A congenital heart defect (CHD), also known as a congenital heart anomaly, congenital cardiovascular malformation, and congenital heart disease, is a defect in the structure of the

heart The heart is a muscular Organ (biology), organ found in humans and other animals. This organ pumps blood through the blood vessels. The heart and blood vessels together make the circulatory system. The pumped blood carries oxygen and nutrie ...

great vessels Great vessels are the large vessels that bring blood to and from the heart. These are: * Superior vena cava * Inferior vena cava * Pulmonary arteries * Pulmonary veins * Aorta Transposition of the great vessels is a group of congenital A b ...

that is present at

birth Birth is the act or process of bearing or bringing forth offspring, also referred to in technical contexts as parturition. In mammals, the process is initiated by hormones which cause the muscular walls of the uterus to contract, expelling the f ...

. A congenital heart defect is classed as a

cardiovascular disease Cardiovascular disease (CVD) is any disease involving the heart or blood vessels. CVDs constitute a class of diseases that includes: coronary artery diseases (e.g. angina, heart attack), heart failure, hypertensive heart disease, rheumati ...

. Signs and symptoms depend on the specific type of defect. Symptoms can vary from none to life-threatening. When present, symptoms are variable and may include rapid breathing, bluish skin (

cyanosis Cyanosis is the change of Tissue (biology), tissue color to a bluish-purple hue, as a result of decrease in the amount of oxygen bound to the hemoglobin in the red blood cells of the capillary bed. Cyanosis is apparent usually in the Tissue (bi ...

), poor weight gain, and feeling tired. CHD does not cause chest pain. Most congenital heart defects are not associated with other diseases. A complication of CHD is

heart failure Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome caused by an impairment in the heart's ability to Cardiac cycle, fill with and pump blood. Although symptoms vary based on which side of the heart is affected, HF ...

. Congenital heart defects are the most common

birth defect A birth defect is an abnormal condition that is present at birth, regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities can range from mild to severe. Birth de ...

. In 2015, they were present in 48.9 million people globally. They affect between 4 and 75 per 1,000 live births, depending upon how they are diagnosed. In about 6 to 19 per 1,000 they cause a moderate to severe degree of problems. Congenital heart defects are the leading cause of birth defect-related deaths: in 2015, they resulted in 303,300 deaths, down from 366,000 deaths in 1990. The cause of a congenital heart defect is often unknown. Risk factors include certain infections during

pregnancy Pregnancy is the time during which one or more offspring gestation, gestates inside a woman's uterus. A multiple birth, multiple pregnancy involves more than one offspring, such as with twins. Conception (biology), Conception usually occurs ...

such as

rubella Rubella, also known as German measles or three-day measles, is an infection caused by the rubella virus. This disease is often mild, with half of people not realizing that they are infected. A rash may start around two weeks after exposure and ...

, use of certain medications or drugs such as

alcohol Alcohol may refer to: Common uses * Alcohol (chemistry), a class of compounds * Ethanol, one of several alcohols, commonly known as alcohol in everyday life ** Alcohol (drug), intoxicant found in alcoholic beverages ** Alcoholic beverage, an alco ...

tobacco Tobacco is the common name of several plants in the genus '' Nicotiana'' of the family Solanaceae, and the general term for any product prepared from the cured leaves of these plants. More than 70 species of tobacco are known, but the ...

, parents being closely related, or poor nutritional status or

obesity Obesity is a medical condition, considered by multiple organizations to be a disease, in which excess Adipose tissue, body fat has accumulated to such an extent that it can potentially have negative effects on health. People are classifi ...

in the mother. Having a parent with a congenital heart defect is also a risk factor. A number of genetic conditions are associated with heart defects, including Down syndrome,

Turner syndrome Turner syndrome (TS), commonly known as 45,X, or 45,X0,Also written as 45,XO. is a chromosomal disorder in which cells of females have only one X chromosome instead of two, or are partially missing an X chromosome (sex chromosome monosomy) lea ...

, and

Marfan syndrome Marfan syndrome (MFS) is a multi-systemic genetic disorder that affects the connective tissue. Those with the condition tend to be tall and thin, with dolichostenomelia, long arms, legs, Arachnodactyly, fingers, and toes. They also typically ha ...

. Congenital heart defects are divided into two main groups: cyanotic heart defects and non-cyanotic heart defects, depending on whether the child has the potential to turn bluish in color. The defects may involve the interior walls of the heart, the

heart valves A heart valve is a biological one-way valve that allows blood to flow in one direction through the chambers of the heart. A mammalian heart usually has four valves. Together, the valves determine the direction of blood flow through the heart. Hea ...

, or the large blood vessels that lead to and from the heart. Congenital heart defects are partly preventable through rubella vaccination, the adding of

iodine Iodine is a chemical element; it has symbol I and atomic number 53. The heaviest of the stable halogens, it exists at standard conditions as a semi-lustrous, non-metallic solid that melts to form a deep violet liquid at , and boils to a vi ...

to salt, and the adding of

folic acid Folate, also known as vitamin B9 and folacin, is one of the B vitamins. Manufactured folic acid, which is converted into folate by the body, is used as a dietary supplement and in food fortification as it is more stable during processing and ...

to certain food products. Some defects do not need treatment. Others may be effectively treated with catheter based procedures or heart surgery. Occasionally a number of operations may be needed, or a

heart transplant A heart transplant, or a cardiac transplant, is a surgical transplant procedure performed on patients with end-stage heart failure when other medical or surgical treatments have failed. , the most common procedure is to take a functioning heart ...

may be required. With appropriate treatment, outcomes are generally good, even with complex problems.

Signs and symptoms

Signs and symptoms are related to type and severity of the heart defect. Symptoms frequently present early in life, but it is possible for some CHDs to go undetected throughout life. Some children have no signs while others may exhibit shortness of breath,

fainting Syncope , commonly known as fainting or passing out, is a loss of consciousness and muscle strength characterized by a fast onset, short duration, and spontaneous recovery. It is caused by a decrease in blood flow to the brain, typically from ...

heart murmur Heart murmurs are unique heart sounds produced when blood flows across a heart valve or blood vessel. This occurs when turbulent blood flow creates a sound loud enough to hear with a stethoscope. The sound differs from normal heart sounds by th ...

, under-development of limbs and muscles, poor feeding or growth, or respiratory infections. Congenital heart defects cause abnormal heart structure resulting in production of certain sounds called

. These can sometimes be detected by

auscultation Auscultation (based on the Latin verb ''auscultare'' "to listen") is listening to the internal sounds of the body, usually using a stethoscope. Auscultation is performed for the purposes of examining the circulatory system, circulatory and resp ...

; however, not all heart murmurs are caused by congenital heart defects.

Associated conditions

Congenital heart defects are associated with an increased incidence of seven other specific medical conditions, together being called the VACTERL association: * V — Vertebral anomalies * A — Anal atresia * C — Cardiovascular anomalies * T — Tracheoesophageal fistula * E — Esophageal atresia * R — Renal (Kidney) and/or

radial Radial is a geometric term of location which may refer to: Mathematics and Direction * Vector (geometric), a line * Radius, adjective form of * Radial distance (geometry), a directional coordinate in a polar coordinate system * Radial set * A ...

anomalies * L — Limb defects

Ventricular septal defect A ventricular septal defect (VSD) is a defect in the ventricular septum, the wall dividing the left and right ventricles of the heart. It's a common heart problem present at birth ( congenital heart defect). The extent of the opening may vary ...

(VSD),

atrial septal defect Atrial septal defect (ASD) is a congenital heart defect in which blood flows between the atrium (heart), atria (upper chambers) of the heart. Some flow is a normal condition both pre-birth and immediately post-birth via the Foramen ovale (heart) ...

(ASD), and

tetralogy of Fallot Tetralogy of Fallot (TOF), formerly known as Steno-Fallot tetralogy, is a congenital heart defect characterized by four specific cardiac defects. Classically, the four defects are: * Pulmonary stenosis, which is narrowing of the exit from the r ...

(ToF) are the most common congenital heart defects seen in the VACTERL association. Less common defects in the association are

persistent truncus arteriosus Persistent truncus arteriosus (PTA), often referred to simply as truncus arteriosus, is a rare form of congenital heart disease that presents at birth. In this condition, the embryological structure known as the truncus arteriosus (embryology), t ...

and transposition of the great arteries.

Causes

The cause of congenital heart disease may be genetic, environmental, or a combination of both.

Genetic

Genetic mutations In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mitosi ...

, often sporadic, represent the largest known cause of congenital heart defects. They are described in the table below.

Molecular pathways

The genes regulating the complex developmental sequence have only been partly elucidated. Some genes are associated with specific defects. A number of genes have been associated with cardiac manifestations. Mutations of a heart muscle protein, α-myosin heavy chain ( MYH6) are associated with atrial septal defects. Several proteins that interact with MYH6 are also associated with cardiac defects. The transcription factor GATA4 forms a complex with the

TBX5 T-box transcription factor TBX5, (T-box protein 5) is a protein that in humans is encoded by the ''TBX5'' gene. Abnormalities in the TBX5 gene can result in altered limb development, Holt-Oram syndrome, Tetra-amelia syndrome, and cardiac and s ...

which interacts with MYH6. Another factor, the

homeobox A homeobox is a Nucleic acid sequence, DNA sequence, around 180 base pairs long, that regulates large-scale anatomical features in the early stages of embryonic development. Mutations in a homeobox may change large-scale anatomical features of ...

(developmental) gene,

NKX2-5 Homeobox protein Nkx-2.5 is a protein that in humans is encoded by the ''NKX2-5'' gene. Function Homeobox-containing genes play critical roles in regulating tissue-specific gene expression essential for tissue differentiation, as well as deter ...

also interacts with MYH6. Mutations of all these proteins are associated with both atrial and ventricular septal defects; In addition, NKX2-5 is associated with defects in the electrical conduction of the heart and TBX5 is related to the

Holt–Oram syndrome Holt–Oram syndrome (also called atrio-digital syndrome, atriodigital dysplasia, cardiac-limb syndrome, heart-hand syndrome type 1, HOS, ventriculo-radial syndrome) is an autosomal dominant disorder that affects bones in the arms and hands (th ...

which includes electrical conduction defects and abnormalities of the upper limb. The Wnt signaling co-factors

BCL9 B-cell CLL/lymphoma 9 protein is a protein that in humans is encoded by the ''BCL9'' gene. Function BCL9, together with its paralogue gene BCL9L (BCL9 like or BCL9.2), have been extensively studied for their role as transcriptional beta-caten ...

, BCL9L and PYGO might be part of these molecular pathways, as when their genes are mutated, this causes phenotypes similar to the features present in Holt-Oram syndrome. Another T-box gene, TBX1, is involved in velo-cardio-facial syndrome

DiGeorge syndrome DiGeorge syndrome, also known as 22q11.2 deletion syndrome, is a syndrome caused by a microdeletion on the long arm of chromosome 22. While the symptoms can vary, they often include congenital heart problems, specific facial features, frequent ...

, the most common deletion which has extensive symptoms including defects of the cardiac outflow tract including

. The

notch signaling pathway The Notch signaling pathway is a highly Conserved sequence, conserved cell signaling system present in most animal, animals. Mammals possess four different Notch proteins, notch receptors, referred to as NOTCH1, NOTCH2, Notch 3, NOTCH3, and NOTC ...

, a regulatory mechanism for

cell growth Cell most often refers to: * Cell (biology), the functional basic unit of life * Cellphone, a phone connected to a cellular network * Clandestine cell, a penetration-resistant form of a secret or outlawed organization * Electrochemical cell, a de ...

and differentiation, plays broad roles in several aspects of cardiac development. Notch elements are involved in determination of the right and left sides of the body plan, so the directional folding of the heart tube can be impacted. Notch signaling is involved early in the formation of the endocardial cushions and continues to be active as the develop into the septa and valves. It is also involved in the development of the ventricular wall and the connection of the outflow tract to the great vessels.

Mutations In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mitosi ...

in the gene for one of the notch ligands, '' Jagged1'', are identified in the majority of examined cases of arteriohepatic dysplasia ( Alagille syndrome), characterized by defects of the great vessels (pulmonary artery stenosis), heart (

in 13% of cases), liver, eyes, face, and bones. Though less than 1% of all cases, where no defects are found in the ''Jagged1'' gene, defects are found in '' Notch2'' gene. In 10% of cases, no mutation is found in either gene. For another member of the

gene family A gene family is a set of several similar genes, formed by duplication of a single original gene, and generally with similar biochemical functions. One such family are the genes for human hemoglobin subunits; the ten genes are in two clusters on ...

, mutations in the '' Notch1'' gene are associated with

bicuspid aortic valve Bicuspid aortic valve (BAV) is a form of heart disease in which two of the leaflets of the aortic valve fuse during development in the womb resulting in a two-leaflet (bicuspid) valve instead of the normal three-leaflet (tricuspid) valve. BAV is ...

, a valve with two leaflets instead of three. ''Notch1'' is also associated with calcification of the aortic valve, the third most common cause of heart disease in adults. Mutations of a cell regulatory mechanism, the Ras/

MAPK A mitogen-activated protein kinase (MAPK or MAP kinase) is a type of serine/threonine-specific protein kinases involved in directing cellular responses to a diverse array of stimuli, such as mitogens, osmotic stress, heat shock and proinflamm ...

pathway are responsible for a variety of syndromes, including Noonan syndrome, LEOPARD syndrome, Costello syndrome and cardiofaciocutaneous syndrome in which there is cardiac involvement. While the conditions listed are known genetic causes, there are likely many other genes which are more subtle. It is known that the risk for congenital heart defects is higher when there is a close relative with one.

Environmental

Known environmental factors include certain

infection An infection is the invasion of tissue (biology), tissues by pathogens, their multiplication, and the reaction of host (biology), host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmis ...

s during pregnancy such as

drugs A drug is any chemical substance other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect. Consumption of drugs can be via inhalation, injection, smoking, ingestio ...

(

hydantoin Hydantoin, or glycolylurea, is a heterocyclic organic compound with the formula CH2C(O)NHC(O)NH. It is a colorless solid that arises from the reaction of glycolic acid and urea. It is an oxidized derivative of imidazolidine. In a more general sen ...

lithium Lithium (from , , ) is a chemical element; it has chemical symbol, symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard temperature and pressure, standard conditions, it is the least dense metal and the ...

and

thalidomide Thalidomide, sold under the brand names Contergan and Thalomid among others, is an oral administered medication used to treat a number of cancers (e.g., multiple myeloma), graft-versus-host disease, and many skin disorders (e.g., complication ...

) and maternal illness (

diabetes mellitus Diabetes mellitus, commonly known as diabetes, is a group of common endocrine diseases characterized by sustained hyperglycemia, high blood sugar levels. Diabetes is due to either the pancreas not producing enough of the hormone insulin, or th ...

phenylketonuria Phenylketonuria (PKU) is an inborn error of metabolism that results in decreased metabolism of the amino acid phenylalanine. Untreated PKU can lead to intellectual disability, seizures, behavioral problems, and mental disorders. It may also r ...

, and

systemic lupus erythematosus Lupus, formally called 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 among people and may be mild to severe. Common ...

). Alcohol exposure in the father also appears to increase the risk of congenital heart defects. Being

overweight Being overweight is having more body fat than is optimally healthy. Being overweight is especially common where food supplies are plentiful and lifestyles are sedentary. , excess weight reached epidemic proportions globally, with more than ...

obese Obesity is a medical condition, considered by multiple organizations to be a disease, in which excess body fat has accumulated to such an extent that it can potentially have negative effects on health. People are classified as obese when ...

increases the risk of congenital heart disease. Additionally, as maternal obesity increases, the risk of heart defects also increases. A distinct physiological mechanism has not been identified to explain the link between maternal obesity and CHD, but both pre-pregnancy

folate deficiency Folate deficiency, also known as vitamin B9 deficiency, is a low level of folate and derivatives in the body. This may result in megaloblastic anemia in which red blood cells become abnormally large, and folate deficiency anemia is the term given ...

and diabetes have been implicated in some studies.

Twins and Multiple Births

Congenital heart defects happen more often in twins than in single babies. Monochorionic twins, who share a placenta, have a greater risk of these heart defects compared to dichorionic twins, who have their own placentas. A systematic review and meta-analysis of four studies conducted in 2007 showed a 9-fold increase in CHD risk in MC twins compared to singletons.

Mechanism

There is a complex sequence of events that result in a well formed heart at birth and disruption of any portion may result in a defect. The orderly timing of cell growth, cell migration, and programmed cell death ("

apoptosis Apoptosis (from ) is a form of programmed cell death that occurs in multicellular organisms and in some eukaryotic, single-celled microorganisms such as yeast. Biochemistry, Biochemical events lead to characteristic cell changes (Morphology (biol ...

") has been studied extensively and the genes that control the process are being elucidated. Around day 15 of development, the cells that will become the heart exist in two horseshoe shaped bands of the middle tissue layer (

mesoderm The mesoderm is the middle layer of the three germ layers that develops during gastrulation in the very early development of the embryo of most animals. The outer layer is the ectoderm, and the inner layer is the endoderm.Langman's Medical ...

), and some cells migrate from a portion of the outer layer (

ectoderm The ectoderm is one of the three primary germ layers formed in early embryonic development. It is the outermost layer, and is superficial to the mesoderm (the middle layer) and endoderm (the innermost layer). It emerges and originates from the o ...

), the

neural crest The neural crest is a ridge-like structure that is formed transiently between the epidermal ectoderm and neural plate during vertebrate development. Neural crest cells originate from this structure through the epithelial-mesenchymal transition, ...

, which is the source of a variety of cells found throughout the body. On day 19 of development, a pair of vascular elements, the "endocardial tubes", form. The tubes fuse when cells between then undergo programmed death and cells from the first heart field migrate to the tube, and form a ring of heart cells (

myocyte A muscle cell, also known as a myocyte, is a mature contractile Cell (biology), cell in the muscle of an animal. In humans and other vertebrates there are three types: skeletal muscle, skeletal, smooth muscle, smooth, and Cardiac muscle, cardiac ...

s) around it by day 21. On day 22, the heart begins to beat and by day 24, blood is circulating. At day 22, the circulatory system is bilaterally symmetrical with paired vessels on each side and the heart consisting of a simple tube located in the midline of the body layout. The portions that will become the atria and will be located closest to the head are the most distant from the head. From days 23 through 28, the heart tube folds and twists, with the future ventricles moving left of center (the ultimate location of the heart) and the atria moving towards the head. On day 28, areas of tissue in the heart tube begin to expand inwards; after about two weeks, these expansions (the membranous " septum primum" and the muscular "

endocardial cushions Endocardial cushions, or atrioventricular cushions, refer to a subset of cells in the development of the heart that play a vital role in the proper formation of the heart septa. They develop on the atrioventricular canal and conotruncal region of ...

") fuse to form the four chambers of the heart. A failure to fuse properly will result in a defect that may allow blood to leak between chambers. After this happens, cells that have migrated from the neural crest begin to divide the bulbus cordis. The main outflow tract is divided in two by the growth of a spiraling septum, becoming the great vessels—the ascending segment of the aorta and the pulmonary trunk. If the separation is incomplete, the result is a "persistent truncus arteriosus". The vessels may be reversed ("

transposition of the great vessels Transposition of the great vessels (TGV) is a group of congenital heart defects involving an abnormal spatial arrangement of any of the great vessels: superior and/or inferior venae cavae, pulmonary artery, pulmonary veins, and aorta. Congen ...

"). The two halves of the split tract must migrate into the correct positions over the appropriate ventricles. A failure may result in some blood flowing into the wrong vessel (''e.g.'' overriding aorta). The four-chambered heart and the great vessels have features required for fetal growth. The lungs are unexpanded and cannot accommodate the full circulatory volume. Two structures exist to shunt blood flow away from the lungs to compensate. Cells in part of the septum primum die, creating a hole while new muscle cells (the " septum secundum") grow along the right atrial side of the septum primum except for one region, leaving a gap through which blood can pass from the right atrium to the left atrium (the foramen ovale). A small vessel called the ''

ductus arteriosus The ductus arteriosus, also called the ductus Botalli, named after the Italian physiologist Leonardo Botallo, is a blood vessel in the developing fetus connecting the trunk of the pulmonary artery to the proximal descending aorta. It allows mos ...

'' allows blood from the

pulmonary artery A pulmonary artery is an artery in the pulmonary circulation that carries deoxygenated blood from the right side of the heart to the lungs. The largest pulmonary artery is the ''main pulmonary artery'' or ''pulmonary trunk'' from the heart, and ...

to pass to the aorta.

Changes at birth

The ductus arteriosus stays open because of circulating factors including

prostaglandins Prostaglandins (PG) are a group of physiologically active lipid compounds called eicosanoids that have diverse hormone-like effects in animals. Prostaglandins have been found in almost every tissue in humans and other animals. They are derive ...

. The foramen ovale stays open because of the flow of blood from the right atrium to the left atrium. As the lungs expand, blood flows easily through the lungs and the membranous portion of the foramen ovale (the septum primum) flops over the muscular portion (the septum secundum). If the closure is incomplete, the result is a patent foramen ovale. The two flaps may fuse, but many adults have a foramen ovale that stays closed only because of the pressure difference between the atria.

Theories

Rokitansky (1875) explained congenital heart defects as breaks in heart development at various

ontogenesis Ontogeny (also ontogenesis) is the origination and development of an organism (both physical and psychological, e.g., moral development), usually from the time of fertilization of the egg to adult. The term can also be used to refer to the stu ...

stages. Spitzer (1923) treats them as returns to one of the

phylogenesis Phylogenesis (from Greek φῦλον ''phylon'' "tribe" + γένεσις ''genesis'' "origin") is the biological process by which a taxon (of any rank) appears. The science that studies these processes is called phylogenetics. These terms may ...

stages. Krimski (1963), synthesizing two previous points of view, considered congenital heart diseases as a stop of development at the certain stage of ontogenesis, corresponding to this or that stage of the phylogenesis. Hence, these theories can explain feminine and neutral types of defects only.

Diagnosis

Many congenital heart defects can be diagnosed prenatally by fetal echocardiography. This is a test which can be done during the second trimester of pregnancy, when the woman is about 18–24 weeks pregnant. It can be an

abdominal ultrasound Abdominal ultrasonography (also called abdominal ultrasound imaging or abdominal sonography) is a form of medical ultrasonography (medicine, medical application of ultrasound technology) to visualise abdomen, abdominal anatomy, anatomical structu ...

transvaginal ultrasound Vaginal ultrasonography is a medical ultrasonography that applies an ultrasound transducer (or "probe") in the vagina to visualize organs within the pelvic cavity. It is also called transvaginal ultrasonography because the ultrasound waves go ''a ...

. If a baby is born with cyanotic heart disease, the diagnosis is usually made shortly after birth due to the blue colour of their skin (called cyanosis). If a baby is born with a septal defect or an obstruction defect, often their symptoms are only noticeable after several months, or sometimes even after many years.

Classification

A number of classification systems exist for congenital heart defects. In 2000 the International Congenital Heart Surgery Nomenclature was developed to provide a generic classification system.

Hypoplasia

Hypoplasia Hypoplasia (; adjective form ''hypoplastic'') is underdevelopment or incomplete development of a tissue or organ.right ventricle A ventricle is one of two large chambers located toward the bottom of the heart that collect and expel blood towards the peripheral beds within the body and lungs. The blood pumped by a ventricle is supplied by an atrium (heart), atrium, an adjace ...

or the

left ventricle A ventricle is one of two large chambers located toward the bottom of the heart that collect and expel blood towards the peripheral beds within the body and lungs. The blood pumped by a ventricle is supplied by an atrium, an adjacent chamber in t ...

. This causes only one side of the heart to be capable of pumping blood to the body and

lung The lungs are the primary Organ (biology), organs of the respiratory system in many animals, including humans. In mammals and most other tetrapods, two lungs are located near the Vertebral column, backbone on either side of the heart. Their ...

s effectively. Hypoplasia of the heart is rare but is the most serious form of CHD. It is called

hypoplastic left heart syndrome Hypoplastic left heart syndrome (HLHS) is a rare congenital heart defect in which the left side of the heart is severely underdeveloped and incapable of supporting the systemic circulation. It is estimated to account for 2-3% of all congenital hea ...

when it affects the left side of the heart and

hypoplastic right heart syndrome Hypoplastic right heart syndrome (HRHS) is a congenital heart defect in which the structures on the right side of the heart, particularly the right ventricle, are underdeveloped. This defect causes inadequate blood flow to the lungs, and thus a ...

when it affects the right side of the heart. In both conditions, the presence of a

patent ductus arteriosus Patent ductus arteriosus (PDA) is a medical condition in which the ''ductus arteriosus'' fails to close after childbirth, birth: this allows a portion of oxygenated blood from the left heart to flow back to the lungs from the aorta, which has a h ...

(and, when hypoplasia affects the right side of the heart, a patent foramen ovale) is vital to the infant's ability to survive until emergency heart surgery can be performed, since without these pathways blood cannot circulate to the body (or lungs, depending on which side of the heart is defective). Hypoplasia of the heart is generally a cyanotic heart defect.

Obstructive defects

Obstructive defects occur when heart valves, arteries, or veins are abnormally narrow or blocked. Common defects include pulmonic stenosis, aortic stenosis, and

coarctation of the aorta Coarctation of the aorta (CoA) is a congenital condition whereby the aorta is narrow, usually in the area where the ductus arteriosus ( ligamentum arteriosum after regression) inserts. The word ''coarctation'' means "pressing or drawing toget ...

, with other types such as bicuspid aortic valve stenosis and subaortic stenosis being comparatively rare. Any narrowing or blockage can cause heart enlargement or

hypertension Hypertension, also known as high blood pressure, 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 cause symptoms i ...

Septal defects

The septum is a wall of tissue which separates the

left heart The heart is a muscular organ found in humans and other animals. This organ pumps blood through the blood vessels. The heart and blood vessels together make the circulatory system. The pumped blood carries oxygen and nutrients to the tissue ...

from the

right heart The heart is a muscular organ found in humans and other animals. This organ pumps blood through the blood vessels. The heart and blood vessels together make the circulatory system. The pumped blood carries oxygen and nutrients to the tiss ...

. Defects in the

interatrial septum The interatrial septum is the wall of tissue that separates the right and left atria of the heart. Structure The interatrial septum is a that lies between the left atrium and right atrium of the human heart. The interatrial septum lies at ang ...

or the

interventricular septum The interventricular septum (IVS, or ventricular septum, or during development septum inferius) is the stout wall separating the ventricle (heart), ventricles, the lower chambers of the heart, from one another. The interventricular septum is di ...

allow blood to flow from the left side of the heart to the right, reducing the heart's efficiency.

s are collectively the most common type of CHD, although approximately 30% of adults have a type of

called probe patent foramen ovale. An

atrioventricular septal defect Atrioventricular septal defect (AVSD) or atrioventricular canal defect (AVCD), also known as "common atrioventricular canal" or "endocardial cushion defect" (ECD), is characterized by a deficiency of the atrioventricular septum of the heart that c ...

is more complex involving an atrial septal defect, a ventricular septal defect, and irregularities in the

heart valve A heart valve is a biological one-way valve that allows blood to flow in one direction through the chambers of the heart. A mammalian heart usually has four valves. Together, the valves determine the direction of blood flow through the heart. Hea ...

Cyanotic defects

Cyanotic heart defects are called such because they result in

, a bluish-grey discoloration of the skin due to a lack of

oxygen Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...

in the body. Such defects include

, total anomalous pulmonary venous connection,

, and tricuspid atresia.

Defects

* Aortic stenosis *

Arrhythmogenic right ventricular cardiomyopathy Arrhythmogenic cardiomyopathy (ACM) is an inherited heart disease. ACM is caused by genetic defects of parts of the cardiac muscle known as desmosomes, areas on the surface of muscle cells which link them together. The desmosomes are composed o ...

Atrial septal defect Atrial septal defect (ASD) is a congenital heart defect in which blood flows between the atrium (heart), atria (upper chambers) of the heart. Some flow is a normal condition both pre-birth and immediately post-birth via the Foramen ovale (heart) ...

(ASD) *

Atrioventricular septal defect Atrioventricular septal defect (AVSD) or atrioventricular canal defect (AVCD), also known as "common atrioventricular canal" or "endocardial cushion defect" (ECD), is characterized by a deficiency of the atrioventricular septum of the heart that c ...

(AVSD) *

Bicuspid aortic valve Bicuspid aortic valve (BAV) is a form of heart disease in which two of the leaflets of the aortic valve fuse during development in the womb resulting in a two-leaflet (bicuspid) valve instead of the normal three-leaflet (tricuspid) valve. BAV is ...

Cardiomyopathy Cardiomyopathy is a group of primary diseases of the heart muscle. Early on there may be few or no symptoms. As the disease worsens, shortness of breath, feeling tired, and swelling of the legs may occur, due to the onset of heart failure. A ...

Complete heart block Third-degree atrioventricular block (AV block) is a medical condition in which the electrical impulse generated in the sinoatrial node (SA node) in the atrium (heart), atrium of the heart can not propagate to the ventricle (heart), ventricles. Be ...

(CHB) * Dextrocardia *

Double inlet left ventricle A double inlet left ventricle (DILV) or ''"single ventricle"'', is a congenital heart defect appearing in 5 in newborns, where both the left atrium and the right atrium feed into the left ventricle. The right ventricle is hypoplastic or does not ...

(DILV) * Double outlet right ventricle (DORV) * Ebstein's anomaly * Early Repolarization Syndrome * Holmes heart *

Hypoplastic left heart syndrome Hypoplastic left heart syndrome (HLHS) is a rare congenital heart defect in which the left side of the heart is severely underdeveloped and incapable of supporting the systemic circulation. It is estimated to account for 2-3% of all congenital hea ...

(HLHS) *

Hypoplastic right heart syndrome Hypoplastic right heart syndrome (HRHS) is a congenital heart defect in which the structures on the right side of the heart, particularly the right ventricle, are underdeveloped. This defect causes inadequate blood flow to the lungs, and thus a ...

(HRHS) *

Mitral stenosis Mitral stenosis is a valvular heart disease characterized by the Stenosis, narrowing of the opening of the mitral valve of the heart. It is almost always caused by Rheumatic Heart Disease, rheumatic valvular heart disease. Normally, the mitral va ...

* Myocardial bridge *

Persistent truncus arteriosus Persistent truncus arteriosus (PTA), often referred to simply as truncus arteriosus, is a rare form of congenital heart disease that presents at birth. In this condition, the embryological structure known as the truncus arteriosus (embryology), t ...

* Pulmonary atresia * Pulmonary stenosis * Rhabdomyomas (Tumors of the Heart) *

Transposition of the great vessels Transposition of the great vessels (TGV) is a group of congenital heart defects involving an abnormal spatial arrangement of any of the great vessels: superior and/or inferior venae cavae, pulmonary artery, pulmonary veins, and aorta. Congen ...

** dextro-Transposition of the great arteries (d-TGA) ** levo-Transposition of the great arteries (l-TGA) * Tricuspid atresia *

(VSD) * Wolff–Parkinson–White syndrome (WPW) Some conditions affect the great vessels or other vessels in close proximity to the heart, but not the heart itself, but are often classified as congenital heart defects. *

Coarctation of the aorta Coarctation of the aorta (CoA) is a congenital condition whereby the aorta is narrow, usually in the area where the ductus arteriosus ( ligamentum arteriosum after regression) inserts. The word ''coarctation'' means "pressing or drawing toget ...

(CoA) * Double aortic arch,

aberrant subclavian artery Aberrant subclavian artery, or aberrant subclavian artery syndrome, is a rare anatomical variant of the origin of the right or left subclavian artery. This abnormality is the most common Congenital disorder, congenital Blood vessel, vascular anoma ...

, and other malformations of the great arteries *

Interrupted aortic arch Interrupted aortic arch is a very rare heart defect (affecting 3 per million live births) in which the aorta is not completely developed. There is a gap between the ascending and descending thoracic aorta. In a sense it is the complete form of a coa ...

(IAA) *

Patent ductus arteriosus Patent ductus arteriosus (PDA) is a medical condition in which the ''ductus arteriosus'' fails to close after childbirth, birth: this allows a portion of oxygenated blood from the left heart to flow back to the lungs from the aorta, which has a h ...

(PDA) * Scimitar syndrome (SS) ** Partial anomalous pulmonary venous connection (PAPVC) ** Total anomalous pulmonary venous connection (TAPVC) Some constellations of multiple defects are commonly found together. *

Tetralogy of Fallot Tetralogy of Fallot (TOF), formerly known as Steno-Fallot tetralogy, is a congenital heart defect characterized by four specific cardiac defects. Classically, the four defects are: * Pulmonary stenosis, which is narrowing of the exit from the r ...

(ToF) * Pentalogy of Cantrell * Shone's syndrome/ Shone's complex / Shone's anomaly

Treatment

CHD may require surgery and medications. Medications include diuretics, which aid the body in eliminating water, salts, and digoxin for strengthening the contraction of the heart. This slows the heartbeat and removes some fluid from tissues. Some defects require surgical procedures to restore circulation back to normal and in some cases, multiple surgeries are needed. Interventional cardiology now offers minimally invasive alternatives to surgery for some patients. The Melody Transcatheter Pulmonary Valve (TPV), approved in Europe in 2006 and in the U.S. in 2010 under a Humanitarian Device Exemption (HDE), is designed to treat congenital heart disease patients with a dysfunctional conduit in their right ventricular outflow tract (RVOT). The RVOT is the connection between the heart and lungs; once blood reaches the lungs, it is enriched with oxygen before being pumped to the rest of the body. Transcatheter pulmonary valve technology provides a less-invasive means to extend the life of a failed RVOT conduit and is designed to allow physicians to deliver a replacement pulmonary valve via a catheter through the patient's blood vessels. Many people require lifelong specialized cardiac care, first with a pediatric cardiologist and later with an adult congenital cardiologist. There are more than 1.8 million adults living with congenital heart defects.

Mental health

Supporting people with chronic diseases such as congenital heart disease with emotional problems and mental health is a treatment consideration. Since some people with congenital heart disease have a lower quality of life that is related to their condition, some people may struggle with finding a job, engaging in physical exercise, with their

fertility Fertility in colloquial terms refers the ability to have offspring. In demographic contexts, fertility refers to the actual production of offspring, rather than the physical capability to reproduce, which is termed fecundity. The fertility rate ...

, and clinical depression as examples. An estimated 31% of adults with congenital heart disease also have mood disorders.

Psychotherapy Psychotherapy (also psychological therapy, talk therapy, or talking therapy) is the use of Psychology, psychological methods, particularly when based on regular Conversation, personal interaction, to help a person change behavior, increase hap ...

may be helpful for treating some people who have congenital heart disease and depression, however further research is needed to determine the best way to reduce depression including the length of treatments required for an improvement, type of psychotherapy treatments, and how the psychotherapy sessions are delivered.

Epidemiology

Congenital heart anomalies world map-Deaths per million persons-WHO2012

Heart defects are among the most common

, occurring in 1% of live births (2–3% including bicuspid aortic valve). In 2013, 34.3 million people had CHD. In 2010, they resulted in 223,000 deaths, down from 278,000 deaths in 1990. For congenital heart defects that arise without a family history (''de novo''), the recurrence risk in offspring is 3–5%. This risk is higher in left ventricular outflow tract obstructions, heterotaxy, and atrioventricular septal defects.

Terminology

Congenital heart defects are known by a number of names including congenital heart anomaly, congenital heart disease, heart defects, and congenital cardiovascular malformations.

References

External links

Congenital heart disease
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