low sodium concentration due to high body fluid retention). This phenomenon is more common in older women with low body mass. Severe hyponatremia can result in accumulation of fluid in the brain, causing cerebral edema and intracranial hemorrhage.

Angiography

Angiography is the X-ray imaging of blood vessels, which is done by injecting contrast agents into the Circulatory system, bloodstream through a thin plastic tube (catheter), which is placed directly in the blood vessel. X-ray images are called angiograms. Heart failure may be the result of coronary artery disease, and its prognosis depends in part on the ability of the coronary artery, coronary arteries to supply blood to the myocardium (heart muscle). As a result, coronary catheterization may be used to identify possibilities for revascularisation through percutaneous coronary intervention or Coronary artery bypass surgery, bypass surgery.

Algorithms

Various algorithms are used for the diagnosis of heart failure. For example, the algorithm used by the Framingham Heart Study adds together criteria mainly from physical examination. In contrast, the more extensive algorithm by the European Society of Cardiology weights the difference between supporting and opposing parameters from the medical history, physical examination, further medical tests, and response to therapy.

Framingham criteria

By the Framingham criteria, diagnosis of congestive heart failure (heart failure with impaired pumping capability) requires the simultaneous presence of at least two of the following major criteria or one major criterion in conjunction with two of the minor criteria. Major criteria include an Cardiomegaly, enlarged heart on a chest X-ray, an S3 gallop (a third heart sound), acute pulmonary edema, paroxysmal nocturnal dyspnea, episodes of waking up from sleep gasping for air, crackles on lung auscultation, central venous pressure more than 16 cm at the right atrium, jugular vein distension, positive abdominojugular test, and weight loss more than 4.5 kg in 5 days in response to treatment (sometimes classified as a minor criterion). In turn citing: Minor criteria include an tachycardia, abnormally fast heart rate more than 120 beats per minute, nocturnal cough, dyspnea, difficulty breathing with physical activity,
pleural effusion A pleural effusion is accumulation of excessive fluid in the pleural space, the potential space that surrounds each lung. Under normal conditions, pleural fluid is secreted by the parietal pleural capillaries at a rate of 0.01 millilitre per kilo ...

, a decrease in the vital capacity by one-third from maximum recorded, liver enlargement, and bilateral ankle edema. Minor criteria are acceptable only if they can not be attributed to another medical condition such as
pulmonary hypertension Pulmonary hypertension (PH or PHTN) is a condition of increased blood pressure within the arteries of the lungs. Symptoms include shortness of breath, syncope, tiredness, chest pain, pedal edema, swelling of the legs, and a fast heartbeat. The ...
, Chronic obstructive pulmonary disease, chronic lung disease,
cirrhosis Cirrhosis, also known as liver cirrhosis or hepatic cirrhosis, and end-stage liver disease, is the impaired liver function caused by the formation of scar tissue known as fibrosis Fibrosis, also known as fibrotic scarring, is a pathological wo ...
, ascites, or the nephrotic syndrome. The Framingham Heart Study criteria are 100% sensitive and 78% specific for identifying persons with definite congestive heart failure.

ESC algorithm

The European Society of Cardiology, ESC algorithm weights these parameters in establishing the diagnosis of heart failure:

Staging

Heart failure is commonly stratified by the degree of functional impairment conferred by the severity of the heart failure (as reflected in the New York Heart Association Functional Classification, New York Heart Association (NYHA) Functional Classification.) The NYHA functional classes (I-IV) begin with class I, which is defined as a person who experiences no limitation in any activities and has no symptoms from ordinary activities. People with NYHA class II heart failure have slight, mild limitations with everyday activities; the person is comfortable at rest or with mild exertion. With NYHA class III heart failure, a marked limitation occurs with any activity; the person is comfortable only at rest. A person with NYHA class IV heart failure is symptomatic at rest and becomes quite uncomfortable with any physical activity. This score documents the severity of symptoms and can be used to assess response to treatment. While its use is widespread, the NYHA score is not very reproducible and does not reliably predict the walking distance or exercise tolerance on formal testing. In its 2001 guidelines, the American College of Cardiology/American Heart Association working group introduced four stages of heart failure: * Stage A: People at high risk for developing HF in the future, but no functional or structural heart disorder * Stage B: A structural heart disorder, but no symptoms at any stage * Stage C: Previous or current symptoms of heart failure in the context of an underlying structural heart problem, but managed with medical treatment * Stage D: Advanced disease requiring hospital-based support, a heart transplant, or palliative care The ACC staging system is useful since stage A encompasses "pre-heart failure" – a stage where intervention with treatment can presumably prevent progression to overt symptoms. ACC stage A does not have a corresponding NYHA class. ACC stage B would correspond to NYHA class I. ACC stage C corresponds to NYHA class II and III, while ACC stage D overlaps with NYHA class IV. * The degree of coexisting illness: i.e. heart failure/systemic hypertension, heart failure/pulmonary hypertension, heart failure/diabetes, heart failure/kidney failure, etc. * Whether the problem is primarily increased venous back pressure (Preload (cardiology), preload), or failure to supply adequate arterial perfusion (afterload) * Whether the abnormality is due to low cardiac output with high systemic vascular resistance or high cardiac output with low vascular resistance (low-output heart failure vs. high-output heart failure)

Histopathology

Histopathology can diagnose heart failure in autopsy, autopsies. The presence of siderophages indicates chronic left-sided heart failure, but is not sensitivity and specificity, specific for it. It is also indicated by congestion of the pulmonary circulation.

Prevention

A person's risk of developing heart failure is inversely related to level of Physical exercise, physical activity. Those who achieved at least 500 metabolic equivalent, MET-minutes/week (the recommended minimum by U.S. guidelines) had lower heart failure risk than individuals who did not report exercising during their free time; the reduction in heart failure risk was even greater in those who engaged in higher levels of physical activity than the recommended minimum. Heart failure can also be prevented by lowering high blood pressure and high blood cholesterol, and by controlling diabetes. Maintaining a healthy weight, and decreasing sodium, alcohol, and sugar intake, may help. Additionally, avoiding tobacco use has been shown to lower the risk of heart failure. Diabetes is a major risk factor for heart failure. For women with Coronary Heart disease (CHD), diabetes was the strongest risk factor for heart failure. Diabetic women with depressed creatinine clearance or elevated BMI were at the highest risk of heart failure. While the annual incidence rate of heart failure for non-diabetic women with no risk factors is 0.4%, the annual incidence rate for diabetic women with elevated body mass index (BMI) and depressed creatinine clearance was 7% and 13%, respectively.

Management

Treatment focuses on improving the symptoms and preventing the progression of the disease. Reversible causes of heart failure also need to be addressed (e.g.
infection An infection is the invasion of an organism's body by , their multiplication, and the reaction of tissues to the infectious agents and the s they produce. An infectious disease, also known as a transmissible disease or communicable disease, i ...

, alcohol ingestion, anemia, thyrotoxicosis, Heart arrhythmia, arrhythmia, and hypertension). Treatments include lifestyle and pharmacological modalities, and occasionally various forms of device therapy. Rarely, cardiac transplantation is used as an effective treatment when heart failure has reached the end stage.

Acute decompensation

In acute decompensated heart failure, the immediate goal is to re-establish adequate perfusion and oxygen delivery to end organs. This entails ensuring that ABC (medicine), airway, breathing, and circulation are adequate. Immediate treatments usually involve some combination of vasodilators such as Nitroglycerin (medication), nitroglycerin, diuretics such as furosemide, and possibly noninvasive positive pressure ventilation. Oxygen therapy, Supplemental oxygen is indicated in those with oxygen saturation levels below 90%, but is not recommended in those with normal oxygen levels in normal atmosphere.

Chronic management

The goals of treatment for people with chronic heart failure are the prolongation of life, prevention of acute decompensation, and reduction of symptoms, allowing for greater activity. Heart failure can result from a variety of conditions. In considering therapeutic options, excluding reversible causes is of primary importance, including
thyroid disease Thyroid disease is a medical condition that affects the function of the thyroid gland. The thyroid gland is located at the front of the neck and produces thyroid hormones that travel through the blood to help regulate many other organs, meaning t ...
,
anemia Anemia (American and British English spelling differences#ae and oe, also spelled anaemia) is a decrease in the total amount of red blood cells (RBCs) or hemoglobin in the blood, or a lowered ability of the blood to carry oxygen. When anemia c ...

, chronic tachycardia, alcohol use disorder,
hypertension Hypertension (HTN or HT), also known as high blood pressure (HBP), is a Chronic condition, long-term Disease, medical condition in which the blood pressure in the artery, arteries is persistently elevated. High blood pressure usually does not ...

, and dysfunction of one or more heart valves. Treatment of the underlying cause is usually the first approach to treating heart failure. In the majority of cases, though, either no primary cause is found or treatment of the primary cause does not restore normal heart function. In these cases, behavioral treatments, behavioral, Medical treatment, medical and medical device, device treatment strategies exist that can provide a significant improvement in outcomes, including the relief of symptoms, exercise tolerance, and a decrease in the likelihood of hospitalization or death. Breathlessness rehabilitation for chronic obstructive pulmonary disease and heart failure has been proposed with exercise training as a core component. Rehabilitation should also include other interventions to address shortness of breath including psychological and educational needs of people and needs of carers. Iron supplementation appears useful in those with iron deficiency anemia and heart failure.

The latest evidence indicates that advance care planning (ACP) may help to increase documentation by medical staff regarding discussions with participants, and improve an individual's depression. This involves discussing an individual's future care plan in consideration of the individual's preferences and values. The findings are however, based on low-quality evidence.

Monitoring

The various measures often used to assess the progress of people being treated for heart failure include fluid balance (calculation of fluid intake and excretion) and monitoring body weight (which in the shorter term reflects fluid shifts). Remote monitoring can be effective to reduce complications for people with heart failure.

Lifestyle

Behavior modification is a primary consideration in chronic heart failure management program, with dietary guidelines regarding Drinking water, fluid and Sodium chloride, salt intake. Fluid restriction is important to reduce fluid retention in the body and to correct the hyponatremic status of the body. The evidence of benefit of reducing salt, however, is poor as of 2018.

Medication

First-line therapy for people with heart failure due to reduced systolic function should include ACE inhibitor, angiotensin-converting enzyme (ACE) inhibitors (ACE-I), or angiotensin receptor blockers (ARBs) if the person develops a long-term cough as a side effect of the ACE-I. Use of medicines from these classes is associated with improved survival, fewer hospitalizations for heart failure exacerbations, and improved quality of life in people with heart failure. beta blockers, Beta-adrenergic blocking agents (beta blockers) also form part of the first line of treatment, adding to the improvement in symptoms and Case fatality rate, mortality provided by ACE-I/ARB. The mortality benefits of beta blockers in people with systolic dysfunction who also have
atrial fibrillation Atrial fibrillation (AF or A-fib) is an abnormal heart rhythm (arrhythmia) characterized by the rapid and irregular beating of the atrial chambers of the heart. It often begins as short periods of abnormal beating, which become longer or cont ...

is more limited than in those who do not have it. If the ejection fraction is not diminished (HFpEF), the benefits of beta blockers are more modest; a decrease in mortality has been observed, but reduction in hospital admission for uncontrolled symptoms has not been observed. In people who are intolerant of ACE-I and ARBs or who have significant kidney dysfunction, the use of combined
hydralazine Hydralazine, sold under the brand name Apresoline among others, is a medication used to treat high blood pressure Hypertension (HTN or HT), also known as high blood pressure (HBP), is a long-term Disease, medical condition in which the blood ...

and a long-acting nitrate, such as isosorbide dinitrate, is an effective alternate strategy. This regimen has been shown to reduce mortality in people with moderate heart failure. It is especially beneficial in the black population. In people with symptomatic heart failure with markedly reduced ejection fraction (anyone with an ejection fraction of 35% or lower or less than 40% if following a heart attack), the use of an mineralocorticoid antagonist, such as spironolactone or eplerenone, in addition to beta blockers and ACE-I (once titrated to the target dose or maximum tolerated dose), can improve symptoms and reduce mortality. Sacubitril/valsartan should be used in those who still have symptoms while on an ACE inhibitor, ACE-I or Angiotensin receptor blocker, ARB, beta blocker, and a mineralocorticoid receptor antagonist as it reduces the risks of cardiovascular mortality and hospitalisation for heart failure by a further 4.7% (absolute risk reduction). However, the use of this combination agent requires the cessation of ACE-i or ARB therapy 48 hours before its initiation. Second-line medications for CHF do not confer a mortality benefit. Digoxin is one such medication. Its narrow therapeutic window, a high degree of toxicity, and the failure of multiple trials to show a mortality benefit have reduced its role in clinical practice. It is now used in only a small number of people with refractory symptoms, who are in atrial fibrillation, and/or who have chronic hypotension. Diuretics have been a mainstay of treatment against symptoms of fluid accumulation, and include diuretics classes such as loop diuretics, thiazide-like diuretics, and potassium-sparing diuretics. Although widely used, evidence on their efficacy and safety is limited, with the exception of mineralocorticoid antagonists such as spironolactone. Mineralocorticoid antagonists in those under 75 years old appear to decrease the risk of death. Anemia is an independent factor in mortality in people with chronic heart failure. Treatment of anemia significantly improves quality of life for those with heart failure, often with a reduction in severity of the NYHA classification, and also improves mortality rates. The European Society of Cardiology guideline in 2016 recommend screening for iron-deficiency anemia and treating with parenteral iron, intravenous iron if deficiency is found. The decision to anticoagulate people with HF, typically with left ventricular ejection fractions <35% is debated, but generally, people with coexisting atrial fibrillation, a prior embolic event, or conditions that increase the risk of an embolic event such as amyloidosis, left ventricular noncompaction, familial dilated cardiomyopathy, or a thromboembolic event in a first-degree relative. Vasopressin receptor antagonists can also be used to treat heart failure. Conivaptan is the first medication approved by US Food and Drug Administration for the treatment of euvolemic hyponatremia in those with heart failure. In rare cases hypertonic 3% saline together with diuretics may be used to correct hyponatremia. Ivabradine is recommended for people with symptomatic heart failure with reduced left ventricular ejection fraction who are receiving optimized guideline-directed therapy (as above) including the maximum tolerated dose of beta-blocker, have a normal heart rhythm and continue to have a resting heart rate above 70 beats per minute. Ivabradine has been found to reduce the risk of hospitalization for heart failure exacerbations in this subgroup of people with heart failure.

Implanted devices

In people with severe cardiomyopathy (left ventricular ejection fraction below 35%), or in those with recurrent VT or malignant arrhythmias, treatment with an automatic implantable cardioverter-defibrillator (AICD) is indicated to reduce the risk of severe life-threatening arrhythmias. The AICD does not improve symptoms or reduce the incidence of malignant arrhythmias but does reduce mortality from those arrhythmias, often in conjunction with antiarrhythmic medications. In people with left ventricular ejection (LVEF) below 35%, the incidence of ventricular tachycardia or sudden cardiac death is high enough to warrant AICD placement. Its use is therefore recommended in American Hospital Association, AHA/American College of Cardiology, ACC guidelines. Cardiac contractility modulation (CCM) is a Therapy, treatment for people with moderate to severe Heart#Chambers, left ventricular systolic heart failure (NYHA class II–IV), which enhances both the strength of ventricular Muscle contraction, contraction and the heart's pumping capacity. The CCM mechanism is based on stimulation of the cardiac muscle by Action potential#Refractory period, nonexcitatory electrical signals, which are delivered by a
pacemaker A cardiac pacemaker (or artificial pacemaker, so as not to be confused with the natural pacemaker of the heart The heart is a muscle, muscular Organ (anatomy), organ in most animals, which pumps blood through the blood vessels of the cir ...
-like device. CCM is particularly suitable for the treatment of heart failure with normal QRS complex duration (120 ms or less) and has been demonstrated to improve the symptoms, quality of life, and exercise tolerance. CCM is approved for use in Europe, but not currently in North America. About one-third of people with LVEF below 35% have markedly altered conduction to the ventricles, resulting in dyssynchronous depolarization of the right and left ventricles. This is especially problematic in people with left bundle branch block (blockage of one of the two primary conducting fiber bundles that originate at the base of the heart and carry depolarizing impulses to the left ventricle). Using a special pacing algorithm, biventricular
cardiac resynchronization therapy Cardiac resynchronisation therapy (CRT or CRT-P) is the insertion of electrode An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit (e.g. a semiconductor A semiconductor material has an Electric ...
(CRT) can initiate a normal sequence of ventricular depolarization. In people with LVEF below 35% and prolonged QRS duration on ECG (LBBB or QRS of 150 ms or more), an improvement in symptoms and mortality occurs when CRT is added to standard medical therapy. However, in the two-thirds of people without prolonged QRS duration, CRT may actually be harmful.

Surgical therapies

People with the most severe heart failure may be candidates for
ventricular assist device A ventricular assist device (VAD) is an electromechanics, electromechanical device for assisting cardiac circulation, which is used either to partially or to completely replace the function of a failing heart. The function of VADs is different fro ...

s, which have commonly been used as a bridge to heart transplantation, but have been used more recently as a destination treatment for advanced heart failure. In select cases, heart transplantation can be considered. While this may resolve the problems associated with heart failure, the person must generally remain on an immunosuppressive regimen to prevent rejection, which has its own significant downsides. A major limitation of this treatment option is the scarcity of hearts available for transplantation.

Palliative care

People with heart failure often have significant symptoms, such as shortness of breath and chest pain. Palliative care should be initiated early in the HF trajectory, and should not be an option of last resort. Palliative care can not only provide symptom management, but also assist with advanced care planning, goals of care in the case of a significant decline, and making sure the person has a medical power of attorney and discussed his or her wishes with this individual. A 2016 and 2017 review found that palliative care is associated with improved outcomes, such as quality of life, symptom burden, and satisfaction with care. Without transplantation, heart failure may not be reversible and heart function typically deteriorates with time. The growing number of people with stage IV heart failure (intractable symptoms of fatigue, shortness of breath, or chest pain at rest despite optimal medical therapy) should be considered for palliative care or hospice, according to American College of Cardiology/American Heart Association guidelines.

Prognosis

Prognosis in heart failure can be assessed in multiple ways, including clinical prediction rules and cardiopulmonary exercise testing. Clinical prediction rules use a composite of clinical factors such as laboratory tests and blood pressure to estimate prognosis. Among several clinical prediction rules for prognosticating acute heart failure, the 'EFFECT rule' slightly outperformed other rules in stratifying people and identifying those at low risk of death during hospitalization or within 30 days. Easy methods for identifying people that are low-risk are: * ADHERE Tree rule indicates that people with blood urea nitrogen < 43 mg/dl and systolic blood pressure at least 115 mm Hg have less than 10% chance of inpatient death or complications. * BWH rule indicates that people with systolic blood pressure over 90 mm Hg, respiratory rate of 30 or fewer breaths per minute, serum sodium over 135 mmol/l, and no new ST-T wave changes have less than 10% chance of inpatient death or complications. A very important method for assessing prognosis in people with advanced heart failure is cardiopulmonary exercise testing (CPX testing). CPX testing is usually required prior to heart transplantation as an indicator of prognosis. CPX testing involves measurement of exhaled oxygen and carbon dioxide during exercise. The peak oxygen consumption (VO2 max, VO2 max) is used as an indicator of prognosis. As a general rule, a VO2 max less than 12–14 cc/kg/min indicates poor survival and suggests that the person may be a candidate for a heart transplant. People with a VO2 max <10 cc/kg/min have a clearly poorer prognosis. The most recent International Society for Heart and Lung Transplantation guidelines also suggest two other parameters that can be used for evaluation of prognosis in advanced heart failure, the heart failure survival score and the use of a criterion of VE/VCO2 slope > 35 from the CPX test. The heart failure survival score is calculated using a combination of clinical predictors and the VO2 max from the CPX test. Heart failure is associated with significantly reduced physical and mental health, resulting in a markedly decreased quality of life. With the exception of heart failure caused by reversible conditions, the condition usually worsens with time. Although some people survive many years, progressive disease is associated with an overall annual mortality rate of 10%. Around 18 of every 1000 persons will experience an ischemic stroke during the first year after diagnosis of HF. As the duration of follow-up increases, the stroke rate rises to nearly 50 strokes per 1000 cases of HF by 5 years.

Epidemiology

In 2015, heart failure affected about 40 million people globally. Overall, around 2% of adults have heart failure and in those over the age of 65, this increases to 6–10%. Above 75 years old, rates are greater than 10%. Rates are predicted to increase. Increasing rates are mostly because of increasing lifespan, but also because of increased risk factors (hypertension, diabetes, dyslipidemia, and obesity) and improved survival rates from other types of cardiovascular disease (myocardial infarction, valvular disease, and arrhythmias). Heart failure is the leading cause of hospitalization in people older than 65.

United Kingdom

In the UK, despite moderate improvements in prevention, heart failure rates have increased due to population growth and ageing. Overall heart failure rates are similar to the four most common causes of cancer (breast, lung, prostate, and colon) combined. People from deprived backgrounds are more likely to be diagnosed with heart failure and at a younger age.

Developing world

In tropical countries, the most common cause of HF is valvular heart disease or some type of cardiomyopathy. As underdeveloped countries have become more affluent, the incidences of diabetes,
hypertension Hypertension (HTN or HT), also known as high blood pressure (HBP), is a Chronic condition, long-term Disease, medical condition in which the blood pressure in the artery, arteries is persistently elevated. High blood pressure usually does not ...

, and
obesity Obesity is a medical condition A disease is a particular abnormal condition that negatively affects the structure or function (biology), function of all or part of an organism, and that is not due to any immediate external injury. ...

have increased, which have in turn raised the incidence of heart failure.

Sex

Men have a higher incidence of heart failure, but the overall prevalence rate is similar in both sexes since women survive longer after the onset of heart failure. Women tend to be older when diagnosed with heart failure (after menopause), they are more likely than men to have diastolic dysfunction, and seem to experience a lower overall quality of life than men after diagnosis.

Ethnicity

Some sources state that people of Asian people, Asian descent are at a higher risk of heart failure than other ethnic groups. Other sources however have found that rates of heart failure are similar to rates found in other ethnic groups.

History

For centuries, the disease entity which would include many cases of what today would be called heart failure was ''dropsy''; the term denotes generalized edema, a major manifestation of a failing heart, though also caused by other diseases. Writings of ancient civilizations include evidence of their acquaintance with dropsy and heart failure: Egyptians were the first to use bloodletting to relieve fluid accumulation and shortage of breath, and provided what may have been the first documented observations on heart failure in the Ebers papurus (around 1500 BCE); Greeks described cases of dyspnea, fluid retention and fatigue compatible with heart failure; Romans used the flowering plant ''Drimia maritima'' (sea squill), which contains cardiac glycosides, for the treatment of dropsy; descriptions pertaining to heart failure are also known in the civilizations of ancient India and China. However, the manifestations of failing heart were understood in the context of these peoples' medical theories - including ancient Egyptian religion, Hippocrates, Hippocratic theory of Humours, theory of humours, or ancient Ayurveda#history, Indian and Traditional Chinese medicine, Chinese medicine, and the current concept of heart failure had not developed yet. Although shortage of breath had been connected to heart disease by Avicenna round 1000 CE, decisive for modern understanding of the nature of the condition were the description of
pulmonary circulation The mammalian heart is divided between the systemic and the pulmonary circulation, generally agreed upon as left and right sided circuits. The right circuit is the portion of the circulatory system The circulatory system, also called the ca ...
by Ibn al-Nafis in the 13th century, and of
systemic circulation The circulatory system, also called the cardiovascular system or the vascular system, is an organ system that permits blood to circulate and transport nutrients (such as amino acids and electrolytes), oxygen, carbon dioxide, hormones, and bloo ...
by William Harvey in 1628. The role of the heart in fluid retention began to be better appreciated, as ''dropsy of the chest'' (fluid accumulation in and round the lungs causing shortage of breath) became more familiar and the current concept of heart failure, which brings together swelling and shortage of breath due to fluid retention, began to be accepted, in the 17th and especially in the 18th century: Richard Lower (physician), Richard Lower linked dyspnea and foot swelling in 1679, and Giovanni Maria Lancisi connected jugular vein distention with right venticular failure in 1728. Dropsy attributable to other causes, e.g. kidney failure, was differentiated in the 19th century. The stethoscope, invented by René Laennec in 1819, x-rays, discovered by Wilhelm Röntgen in 1895, and
electrocardiography Electrocardiography is the process of producing an electrocardiogram (ECG or EKG). It is an of the which is a graph of versus time of the electrical activity of the heart using s placed on the skin. These electrodes detect the small electri ...
, described by Willem Einthoven in 1903, facilitated the investigation of heart failure. 19th century also saw experimental and conceptual advances in the physiology of heart contraction, which led to the formulation of the Frank-Starling law of the heart (named after physiologists Otto Frank (physiologist), Otto Frank and Ernest Starling, a remarkable advance in understanding mechanisms of heart failure. One of the earliest treatments of heart failure, relief of swelling by bloodletting with various methods, including Hirudo medicinalis#Medical usage, leeches, continued through the centuries. Along with bloodletting, Jean-Baptiste de Sénac in 1749 recommended opiates for acute shortage of breath due to heart failure. In 1785, William Withering described the therapeutic uses of the foxglove genus of plants in the treatment of edema; their extract contains cardiac glycosides, including digoxin, still used today in the treatment of heart failure. The Mercurial diuretic, diuretic effects of inorganic mercury salts, which were used to treat syphilis, had already been noted in the 16th century by Paracelsus;Eknoyan G (1996
Historical note. On the contributions of Paracelsus to nephrology.
''Nephrol Dial Transplant'' 11 (7):1388-94. PMID
8672051
/ref> in the 19th century they were used by noted physicians like John Blackall and William Stokes (physician), William Stokes. In the meantime, cannulae (tubes) invented by English physician Reginald Southey in 1877 was another method of removing excess fluid by directly inserting into swollen limbs. Use of organic mercury compounds as diuretics, beyond their role in syphilis treatment, started in 1920, though it was limited by their Route of administration#Parenteral, parenteral route of administration and their side-effects. Oral mercurial diuretics were introduced in the 1950s; so were thiazide diuretics, which caused less toxicity, and are still used today. Around the same time, invention of echocardiography by Inge Edler and Carl Hellmuth Hertz, Hellmuth Hertz in 1954 marked a new era in the evaluation of heart failure. In the 1960s, loop diuretics were added to available treatments of fluid retention, while a patient with heart failure received the first heart transplant by Christiaan Barnard. Over the following decades, new drug classes found their place in heart failure therapeutics, including vasodilation, vasodilators like
hydralazine Hydralazine, sold under the brand name Apresoline among others, is a medication used to treat high blood pressure Hypertension (HTN or HT), also known as high blood pressure (HBP), is a long-term Disease, medical condition in which the blood ...

; renin-angiotensin system inhibitors; and beta-blockers.

Economics

In 2011, nonhypertensive heart failure was one of the 10 most expensive conditions seen during inpatient hospitalizations in the U.S., with aggregate inpatient hospital costs more than $10.5 billion. Heart failure is associated with a high health expenditure, mostly because of the cost of hospitalizations; costs have been estimated to amount to 2% of the total budget of the National Health Service in the United Kingdom, and more than$35 billion in the United States.

Research directions

Some low-quality evidence indicates that stem cell therapy may help. Although this evidence positively indicated benefit, the evidence was of lower quality than other evidence that does not indicate benefit. There is tentative evidence of longer life expectancy and improved left ventricular ejection fraction in persons treated with bone marrow-derived stem cells.