A congenital heart defect (CHD), also known as a congenital heart anomaly or congenital heart disease, is a problem in the structure of the heart that is present at birth. Signs and symptoms depend on the specific type of problem. Symptoms can vary from none to life-threatening. When present they may include rapid breathing, bluish skin, poor weight gain, and feeling tired. It does not cause chest pain. Most congenital heart problems do not occur with other diseases. Complications that can result from heart defects include heart failure.
The cause of a congenital heart defect is often unknown. Certain cases may be due to infections during pregnancy such as rubella, use of certain medications or drugs such as alcohol or tobacco, parents being closely related, or poor nutritional status or obesity 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, and Marfan syndrome. 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 problems may involve the interior walls of the heart, the heart valves, 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 to salt, and the adding of folic acid 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 may be required. With appropriate treatment, outcomes are generally good, even with complex problems.
Heart defects are the most common birth defect. 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. About 6 to 19 per 1,000 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.
|Congenital heart defect|
|Synonyms||Congenital heart anomaly, congenital heart disease|
|The normal structure of the heart (left) in comparison to two common locations for a ventricular septal defect (right), the most common form of congenital heart defect.|
|Symptoms||Rapid breathing, bluish skin, poor weight gain, feeling tired|
|Types||Cyanotic heart defects, non-cyanotic heart defects|
|Risk factors||Rubella infection during pregnancy, alcohol or tobacco, parents being closely related, poor nutritional status or obesity in the mother|
|Treatment||None, catheter based procedures, heart surgery, heart transplantation|
|Prognosis||Generally good (with treatment)|
|Frequency||48.9 million (2015)|
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, cyanosis, fainting, heart murmur, 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 heart murmur. These can sometimes be detected by auscultation; however, not all heart murmurs are caused by congenital heart defects.
Congenital heart defects are associated with an increased incidence of some other symptoms, together being called the VACTERL association:
Ventricular septal defect (VSD), atrial septal defects, and tetralogy of Fallot are the most common congenital heart defects seen in the VACTERL association. Less common defects in the association are truncus arteriosus and transposition of the great arteries.
The cause of congenital heart disease may be genetic, environmental, or a combination of both.
Most of the known causes of congenital heart disease are sporadic genetic changes, either focal mutations or deletion or addition of segments of DNA. Large chromosomal abnormalities such as trisomies 21, 13, and 18 cause about 5–8% of cases of CHD, with trisomy 21 being the most common genetic cause. Small chromosomal abnormalities also frequently lead to congenital heart disease, and examples include microdeletion of the long arm of chromosome 22 (22q11, DiGeorge syndrome), the long arm of chromosome 1 (1q21), the short arm of chromosome 8 (8p23) and many other, less recurrent regions of the genome, as shown by high resolution genome-wide screening (Array comparative genomic hybridization).
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 which interacts with MYH6. Another factor, the homeobox (developmental) gene, NKX2-5 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 which includes electrical conduction defects and abnormalities of the upper limb. Another T-box gene, TBX1, is involved in velo-cardio-facial syndrome DiGeorge syndrome, the most common deletion which has extensive symptoms including defects of the cardiac outflow tract including tetralogy of Fallot.
|Atrial septal defects||✔||✔||✔||✔|
|Ventricular septal defects||✔||✔||✔|
|Electrical conduction abnormalities||✔||✔|
|Outflow tract abnormalities||✔|
|Non-cardiac manifestations||Upper limb abnormalities||Small or absent thymus |
Small or absent parathyroids
The notch signaling pathway, a regulatory mechanism for cell growth 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 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 (tetralogy of Fallot 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, mutations in the Notch1 gene are associated with bicuspid aortic valve, 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 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.
Known environmental factors include certain infections during pregnancy such as Rubella, drugs (alcohol, hydantoin, lithium and thalidomide) and maternal illness (diabetes mellitus, phenylketonuria, and systemic lupus erythematosus).
Being overweight or obese 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 prepregnancy folate deficiency and diabetes have been implicated in some studies.
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") 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), and some cells migrate from a portion of the outer layer (ectoderm), the neural crest, 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 (myocytes) 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", 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 which have migrated from the neural crest begin to divide the bulbus cordis, the main outflow tract is divided in two by the growth 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 arteriosis". The vessels may be reversed ("transposition of the great vessels"). 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. Cells in part of the septum primum die creating a hole while muscle cells, the "septum secundum", grow along the right atrial side the septum primum, except for one region, leaving a gap through which blood can pass from the right artium to the left atrium, the foramen ovale. A small vessel, the ductus arteriosus allows blood from the pulmonary artery to pass to the aorta.
The ductus arteriosus stays open because of circulating factors including prostaglandins. 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.
Rokitansky (1875) explained congenital heart defects as breaks in heart development at various ontogenesis stages. Spitzer (1923) treats them as returns to one of the phylogenesis stages. Krimsky (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.
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 or transvaginal ultrasound.
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.
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 can affect the heart, typically resulting in the underdevelopment of the right ventricle or the left ventricle. This causes only one side of the heart to be capable of pumping blood to the body and lungs effectively. Hypoplasia of the heart is rare but is the most serious form of CHD. It is called hypoplastic left heart syndrome when it affects the left side of the heart and hypoplastic right heart syndrome when it affects the right side of the heart. In both conditions, the presence of a patent ductus arteriosus (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.
Obstruction 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, 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.
The septum is a wall of tissue which separates the left heart from the right heart. Defects in the interatrial septum or the interventricular septum allow blood to flow from the right side of the heart to the left, reducing the heart's efficiency. Ventricular septal defects are collectively the most common type of CHD, although approximately 30% of adults have a type of atrial septal defect called probe patent foramen ovale.
Cyanotic heart defects are called such because they result in cyanosis, a bluish-grey discoloration of the skin due to a lack of oxygen in the body. Such defects include persistent truncus arteriosus, total anomalous pulmonary venous connection, tetralogy of Fallot, transposition of the great vessels, and tricuspid atresia.
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.
Some constellations of multiple defects are commonly found together.
Most of the time CHD is serious and requires surgery and/or 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 patients 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.
Most patients 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.
Heart defects are among the most common birth defect, 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.
Congenital heart defects are known by a number of names including congenital heart anomaly, congenital heart disease, heart defects, and congenital cardiovascular malformations.
Absent pulmonary valve syndrome (also called congenital absence of the pulmonary valve) is a congenital heart defect that occurs when the flaps of the pulmonary valve do not develop or are severely underdeveloped (hypoplasia) resulting in aneurysms (dilation) of the pulmonary arteries and softening of the trachea and bronchi (tracheobronchomalacia). Usually, APVS occurs together with other congenital heart defects, most commonly ventricular septal defect and right ventricular outflow tract obstruction. It is sometimes considered a variant of Tetralogy of Fallot.Aortopulmonary window
Aortopulmonary window refers to a congenital heart defect similar in some ways to persistent truncus arteriosus. Persistent truncus arteriosus involves a single valve; aortopulmonary window is a septal defect.Atrial septostomy
Atrial septostomy is a surgical procedure in which a small hole is created between the upper two chambers of the heart, the atria. This procedure is primarily used to palliate dextro-Transposition of the great arteries or d-TGA (often imprecisely called transposition of the great arteries), a life-threatening cyanotic congenital heart defect seen in infants. It is performed prior to an arterial switch operation. Atrial septostomy has also seen limited use as a surgical treatment for pulmonary hypertension. One common technique was developed in 1966 by American cardiologist William Rashkind at the Children's Hospital of Philadelphia. The first atrial septectomy was developed by Vivien Thomas in a canine model and performed in humans by Alfred Blalock.
There are two types of this procedure: balloon atrial septostomy (also called endovascular atrial septostomy, Rashkind atrial balloon septostomy, or simply Rashkind's procedure) and blade atrial septostomy (also called static balloon atrial septostomy).Balloon septostomy
Balloon septostomy is the widening of a foramen ovale, patent foramen ovale (PFO), or atrial septal defect (ASD) via cardiac catheterization (heart cath) using a balloon catheter. This procedure allows a greater amount of oxygenated blood to enter the systemic circulation in some cases of cyanotic congenital heart defect (CHD).
After the catheter is inserted, the deflated balloon catheter is passed from the right atrium through the foramen ovale, PFO or ASD into the left atrium, it is then inflated and pulled back through to the right atrium, thereby enlarging the opening and allowing greater amounts of blood to pass through it. The resulting man-made opening is one of many forms of shunting, and is often referred to as an ASD.
This is normally a palliative procedure used to prepare a patient for, or sustain them until, a corrective surgery can be performed. At this time the ASD is closed using either sutures or a cardiac patch, depending on the size and/or nature of the opening. The procedure is often unsuccessful in infants and children older than one month because of a thickened septum.Crisscross heart
Crisscross heart is a type of congenital heart defect where the right atrium is closely associated with the left ventricle in space, and the left atrium is closely associated with the right ventricle.Although it is classified as a defect, the criss-cross is more of a spatial anomaly than a functional one, and it is possible for the heart to have relatively normal functioning. The ventricles are rotated either clockwise or counterclockwise resulting in the twisting of their connection. The actual blood flow stream through the ventricles is not interrupted.Cristian Dulca
Cristian Alexandru Dulca (born 25 October 1972 in Cluj) is a Romanian football coach and former player. Clubs he played for include CFR Cluj and Rapid Bucureşti. He was included in the Romania national football team squad for the 1998 FIFA World Cup. In 2003, he was forced to retire because of a congenital heart defect. In 2003, he became coach of Minerul Iara, the satellite team of Universitatea Cluj from Divizia C. In 2004, he was the coach of another Divizia C team, Avântul Reghin, during 13 matches. In February 2005, Dulca became executive director assistant at Universitatea Cluj.Cyanotic heart defect
Cyanotic heart defect is a group-type of congenital heart defect (CHD) that occurs due to deoxygenated blood bypassing the lungs and entering the systemic circulation or a mixture of oxygenated and unoxygenated blood entering the systemic circulation. It is caused by structural defects of the heart (i.e.: right-to-left, bidirectional shunting, malposition of the great arteries), or any condition which increases pulmonary vascular resistance. The result being the development of collateral circulation.Double inlet left ventricle
A double inlet left ventricle (DILV) or "single ventricle", is a congenital heart defect appearing in 5 in 100,000 newborns, where both the left atrium and the right atrium feed into the left ventricle. The right ventricle is hypoplastic or does not exist.Ebstein's anomaly
Ebstein's anomaly is a congenital heart defect in which the septal and posterior leaflets of the tricuspid valve are displaced towards the apex of the right ventricle of the heart. It's classified as a critical congenital heart defect accounting for <1% of all congenital heart defects presenting in ≈1 per 200,000 live births.Heart septal defect
Heart septal defect refers to a congenital heart defect of one of the septa of the heart.
Atrial septal defect
Atrioventricular septal defect
Ventricular septal defectAlthough aortopulmonary septal defects are defects of the aorticopulmonary septum, which is not technically part of the heart, they are sometimes grouped with the heart septal defects.Kurt Amplatz
Dr. Kurt Amplatz (born February 25, 1924) is an Austrian radiologist and medical device inventor. He is best known for the invention of the Amplatzer Septal Occluder as well as the Amplatzer Cribriform Occluder, which is used for closing atrial septal defect, a common congenital heart defect found in infants. These devices are inserted by percutaneous catheter placement, thus avoiding open heart surgery. In 1958, he performed one of the first percutaneous catheterizations of the heart.
Amplatz spent most of his 40-year career in Radiology as the Chairman of Interventional Radiology at the University of Minnesota.Levo-Transposition of the great arteries
Levo-Transposition of the great arteries (L-Transposition of the great arteries), also commonly referred to as congenitally corrected transposition of the great arteries (CC-TGA), is an acyanotic congenital heart defect (CHD) in which the primary arteries (the aorta and the pulmonary artery) are transposed, with the aorta anterior and to the left of the pulmonary artery; the morphological left and right ventricles with their corresponding atrioventricular valves are also transposed.
Use of the term "corrected" has been disputed by many due to the frequent occurrence of other abnormalities and or acquired disorders in l-TGA patients.
In segmental analysis, this condition is described as atrioventricular discordance (ventricular inversion) with ventriculoarterial discordance.l-TGA is often referred to simply as transposition of the great arteries (TGA); however, TGA is a more general term which may also refer to dextro-transposition of the great arteries (d-TGA).Mustard procedure
The Mustard procedure was developed in 1963 by Dr. William Mustard at the Hospital for Sick Children in Toronto, Ontario, Canada.
Dr. Mustard, with support from the Heart and Stroke Foundation of Canada, developed an alternative and simplified technique to the Senning procedure which was used to correct a congenital heart defect that produced “blue babies”. The technique was adopted by other surgeons and became the standard operation for d-TGA.In his autobiography, South African cardiac surgeon Christiaan Barnard claims to have been the first to perform the operation, with Mustard only following 'several years later'.Ostium primum atrial septal defect
The ostium primum atrial septal defect (also known as an endocardial cushion defect) is a defect in the atrial septum at the level of the tricuspid and mitral valves. This is sometimes known as an endocardial cushion defect because it often involves the endocardial cushion, which is the portion of the heart where the atrial septum meets the ventricular septum and the mitral valve meets the tricuspid valve.
Endocardial cushion defects are associated with abnormalities of the atrioventricular valves (the mitral valve and the tricuspid valve). These include the cleft mitral valve, and the single atrioventricular valve (a single large, deformed valve that flows into both the right ventricle and the left ventricle).
Endocardial cushion defects are the most common congenital heart defect that is associated with Down's syndrome.Overriding aorta
An overriding aorta is a congenital heart defect where the aorta is positioned directly over a ventricular septal defect (VSD), instead of over the left ventricle. The result is that the aorta receives some blood from the right ventricle, causing mixing of oxygenated and deoxygenated blood, and thereby reducing the amount of oxygen delivered to the tissues.
It is one of the four findings in the classic tetralogy of Fallot. The other three findings are right ventricular outflow tract (RVOT) obstruction (most often subpulmonary stenosis), right ventricular hypertrophy (RVH), and ventricular septal defect (VSD).Scimitar syndrome
Scimitar syndrome, or congenital pulmonary venolobar syndrome, is a rare congenital heart defect characterized by anomalous venous return from the right lung (to the systemic venous drainage, rather than directly to the left atrium). This anomalous pulmonary venous return can be either partial (PAPVR) or total (TAPVR). The syndrome associated with PAPVR is more commonly known as Scimitar syndrome after the curvilinear pattern created on a chest radiograph by the pulmonary veins that drain to the inferior vena cava. This radiographic density often has the shape of a scimitar, a type of curved sword. The syndrome was first described by Catherine Neill in 1960.Taussig–Bing syndrome
Taussig–Bing syndrome (after Helen B. Taussig and Richard Bing) is a cyanotic congenital heart defect in which the patient has both double outlet right ventricle (DORV) and subpulmonic ventricular septal defect (VSD).In DORV, instead of the normal situation where blood from the left ventricle (LV) flows out to the aorta and blood from the right ventricle (RV) flows out to the pulmonary artery, both aorta and pulmonary artery are connected to the RV, and the only path for blood from the LV is across the VSD. When the VSD is subpulmonic (sitting just below the pulmonary artery), the LV blood then flows preferentially to the pulmonary artery. Then the RV blood, by default, flows mainly to the aorta.
The clinical manifestations of a Taussig-Bing anomaly, therefore, are much like those of dextro-Transposition of the great arteries (but the surgical repair is different). It can be corrected surgically also with the arterial switch operation (ASO).
It is managed with Rastelli procedure.Timmy Lenox
Timmy Lenox is a fictional character from the NBC/DirecTV daytime drama Passions portrayed by Josh Ryan Evans. In a tragically ironic twist of fate, the actor died of a congenital heart defect the very day his character Timmy died on the show and donated his heart to Charity Standish.Ventricular outflow tract obstruction
A ventricular outflow tract obstruction is one type of congenital heart defect in which either the right or left ventricular outflow tract is blocked or obstructed. These obstructions represent a spectrum of disorders.