Without life-prolonging interventions, HLHS is fatal, but with intervention, an infant may survive. A cardiothoracic surgeon may perform a series of operations or a full heart transplant. While surgical intervention has emerged as the standard of care in the United States, other national health systems, notably in France, approach diagnosis of HLHS in a more conservative manner, with an emphasis on termination of pregnancy or compassionate care after delivery.

Before surgery, the ductus must be kept open to allow blood-flow using medication containing prostaglandin. Air with less oxygen than normal is used for infants with hypoplastic left heart syndrome. These low oxygen levels increases the pulmonary vascular resistance (PVR) and thus improve blood flow to the rest of the body, due to the greater pressure difference between the lungs and body. Achieving oxygen levels below atmosphere requires the use of inhaled nitrogen. Nitric oxide is a potent pulmonary vasodilator, and thus reduces PVR and improves venous return. Any factor that increases PVR will impede right sided flow.

To treat Lutembacher's syndrome, the underlying causes of the disorder must first be treated: mitral stenosis and atrial septal defect. Lutembacher's syndrome is usually treated surgically with treatments such as:

- percutaneous transcatheter therapy for MS

- Device closure of ASD

Percutaneous transcatheter treatment for the MS can include transcatheter therapies of such as balloon valuloplasty.

Treatment is with neonatal surgical repair, with the objective of restoring a normal pattern of blood flow. The surgery is open heart, and the patient will be placed on cardiopulmonary bypass to allow the surgeon to work on a still heart. The heart is opened and the ventricular septal defect is closed with a patch. The pulmonary arteries are then detached from the common artery (truncus arteriosus) and connected to the right ventricle using a tube (a conduit or tunnel). The common artery, now separated from the pulmonary circulation, functions as the aorta with the truncal valve operating as the aortic valve. Most babies survive this surgical repair, but may require further surgery as they grow up. For example, the conduit does not grow with the child and may need to be replaced as the child grows. Furthermore, the truncal valve is often abnormal and may require future surgery to improve its function.

There have been cases where the condition has been diagnosed at birth and surgical intervention is an option. A number of these cases have survived well into adulthood.

Treatment is surgical and involves closure of the atrial and ventricular septal defects and restoration of a competent left AV valve as far as is possible. Open surgical procedures require a heart-lung machine and are done with a median sternotomy. Surgical mortality for uncomplicated ostium primum defects in experienced centers is 2%; for uncomplicated cases of complete atrioventricular canal, 4% or less. Certain complications such as tetralogy of Fallot or highly unbalanced flow across the common AV valve can increase risk significantly.

Infants born with AVSD are generally in sufficient health to not require immediate corrective surgery. If surgery is not required immediately after birth, the newborn will be closely monitored for the next several months, and the operation held-off until the first signs of lung distress or heart failure. This gives the infant time to grow, increasing the size of, and thereby the ease of operation on, the heart, as well as the ease of recovery. Infants will generally require surgery within three to six months, however, they may be able to go up to two years before the operation becomes necessary, depending on the severity of the defect.

Palliative treatment is normally administered prior to corrective surgery in order to reduce the symptoms of d-TGA (and any other complications), giving the newborn or infant a better chance of surviving the surgery. Treatment may include any combination of:

Percutaneous transcatheter therapy is used to repair the mitral valve and sometimes the septum. In percutaneous balloon mitral valvuloplasty, using a catheter, a ballon such as the Inoue ballon is placed into blood vessels in the groin area and the balloon guided to the heart. If a hole is not already present, a small hole may need to be inserted the atria and inserted into the mitral valve through the left atrium; the balloon is then inflated. The balloon inside the mitral valve will be inflated and deflated several times to wide the valve opening until the opening is satisfactory; the balloon will then be deflated and removed.

The advantage to using percutaneous procedures instead of open-heart surgery is not needing general anesthesia, blood transfusions, and the recovery time is quicker. The drawback to this procedure is the lack of repeating and transseptal procedures if they are needed later. Also if the patient later develops a relapse of MS, surgery will need to be performed where using more evasive techniques. Additionally, if a hole is needed to be inserted into the atria to obtain access to the mitral valve, there is a risk of developing ASD secondarily.

The treatment of pulmonary atresia consists of: an IV medication called prostaglandin E1, which is used for treatment of pulmonary atresia, as it stops the ductus arteriosus from closing, allowing mixing of the pulmonary and systemic circulations, but prostaglandin E1 can be dangerous as it can cause apnea. Another example of preliminary treatment is heart catheterization to evaluate the defect or defects of the heart; this procedure is much more invasive. Ultimately, however, the individual will need to have a series of surgeries to improve the blood flow permanently. The first surgery will likely be performed shortly after birth. A shunt can be created between the aorta and the pulmonary artery to help increase blood flow to the lungs. As the child grows, so does the heart and the shunt may need to be revised in order to meet the body's requirements.

The type of surgery recommended depends on the size of the right ventricle and the pulmonary artery, if the right ventricle is small and unable to act as a pump, the surgery performed would be the Fontan procedure. In this three-stage procedure, the right atrium is disconnected from the pulmonary circulation. The systemic venous return goes directly to the lungs, by-passing the heart.Very young children with elevated pulmonary vascular resistance may not able to undergo the Fontan procedure. Cardiac catheterization may be done to determine the resistance before going ahead with the surgery.

Tet spells may be treated with beta-blockers such as propranolol, but acute episodes require rapid intervention with morphine or intranasal fentanyl to reduce ventilatory drive, a vasopressor such as phenylephrine, or norepinephrine to increase systemic vascular resistance, and IV fluids for volume expansion.

Oxygen (100%) may be effective in treating spells because it is a potent pulmonary vasodilator and systemic vasoconstrictor. This allows more blood flow to the lungs by decreasing shunting of deoxygenated blood from the right to left ventricle through the VSD. There are also simple procedures such as squatting and the knee chest position which increase systemic vascular resistance and decrease right-to-left shunting of deoxygenated blood into the systemic circulation.

When PGE is administered to a newborn, it prevents the ductus arteriosus from closing, therefore providing an additional shunt through which to provide the systemic circulation with a higher level of oxygen.

Antibiotics may be administered preventatively. However, due to the physical strain caused by uncorrected d-TGA, as well as the potential for introduction of bacteria via arterial and central lines, infection is not uncommon in pre-operative patients.

Diuretics aid in flushing excess fluid from the body, thereby easing strain on the heart.

Analgesics normally are not used pre-operatively, but they may be used in certain cases. They are occasionally used partially for their sedative effects.

Cardiac glycosides are used to maintain proper heart rhythm while increasing the strength of each contraction.

Sedatives may be used palliatively to prevent a young child from thrashing about or pulling out any of their lines.

Sometimes CHD improves without treatment. Other defects are so small that they do not require any treatment. 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.

Surgical operations to assist with hypoplastic left heart are complex and need to be individualized for each patient. A cardiologist must assess all medical and surgical options on a case-by-case basis.

Currently, infants undergo either the staged reconstructive surgery (Norwood or Sano procedure within a few days of birth, Glenn or "Hemi-Fontan procedure" at 3 to 6 months of age, and the Fontan procedure at 1 1/2 to 5 years of age) or cardiac transplantation. Current expectations are that 70% of those with HLHS will reach adulthood. Many studies show that the higher the volume (number of surgeries performed) at a hospital, the lower the mortality (death) rate. Factors that increase an infant's risk include lower birth weight, additional congenital anomalies, a genetic syndrome or those with a highly restrictive atrial septum.) For patients without these additional risk factors, 5 year survival now approaches 80%. Further, studies show that about 50% of those children who survived surgery in the early development of staged reconstruction have developmental delay or need special education; about 25% of these surgical survivors have severe disabilities. There is growing evidence that while the incidence of developmental and behavioral disabilities continues to be higher than that in the general population, children operated upon in the more current era have shown significantly better neurological outcomes. An alternative to the traditional Norwood is the Hybrid procedure.

Some physicians offer "compassionate care", instead of the surgeries, which results in the child's death, usually within 2 weeks of birth. Compassionate care is overseen by a physician, and may be carried out either in the hospital or at home. However, due to the vast improvement of surgical intervention, with many hospitals achieving over 90% survival, there is debate on whether or not "compassionate care" should still be offered to families. A study in 2003 concluded that a selection of physicians who are experts in the care of children with HLHS were evenly split when asked what they would do if their own children were born with HLHS, with 1/3 stating that they would choose surgery, 1/3 stating that they would choose palliative (compassionate) treatment without surgery, and 1/3 stating that they are uncertain which choice they would make.

The three-stage procedure is a palliative procedure (not a cure), as the child's circulation is made to work with only two of the heart's four chambers.

The Blalock-Thomas-Taussig procedure, initially the only surgical treatment available for tetralogy of Fallot, was palliative but not curative. The first total repair of tetralogy of Fallot was done by a team led by C. Walton Lillehei at the University of Minnesota in 1954 on an 11-year-old boy. Total repair on infants has had success from 1981, with research indicating that it has a comparatively low mortality rate.

Total repair of tetralogy of Fallot initially carried a high mortality risk, but this risk has gone down steadily over the years. Surgery is now often carried out in infants one year of age or younger with less than 5% perioperative mortality. The open-heart surgery is designed to relieve the right ventricular outflow tract stenosis by careful resection of muscle and to repair the VSD with a Gore-Tex patch or a homograft.> Additional reparative or reconstructive surgery may be done on patients as required by their particular cardiac anatomy.

The Canadian Cardiovascular Society (CCS) recommends surgical intervention for these indications:

- Limited exercise capacity (NYHA III-IV)

- Increasing heart size (cardiothoracic ratio greater than 65%)

- Important cyanosis (resting oxygen saturation less than 90% - level B)

- Severe tricuspid regurgitation with symptoms

- Transient ischemic attack or stroke

The CCS further recommends patients who require operation for Ebstein's anomaly should be operated on by congenital heart surgeons who have substantial specific experience and success with this operation. Every effort should be made to preserve the native tricuspid valve.

A device, known as the Amplatzer muscular VSD occluder, may be used to close certain VSDs. It was initially approved in 2009. It appears to work well and be safe. The cost is also lower than having open heart surgery. The device is placed through a small incision in the groin.

The Amplatzer septal occluder was shown to have full closure of the ventricular defect within the 24 hours of placement. It has a low risk of embolism after implantation. Some tricuspid valve regurgitation was shown after the procedure that could possibly be due from the right ventricular disc. There have been some reports that the Amplatzer septal occluder may cause life-threatening erosion of the tissue inside the heart. This occurs in one percent of people implanted with the device and requires immediate open-heart surgery. This erosion occurs due to improper sizing of the device resulting with it being too large for the defect, causing rubbing of the septal tissue and erosion.

Ebstein's cardiophysiology typically presents as an (antidromic) AV reentrant tachycardia with associated pre-excitation. In this setting, the preferred medication treatment agent is procainamide. Since AV-blockade may promote conduction over the accessory pathway, drugs such as beta blockers, calcium channel blockers, and digoxin are contraindicated.

If atrial fibrillation with pre-excitation occurs, treatment options include procainamide, flecainide, propafenone, dofetilide, and ibutilide, since these medications slow conduction in the accessory pathway causing the tachycardia and should be administered before considering electrical cardioversion. Intravenous amiodarone may also convert atrial fibrillation and/or slow the ventricular response.

Surgical closure of an ASD involves opening up at least one atrium and closing the defect with a patch under direct visualization.

Percutaneous device closure involves the passage of a catheter into the heart through the femoral vein guided by fluoroscopy and echocardiography. An example of a percutaneous device is a device which has discs that can expand to a variety of diameters at the end of the catheter. The catheter is placed in the right femoral vein and guided into the right atrium. The catheter is guided through the atrial septal wall and one disc (left atrial) is opened and pulled into place. Once this occurs, the other disc (right atrial) is opened in place and the device is inserted into the septal wall. This type of PFO closure is more effective than drug or other medical therapies for decreasing the risk of future thromboembolism.

Percutaneous closure of an ASD is currently only indicated for the closure of secundum ASDs with a sufficient rim of tissue around the septal defect so that the closure device does not impinge upon the superior vena cava, inferior vena cava, or the tricuspid or mitral valves. The Amplatzer Septal Occluder (ASO) is commonly used to close ASDs. The ASO consists of two self-expandable round discs connected to each other with a 4-mm waist, made up of 0.004– to 0.005-inch Nitinol wire mesh filled with Dacron fabric. Implantation of the device is relatively easy. The prevalence of residual defect is low. The disadvantages are a thick profile of the device and concern related to a large amount of nitinol (a nickel-titanium compound) in the device and consequent potential for nickel toxicity.

Percutaneous closure is the method of choice in most centres.

Simple l-TGA has a very good prognosis, with many individuals being asymptomatic and not requiring surgical correction.

In a number of cases, the (technically challenging) "double switch operation" has been successfully performed to restore the normal blood flow through the ventricles.

a) Surgical closure of a Perimembranous VSD is performed on cardiopulmonary bypass with ischemic arrest. Patients are usually cooled to 28 degrees. Percutaneous Device closure of these defects is rarely performed in the United States because of the reported incidence of both early and late onset complete heart block after device closure, presumably secondary to device trauma to the AV node.

b) Surgical exposure is achieved through the right atrium. The tricuspid valve septal leaflet is retracted or incised to expose the defect margins.

c) Several patch materials are available, including native pericardium, bovine pericardium, PTFE (Gore-Tex or Impra), or Dacron.

d) Suture techniques include horizontal pledgeted mattress sutures, and running polypropylene suture.

e) Critical attention is necessary to avoid injury to the conduction system located on the left ventricular side of the interventricular septum near the papillary muscle of the conus.

f) Care is taken to avoid injury to the aortic valve with sutures.

g) Once the repair is complete, the heart is extensively deaired by venting blood through the aortic cardioplegia site, and by infusing Carbon Dioxide into the operative field to displace air.

h) Intraoperative transesophageal echocardiography is used to confirm secure closure of the VSD, normal function of the aortic and tricuspid valves, good ventricular function, and the elimination of all air from the left side of the heart.

i) The sternum, fascia and skin are closed, with potential placement of a local anesthetic infusion catheter under the fascia, to enhance postoperative pain control.

j) Multiple muscular VSDs are a challenge to close, achieving a complete closure can be aided by the use of fluorescein dye.

There is no cure for hypoplastic right heart syndrome. A three-stage surgical procedure is commonly used to treat the condition. The surgeries rearrange the blood flow within the heart and allow the left ventricles to do the work for the underdeveloped right side of the heart. The three surgeries are spread out over the patients first few years of life. The first procedure, called the Norwood procedure, is typically done within the first few days or weeks of life. The second procedure, called the Glenn procedure, is usually performed between four and twelve months of age. The last surgery, known as the Fontan procedure, is typically performed between the ages of 18 months and three years. These surgeries change the blood flow to the lungs so that there is always oxygenated blood. The surgeries are a temporary fix from 15–30 years in which a patient will have to have a heart transplant.[3]

In a stage 1 Norwood procedure for hypoplastic right heart, the main pulmonary artery is separated from the left and right portions of the pulmonary artery and joined with the upper portion of the aorta.[7] The proximal pulmonary artery is connected to the hypoplastic aortic arch, while the narrowed segment of the aorta is repaired. An aortopulmonary shunt is created to connect the aorta to the main pulmonary artery to provide pulmonary blood flow to the lungs.[7] The Glen procedure disconnects the superior vena cava from the heart and connects it to the right pulmonary artery so deoxygenated blood from the upper body goes directly to the lungs.[10] The Fontan procedure done usually after the patient is two years old, disconnects the inferior vena cava from the heart and connects it directly with the other pulmonary artery so that deoxygenated blood from the lower body then is sent directly to the lungs.[1]

Treatment consists of open heart surgery soon after birth. Awaiting surgery, prostaglandin can be administered to keep the ductus arteriosus open, thereby allowing blood flow to the lower body. Failure to treat the condition yields a mortality rate of 90% at a median age of 4 days.

For newborns with transposition, prostaglandins can be given to keep the ductus arteriosus open which allows mixing of the otherwise isolated pulmonary and systemic circuits. Thus oxygenated blood that recirculates back to the lungs can mix with blood that circulates throughout the body. The arterial switch operation is the definitive treatment for dextro- transposition. Rarely the arterial switch is not feasible due to particular coronary artery anatomy and an atrial switch operation is preferred.

When there are holes in the septum that divide the four chambers of the heart the oxygen-rich blood and oxygen-poor blood mix this creates more stress on the heart to pump blood to where oxygen is needed. As a result, you get enlargement of the heart, heart failure (being unable to adequately supply body with needed oxygen, pulmonary hypertension, and pneumonia.

The development of pulmonary hypertension is very serious. And this because the left ventricle is weakened due to its overuse. When this happens, the pressure backs up into the pulmonary veins and the lungs. This type of damage is irreversible which is why immediate treatment is recommended after diagnosis.

The prognosis for pulmonary atresia varies for every child, if the condition is left uncorrected it may be fatal, but the prognosis has greatly improved over the years for those with pulmonary atresia. Some factors that affect how well the child does include how well the heart is beating, and the condition of the blood vessels that supply the heart. Most cases of pulmonary atresia can be helped with surgery, if the patient's right ventricle is exceptionally small, many surgeries will be needed in order to help stimulate normal circulation of blood to the heart.If uncorrected, babies with this type of congenital heart disease may only survive for the first few days of life. Many children with pulmonary atresia will go on to lead normal lives, though complications such as endocarditis, stroke and seizures are possible.

With a series of operations or even a heart transplant, a newborn can be treated but not be cured. Young individuals who have undergone reconstructive surgery must refer to a cardiologist who is experienced in congenital heart diseases, "Children with HLHS are at an increased level for developing endocarditis." Kids that have been diagnosed with HRHS must limit the physical activity they participate in to their own endurance level.