Heart Defects and Conditions

A congenital heart defect (CHD) is a defect in the structure of the heart and great vessels which is present at birth. Many types of heart defects exist, most of which either obstruct blood flow in the heart or vessels near it, or cause blood to flow through the heart in an abnormal pattern. Other defects, such as long QT syndrome, affect the heart’s rhythm.

Heart defects are among the most common birth defects and are the leading cause of birth defect-related deaths. Causes for congenital heart defects can be genetic, environmental, or both.
Many heart defects do have signs and symptoms. A doctor may not even detect signs of a heart defect during a physical exam. Symptoms depend on the number, type, and severity of the defects. Severe defects can cause signs and symptoms, usually in newborns. These signs and symptoms may include:

• Cyanosis (a bluish tint to the skin, lips, and fingernails)
• Rapid breathing
• Fatigue (tiredness)
• Sweating while feeding
• Not gaining weight (failure to thrive)
• Poor blood circulation

Older children who have congenital heart defects may get tired easily or short of breath during physical activity.

Many types of congenital heart defects cause the heart to work harder than it should. In severe defects, this can lead to heart failure. Heart failure is a condition in which the heart can’t pump enough blood to meet the body’s needs. Symptoms of heart failure include:

• Fatigue with physical activity
• Shortness of breath
• A buildup of blood and fluid in the lungs
• A buildup of fluid in the feet, ankles, and legs

To read more about medications that may be prescribed to your CHD baby, click here. To read more about the different types of surgeries for certain CHD’s, click here. To read more about what to expect during your CHD Baby’s open heart surgery, click here.

There are over 35 different types of CHD and each one is different. Some heart defects may not require any treatment at all, while others require only medication. Some require one surgery and some require multiple surgeries. Below is a partial list and general explanation of some CHD’s.

Aortic Stenosis (AS) – narrowing of the aortic valve or the vessel above the aortic valve. This reduces oxygenated blood flow to the body and overworks the left ventricle. Some abnormalities to the left ventricle may occur depending on the degree of aortic stenosis. There are a few surgical options depending on the severity of the defect.

• Valvar Aortic Stenosis – is a spectrum with significant valve obstruction treated in infancy or childhood. The other end of the spectrum is mild stenosis or commonly just a bicuspid aortic valve. As aortic stenosis can be progressive, even mild stenosis should be followed regularly until adulthood. Similarly, a bicuspid valve which may remain non-stenotic for decades, only to calcify and develop severe stenosis in the 6th to 7th decade of life. Symptoms of severe stenosis may include angina, labored breathing in response to exertion, or fainting (syncope).For infants, the most common treatment of valvar aortic stenosis is a balloon valvuloplasty, in which the narrowed aortic value is expanded by the inflation of a balloon. However, this technique is not a permanent fix as the narrowing may return with further growth. Also, the valvuloplasty technique is not effective in adults whose aortic valve leaflets have become calcified. One limiting factor to the success of balloon valvuloplasty is the careful balance between improving the opening of the valve without over-dilating the valve. Over-dilation of the valve can result in severe insufficiency. Nonetheless, balloon or surgical valvotomy (incision to improve the opening of the valve) always results in some degree of valve insufficiency. Moderate aortic insufficiency is poorly tolerated by the left ventricle and will likely result in aortic valve replacement.If the balloon valvuloplasty is not feasible, then a valvotomy will often be performed. This involves the surgical widening of the valve opening. In adult patients, however, calcification of the valve may make a valve replacement operation necessary. Even for patients who are treated with the valvotomy only, an aortic valve replacement will eventually become necessary because of calcification or valve regurgitation. The new valve may be expected to last for many years, depending on the age of the patient and the type of valve used, but it will eventually require replacement.
• Discrete Subvalvar Aortic Stenosis (DSVAS) – a fibrous ridge obstructs the outflow tract from the left ventricle into the aorta. This ridge may gradually become more prominent, leading to significant obstruction. Often, the subvalvular ridge may remain relatively small with only mild obstruction. However, because of its proximity to the aortic valve, it can often result in the development of aortic insufficiency. When aortic insufficiency develops most cardiologists recommend surgical removal of the sub-valvular stenosis in order to halt any further progression of the aortic insufficiency. Most commonly, however, late-developing DSVAS is recognized because of a heart murmur before symptoms are recognized.Unlike valvar aortic stenosis, DSVAS is not successfully treated with the balloon valvuloplasty. Instead, surgical resection or removal of the fibrous tissue is performed. In as many as 50% of cases, there will be some re-growth of the obstruction after surgery, so careful monitoring of the patient is necessary and the need for re-operation is relatively common as the ridge has been demonstrated to return.
• Supravalvar Aortic Valve – In this form of aortic stenosis, an hour glass-like narrowing or, less frequently, a more irregular narrowing, exist in the aorta above the aortic valve. Some forms of this defect are associated with Williams Syndrome, a hereditary disorder involving mild mental retardation and a tendency for the development of pulmonary and other arterial stenoses, as well as other features.In many cases, the subvalvar stenosis is moderate and stable and no surgical treatment is necessary. If the narrowing is more serious, surgery may be performed to widen the aorta, with special care not to damage the aortic valve.Because of the possibility of progressive obstruction, patients with this defect should be closely monitored through life. Also, there may be a tendency for the narrowing of other vessels, such as the renal and coronary arteries, especially in the adult.

Atrial Septal Defect (ASD) – a hole in the septum between the upper left and upper right heart chambers. This causes mixing of the red and blue blood, thus overworking the right side of the heart. The three types of ASD’s are Sinus Venosus, Ostium Primum and Ostium Secundum. Sometimes the ASD can be closed during a cardiac catheterization or surgery may be required.

Atrioventricular Canal Defect (AV Canal Defect) – a hole located between the two sides of the heart. The hole is usually located where the wall between the upper atrial chambers joins the wall between the lower ventricular chambers. The result is an ASD and VSD. The tricuspid and mitral valves are also abnormal, in that there is one large common valve. This defect is also referred to as Endocardial Cushion Defect or Atrioventricular Septal Defect. Surgery is required to close the ASD and VSD and rebuild the mitral and tricuspid valves.

Bicuspid Aortic Valve (BAV) – a defect of the aortic valve that results in the formation of two leaflets or cusps instead of the normal three. Normally only the mitral valve (bicuspid valve) has two cusps (instead of three). The aortic valve is situated between the left atrium and left ventricle. About 1-2% of the population have bicuspid aortic valves, although the condition is nearly twice as common in males. It is more common than any other congenital cardiac anomaly. In many cases, the condition will cause no problems. However, especially later in life, a bicuspid aortic valve may become calcified, which may lead to varying degrees of severity of aortic stenosis and aortic regurgitation, which will manifest as murmurs. If these become severe enough, they may require heart surgery.

Cardiomyopathy

The term “cardiomyopathy” refers to a diseased state of the heart involving abnormalities of the muscle fibers, which contract with each heartbeat. It is considered a primary problem when it occurs because the muscle cells themselves are abnormal (usually due to a gene mutation). It is a secondary problem when the muscle cells were normal but are affected by other diseases that have secondary damaging effects on the heart and its function such as certain infections, low blood flow to the heart, low blood oxygen or high blood pressure. According to the Pediatric Cardiomyopathy Registry, one in every 100,000 children in the U.S. under the age of 18 is diagnosed with cardiomyopathy. The majority of diagnosed children are under 12 months followed by children 12 to 18 years old. Because the clinical features and therapies differ, it is best to separate this disease into four broad types:

• Dilated Cardiomyopathy (DCM)
  Dilated or congestive cardiomyopathy is diagnosed when the heart is enlarged (dilated) and the pumping chambers contract poorly (usually left side worse than right). For more detailed info, click here.
• Hypertrophic Cardiomyopathy (HCM)
  Most often diagnosed during infancy or adolescence, hypertrophic cardiomyopathy is the second most common form of heart muscle disease, is usually genetically transmitted, and comprises about 35–40% of cardiomyopathies in children. For more detailed info, click here.
• Restrictive Cardiomyopathy (RCM)
  Restrictive cardiomyopathy is a rare form of heart muscle disease that is characterized by restrictive filling of the ventricles. In this disease, the contractile function (squeeze) of the heart and wall thicknesses are usually normal, but the relaxation or filling phase of the heart is very abnormal. For more detailed info, click here.
• Miscellaneous (Rare) Cardiomyopathies – There are other forms of cardiomyopathy which comprise only a very small percentage of the total (2–3%) number of cardiomyopathies in children. These cardiomyopathies may have overlapping features with any of the previous types described and include arrhythmogenic right ventricular dysplasia (ARVD), mitochondrial and left ventricular non-compaction cardiomyopathies (LVNC). For more detailed info on ARVD, click here. For more detailed info on LVNC, click here.

For info on a rare form of cardiomyopathy called Danon Disease, click here.

Coarctation of the Aorta (COA) – narrowing in the aorta between the aortic arch and the descending aorta, resulting in decreased blood flow to the body and more work for the heart. Sometimes this can be fixed during a cardiac catheterization or surgery may be required.

Congenitally Corrected Transposition of the Great Arteries – is a complex and unusual abnormality occurring in fewer than 1 percent of people with congenital heart disease. It occurs in males twice as often as females. The condition is actually a combination of two heart abnormalities that cancel each other out, resulting in a condition in which the circulation of blood through the body is “correct.” The position of the two ventricles is reversed so that the right atrium connects to the left ventricle and the left atrium connects to the right ventricle. The two great arteries (the aorta and pulmonary artery) therefore arise from the wrong ventricle. In other words, the aorta arises from the right ventricle and sends blood around the body and the pulmonary artery arises from the left ventricle and takes blood to the lungs. You will note, however, that with this arrangement, while the blood is flowing through the wrong ventricles, it is still going in the correct direction, hence the term “congenitally corrected transposition”. Read more here.

Dextrocardia – refers to the heart being situated on the right side of the body. Dextrocardia Situs Inversus refers to the heart being a mirror image situated on the right side. For all visceral organs to be mirrored, the correct term is Dextrocardia Situs Inversus Totalis.

DiGeorge Syndrome – is a syndrome caused by the deletion of a small piece of chromosome 22. The deletion occurs near the middle of the chromosome at a location designated q11.2 i.e., on the long arm of one of the pair of chromosomes 22.

The features of this syndrome vary widely, even among members of the same family, and affect many parts of the body. Characteristic signs and symptoms may include birth defects such as congenital heart disease, defects in the palate, most commonly related to neuromuscular problems with closure (velo-pharyngeal insufficiency), learning disabilities, mild differences in facial features, and recurrent infections. Infections are common in children due to problems with the immune system’s T-cell mediated response that in some patients is due to an absent or hypoplastic thymus. 22q11.2 deletion syndrome may be first spotted when an affected newborn has heart defects or convulsions from hypocalcemia due to malfunctioning the parathyroid glands and low levels of parathyroid hormone (parathormone). Affected individuals may also have any other kind of birth defect including kidney abnormalities and significant feeding difficulties as babies. Autoimmune disorders such as hypothyroidism and hypoparathyroidism or thrombocytopenia (low platelet levels), and psychiatric illnesses are common late-occurring features.

Double Aortic Arch (DAA) -is a relatively rare congenital cardiovascular malformation. DAA is an anomaly of the aortic arch in which two aortic arches form a complete vascular ring that can compress the trachea and/or esophagus. Most commonly there is a larger (dominant) right arch behind and a smaller (hypoplastic) left aortic arch in front of the trachea/esophagus. The two arches join to form the descending aorta which is usually on the left side (but maybe right-sided or in the midline). In some cases the end of the smaller left aortic arch closes (left atreti arch) and the vascular tissue becomes a fibrous cord. Although in these cases a complete ring of two patent aortic arches is not present, the term ‘vascular ring’ is the accepted generic term even in these anomalies.

Double Inlet Right Ventricle (DILV) – a tricuspid valve that leads into the left ventricle instead of the right, leaving the right ventricle small and underdeveloped. A VSD is also present with this defect. This defect is also referred to as Single Ventricle. This CHD is usually treated with surgery. Surgical options may include the Damus-Kaye-Stansel Procedure, the Fontan Procedure, and the Norwood procedure. The goal is separating the pulmonary and the systemic circulation.

Double Outlet Right Ventricle (DORV) – a complex defect where the aorta and pulmonary arteries both arise from the right ventricle (the aorta normally arises from the left ventricle). A large VSD is usually present, which serves as an outlet for blood from the left ventricle. While the relationship of the aorta and pulmonary artery plus the position of the VSD vary greatly with the different forms of DORV, they are crucial in diagnosis and treatment. These are the different types of DORV:

• DORV with subaortic VSD is when a ventricular septal defect (VSD) occurs directly beneath the aorta. This is the most common type of DORV, accounting for 60%-70% of all DORV cases. In this defect, blood from the left ventricle is primarily directed into the aorta. If pulmonic stenosis (a narrowed pulmonic valve and/or narrowing of the muscular region below the pulmonary valve, restricting blood flow to the lungs) is also present, there will likely be the same symptoms as Tetralogy of Fallot. This condition is generally treated when the person is about 6 months old.
• DORV with subpulmonary VSD or Taussig-Bing is when a VSD occurs directly beneath the pulmonary artery, meaning that blood from the left ventricle is generally directed into the pulmonary artery. Patients with this condition show the same symptoms as those who have Transposition of the Great Arteries. This condition is generally treated at birth or as soon as the diagnosis is established. This type of DORV is rare, accounting for 8%-10% of all DORV cases.
• DORV with doubly committed VSD is when a VSD occurs in equal proximity to both great vessels, thus the blood from the left ventricle may be more equally committed to either the aorta or the pulmonary artery. The symptoms of this condition and the ideal age for treatment vary widely from person to person.
• DORV with non-committed VSD is when a VSD occurs far away from the great vessels. Symptoms of this condition vary widely. This condition is generally treated between ages 3 to 5 years.

Ebstein’s Anomaly – a malformation and displacement of the tricuspid valve into the right ventricle. An ASD is sometimes present with this defect. While there is free flow of blood forward across the tricuspid valve to the right ventricle, the deformed tricuspid valve allows a large amount of blood to flow backwards from the right ventricle to right atrium when the right ventricle contracts. Surgery may be required and the repair may involve a Blalock-Taussig shunt or a repair to the tricuspid valve and right ventricle.

Eisenmenger’s Complex – results when an unrepaired VSD causes high blood pressure in the lungs, which reverses the blood flow back through the hole (VSD), making the child “blue”. It is usually an irreversible problem.

Endocardial Fibroelastosis – is a rare heart disorder that affects infants and children. It is characterized by an abnormal thickening of heart tissue, especially around the valves, causing abnormal enlargement of the heart (cardiac hypertrophy), especially affecting the left ventricle. Impaired heart and lung function can eventually lead to congestive heart failure. It can cause valve failure and sudden death. Endocardial Fibroelastosis may occur for no apparent reason (sporadic) or may be inherited as an X-linked or autosomal recessive genetic trait.

Heart Block – when the heart’s electrical impulses cannot pass from the upper to lower chambers properly. It can be congenital or acquired by disease or injury to the electrical conduction system during surgery. Pacemakers are usually needed.

Hypoplastic Left Heart Syndrome (HLHS) – a condition where the left side of the heart is underdeveloped, typically the left ventricle. The left atrium, mitral valve, aortic valve and aorta can also be affected. There are two main options to correct HLHS – one is heart transplantation and the other is a three-stage surgery. The first stage is the Norwood, done soon after birth (sometimes all three stages are considered as “The Norwood”). The second stage is the Glenn, which is usually done between 4 months and six months of age. The third stage is the Fontan, which is usually done before the child enters kindergarden. Most patients who get through the three stages do quite well. They are able to lead a fairly normal life with few restrictions. Most patients have to be on some kind of anticoagulant (like baby aspirin), many need Digoxin, Lasix or some other kind of diuretic (at least for some time post-operatively) and/or medications to control blood pressure. Of course they have to take antibiotics prophylactically, as do other children with severe, congenital heart defects.

Hypoplastic Right Heart Syndrome (HRHS) – a condition where the right side of the heart is underdeveloped, typically the right ventricle. Pulmonary atresia and/or tricuspid atresia are also present with this defect. There are two main options to correct HRHS – one is a “one-and-a-half ventricle repair” and the other is a three-stage surgery. The first stage is a Blalock-Taussig shunt, done soon after birth. The second is the Glenn, which is usually done between 4 months and 6 months of age. The third is the Fontan, which is usually done before the child enters kindergarden.

Interrupted Aortic Arch – absence of a portion of the aorta and aortic arch. Surgery is needed to join the segments together directly or with a conduit.

Kawasaki Disease – an acquired heart disease which is characterized by fever, rash, and swelling of the lymph nodes and other areas. Long term heart complications can also develop, including damage to the coronary arteries and the heart muscle itself.

Long QT Syndrome – is an abnormality of the heart’s electrical system. The mechanical function of the heart is entirely normal. The electrical problem is due to defects in heart muscle cell structures called ion channels. It is a rare congenital heart condition with delayed repolarization following depolarization (excitation) of the heart, associated with syncope (fainting) due to ventricular arrhythmias, possibly of lethal type (torsade de pointes), which can deteriorate into ventricular fibrillation and ultimately sudden death. Arrhythmia in individuals with LQTS is often associated with exercise or excitement.

Mitral Valve Abnormalities – the Mitral Valve is on the left side of the heart, between the left atrium and left ventricle. The left atrium receives oxygenated blood from the lungs. Blood passes through the mitral valve to the left ventricle to be pumped out to the body.

• Mitral Valve Stenosis is narrowing of the mitral valve, restricting blood flow to the left ventricle and causing blood to back up into the left atrium. This causes the left atrium to enlarge and further backup of blood in the lungs, which may cause difficulty breathing and increased lung pressure, called pulmonary hypertension. Without surgery to repair or replace the valve, the right side of the heart may also become enlarged trying to pump blood to the already saturated lungs.
• Mitral Valve Regurgitation (insufficiency) is when the mitral valve does not close well and blood leaks back into the left atrium. This causes the left atrium to enlarge. This may lead to arrhythmias. Depending on the severity of this defect, this may be treated with medication. If Mitral Valve Regurgitation does not respond well to medication, surgery to repair or replace the valve is necessary.
• Mitral Valve Prolapse is when one of the two leaflets on the mitral valve extends back into the left atrium (prolapses), instead of stopping even with its attachment to the annulus of the valve. This is a very common defect occurring in an estimated 5% of the population. Usually treatment is not required.

Myocardial Bridge – A myocardial bridge is a band of heart muscle that lies on top of a coronary artery, instead of underneath it. With a myocardial bridge, part of a coronary artery dips into and underneath the heart muscle and then comes back out again. The band of muscle that lies on top of the coronary artery is called a “bridge,” and this is how the condition gets its name.

In most patients, a myocardial bridge is not treated if it is not causing any symptoms. In patients with symptoms, medicines such as beta-blockers and calcium channel blockers are usually the first line of treatment. In rare cases, patients need surgery to relieve their symptoms. Surgery involves removing the bridge that is pressing on the coronary artery.

Partial Anomalous Pulmonary Vein Return (PAPVR) – one or more (but not all) of the pulmonary veins return blood to someplace other than the left atrium – usually to the right atrium, inferior vena cava or superior vena cava. An ASD is sometimes present with this defect. Surgery is needed to detach the anomalous pulmonary vein and reconnect to the left atrium.

Patent Ductus Arteriosis (PDA) – failure of the ductus arteriosus to close shortly after birth, causing the blood that should go out to the body to return to the lungs. This can be corrected in a cardiac catheterization or in surgery.

Pulmonary Arterial Hypertension (PAH) – occurs when there is high blood pressure in the lungs which can lead to heart failure. PAH can be idiopathic (unexplained) or it can be secondary to another condition, such as a congenital heart defect, chronic lung disease, autoimmune disease, liver disease, etc. There are various degrees of PAH, which are usually measured during a catheterization. Treatment depends of the severity.

Pulmonary Atresia – the absence of a pulmonary valve or a defective pulmonary artery resulting in lack of blood flow to the lungs. Often the right ventricle is also underdeveloped and sometimes a VSD is present with this defect. The only source of lung blood flow is the patent ductus arteriosus (PDA), an open passageway between the pulmonary artery and the aorta. If the PDA narrows or closes, the lung blood flow is reduced to critically low levels. This can cause very severe cyanosis. Early treatment often includes using a drug to keep the PDA from closing. Usually the first surgery is a Blalock-Taussig shunt. Further surgeries can include the Glenn and/or Fontan, or replacing the pulmonary valve and artery above it. If there is no VSD, then the right ventricle becomes Hypoplastic. The surgeries needed would be the same as those needed in a HRHS defect.

Pulmonary Valve Stenosis (PS) – is narrowing of the pulmonary valve. It is a valvular heart disease in which outflow of blood from the right ventricle of the heart is obstructed at the level of the pulmonic valve. This results in the reduction of blood flow to the lungs. Valvular pulmonic stenosis accounts for 80% of right ventricular outflow tract obstruction. While the most common cause of pulmonary valve stenosis is congenital heart disease, it may also be due to rheumatic heart disease or a malignant carcinoid tumor. With pulmonary stenosis, problems with the pulmonary valve make it harder for the leaflets to open and permit blood to flow forward from the right ventricle to the lungs. In children, these problems can include a valve that only has one or two leaflets instead of three, a valve that has leaflets that are partially fused together or a valve that has thick leaflets that do not open all the way. Depending on the severity of the pulmonary stenosis, open heart surgery may be needed to correct the defect. Another option may be a balloon valvuloplasty. This procedure is done in the cardiac catheterization lab.

Rheumatic Heart Disease (RHD) – an acquired heart disease where the heart valves are damaged by a process that begins with strep throat. If not treated, strep can develop into rheumatic fever, an inflammatory disease that affects the connective tissues of the body, including the heart. /p>

Sick Sinus Syndrome – occurs when the heart’s sinus node (where electrical impulses start) does not operate properly, resulting in a slow heart rate (bradycardia) and/or rapid heart rate (tachycardia). Treatment options include medication and/or a pacemaker.

Subaortic Valve Stenosis – narrowing of the left ventricle just below the aortic valve, causing a limitation of blood flow out of the left ventricle. Treatment may include medication or surgery to remove the constriction.

Tetralogy of Fallot (TOF) – combination of four defects – Pulmonary Stenosis, VSD, Overriding Aorta and Right Ventricular Hypertrophy, resulting in blue blood being blocked when trying to get from the right ventricle to the lungs. Surgical options include an aorta to pulmonary artery shunt, usually done shortly after birth, with a second surgery at 4 months to 6 months of age to completely repair the defect by closing the VSD and fixing the pulmonary valve and/or artery.

Total Anomalous Pulmonary Venous Connection (TAPVR) – a condition where none of the pulmonary veins return blood from the lungs to the left atrium as they should. Instead, they come together to form a common vein that attaches directly or indirectly to the right atrium. An ASD is usually present. Surgery is required to reconnect the pulmonary veins so that blood flows to the left atrium. This anomaly is categorized in 3 different types:

1. Type A – Supracardiac TAPVR is an anomaly in which the pulmonary veins attach behind the heart through the superior vena cava. In this anomaly the blood has to drain upwards into the right atrium.
2. Type B – Cardiac TAPVR is an anomaly where the pulmonary veins come together behind the heart through a vein called the coronary sinus, where the blood then drains into the right atrium.
3. Type C – Infracardiac TAPVR is an anomaly where the pulmonary veins come together behind the heart through the hepatic veins, and the inferior vena cava.

Transposition of the Great Arteries (TGA) – a condition where the aorta and pulmonary arteries are reversed; the aorta is incorrectly attached to the right ventricle and the pulmonary artery is incorrectly attached to the left ventricle, resulting in parallel blood flow instead of a figure eight blood flow seen normally. Often there is some mixing of blood due to an ASD, VSD, patent ductus arteriosus or other defect. The surgery recommended is called the Arterial Switch to detach the great arteries and reattach them to the correct positions.

Tricuspid Atresia – lack of formation of the tricuspid valve, resulting in no blood flow between the right atrium and the right ventricle. This leads to a hypoplastic or an absence of the right ventricle. Because of the lack of an A-V connection, an atrial septal defect (ASD) must be present to maintain blood flow. Also, since there is a lack of a right ventricle there must be a way to pump blood into the pulmonary arteries, and this is accomplished by a ventricular septal defect (VSD). Other defects may also be present, such as pulmonary stenosis or transposition of the great arteries. A three-stage surgery is usually performed – Blalock-Taussig shunt, Glenn Shunt and the Fontan.

Truncus Arteriosus – a condition where the normally seperate aorta and pulmonary artery share a single large vessel instead of two seperate ones. There is often a single valve at the base (truncus) and a large VSD. There are four different types of truncus arteriosus, depending on where the pulmonary arteries come off the aorta. Surgery is usually required.

Uhl Anomaly – is a very rare CHD (less than 100 cases 1900–1993) with a partial or total loss of the myocardial muscle in the right ventricle. Three findings include enlarged right ventricular cavity without apical trabeculation and with a thin hypokinetic ventricular wall.

Ventricular Inversion – also known as atrioventricular discordance, is a condition in which the anatomic right ventricle of the heart is on the left side of the interventricular septum and the anatomic left ventricle is on the right.

Ventricular Septal Defect (VSD) – a hole in the septum of the lower left and lower right heart chambers. This allows blue blood to mix with red blood, causing the heart to be overworked and possibly enlarged. A small hole may not need to be closed, a medium-sized hole may be closed during a cardiac catheterization and a larger hole may require surgery.

Wolff-Parkinson-White Syndrome (WPW) – is a syndrome of pre-excitation of the ventricles of the heart due to an accessory pathway known as the bundle of Kent. This accessory pathway is an abnormal electrical communication from the atria to the ventricles. The incidence of WPW syndrome is between 0.9 and 3% of the general population. While the vast majority of individuals with a bundle of Kent remain asymptomatic throughout their entire lives, there is a risk of sudden death associated with the syndrome. Sudden death due to WPW syndrome is rare (incidence of less than 0.6%), and is due to the effect of the accessory pathway on tachyarrhythmias in these individuals.

• ventricular septal defect (VSD)
• atrial septal defect (ASD)
• patent ductus arteriosus (PDA)
• atrioventricular canal (AV canal or AVC)

• tricuspid atresia (TA)
• pulmonary atresia (PA)
• transposition of the great arteries (TGA)
• tetralogy of fallot (TOF)

• coarctation of the aorta
• aortic stenosis
• pulmonary stenosis

• hypoplastic left heart syndrome (HLHS)
• truncus arteriosis
• total anomalous pulmonary venous return (TAPVR)