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.

Treatment is not necessary in asymptomatic patients.

The treatment options for mitral stenosis include medical management, mitral valve replacement by surgery, and percutaneous mitral valvuloplasty by balloon catheter.

The indication for invasive treatment with either a mitral valve replacement or valvuloplasty is NYHA functional class III or IV symptoms.

Another option is balloon dilatation. To determine which patients would benefit from percutaneous balloon mitral valvuloplasty, a scoring system has been developed. Scoring is based on 4 echocardiographic criteria: leaflet mobility, leaflet thickening, subvalvar thickening, and calcification. Individuals with a score of ≥ 8 tended to have suboptimal results. Superb results with valvotomy are seen in individuals with a crisp opening snap, score < 8, and no calcium in the commissures.

Treatment also focuses on concomitant conditions often seen in mitral stenosis:

- Any angina is treated with short-acting nitrovasodilators, beta-blockers and/or calcium blockers

- Any hypertension is treated aggressively, but caution must be taken in administering beta-blockers

- Any heart failure is treated with digoxin, diuretics, nitrovasodilators and, if not contraindicated, cautious inpatient administration of ACE inhibitors

The effect of statins on the progression of AS is unclear. The latest trials do not show any benefit in slowing AS progression, but did demonstrate a decrease in ischemic cardiovascular events.

In general, medical therapy has relatively poor efficacy in treating aortic stenosis. However, it may be useful to manage commonly coexisting conditions that correlate with aortic stenosis:

- Any angina is generally treated with beta-blockers and/or calcium blockers. Nitrates are contraindicated due to their potential to cause profound hypotension in aortic stenosis.

- Any hypertension is treated aggressively, but caution must be taken in administering beta-blockers.

- Any heart failure is generally treated with digoxin and diuretics, and, if not contraindicated, cautious administration of ACE inhibitors.

While observational studies demonstrated an association between lowered cholesterol with statins and decreased progression, a randomized clinical trial published in 2005 failed to find any effect on calcific aortic stenosis. A 2007 study did demonstrate a slowing of aortic stenosis with the statin rosuvastatin.

In terms of treatment for pulmonary valve stenosis, valve replacement or surgical repair (depending upon whether the stenosis is in the valve or vessel) may be indicated. If the valve stenosis is of congenital origin, balloon valvuloplasty is another option, depending on the case.

Valves made from animal or human tissue (are used for valve replacement), in adults metal valves can be used.

Acute decompensated heart failure due to AS may be temporarily managed by an intra-aortic balloon pump while pending surgery. In those with high blood pressure nitroprusside may be carefully used. Phenylephrine may be used in those with very low blood pressure.

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.

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 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.

Each of the symptoms of situs ambiguous must be managed with appropriate treatment dependent upon the organ system involved. Intestinal malrotation is treated surgically using the Ladd procedure. This procedure widens a fold in the peritoneum so that the intestines can be placed in non-rotated formation. Unfortunately, it is not possible to return the bowel to a normal morphology However, 89% of patients that undergo the Ladd surgery experience a complete resolution of symptoms.

Following cholangiogram, a Kasai Procedure is usually performed in cases of biliary atresia. In this surgery, a Y-shaped shunt is used to passage bile from the liver directly to the intestine. If this is unsuccessful, liver transplantation can be considered based on the overall health of the patient. Fortunately, the Kasai Procedure is successful in approximately 80% of patients. Following the operation, patients are advised to take fat-soluble vitamins, choleretics, and anti-inflammatory medications.

Functionally asplenic patients have an elevated lifetime risk of septicemia, as they have no functional spleen for fighting infection. For this reason, asplenic patients are under constant observation for any signs of fever or infection. In the case of infection, patients are placed on controlled empiric antibiotic therapy to avoid development of antibiotic resistance. This therapy battles infection by both gram-positive and gram-negative bacteria.

Right-atrial and left-atrial isomerism and associated pulmonary issues are treated in a series of steps based on the severity of symptoms. Isomeric patients are first treated by inserting a shunt that will move incoming blood through the pulmonary circuit. The Fontan procedure routes blood through the patient's single ventricle, to the lungs, and into systemic circulation. This process is favorable in patients aged 2 – 5 years old. Unfortunately, 20-30% of patients will require a heart transplant. Left-atrial isomeric patients have less severe complications, as they typically have 2 functional ventricles. In this case, they can undergo biventricular repair to form 2 separate ventricles and functional associated valves.

Prognosis for patients with situs ambiguous is quite varied, considering the spectrum of clinical complications. Infants who experience severe cyanosis at birth die within hours of delivery if medical intervention is not immediate. Alternatively, longevity of neonates with mild cardiac lesions is unaffected. Ten percent of patients born with right atrial isomerism die by the age of 5 without intervention. Fortunately, improvements in therapies has increased the 5-year survival to 30-74% for right atrial isomeric patients and 65-84% for left atrial isomeric patients based on the cause of their disease.

Mitral valvuloplasty is a minimally invasive therapeutic procedure to correct an uncomplicated mitral stenosis by dilating the valve using a balloon.

Under local anaesthetic, a catheter with a special balloon is passed from the right femoral vein, up the inferior vena cava and into the right atrium. The interatrial septum is punctured and the catheter passed into the left atrium using a "trans-septal technique." The balloon is sub-divided into 3 segments and is dilated in 3 stages. First, the distal portion (lying in the left ventricle) is inflated and pulled against the valve cusps. Second, the proximal portion is dilated, in order to fix the centre segment at the valve orifice. Finally, the central section is inflated, this should take no longer than 30 seconds, since full inflation obstructs the valve and causes congestion, leading to circulatory arrest and flash pulmonary edema.

With careful patient pre-selection, percutaneous balloon mitral valvuloplasty (PBMV) is associated with good success rates and a low rate of complications. By far the most serious adverse event is the occurrence of acute severe mitral regurgitation. Severe mitral regurgitation usually results from a tear in one of the valve leaflets or the subvalvular apparatus. It can lead to pulmonary edema and hemodynamic compromise, necessitating urgent surgical mitral valve replacement.

Other serious complications with PBMV usually relate to the technique of trans-septal puncture (TSP). The ideal site for TSP is the region of the fossa ovalis in the inter-atrial septum. Occasionally, however, the sharp needle used for TSP may inadvertently traumatize other cardiac structures, leading to cardiac tamponade or serious blood loss.

Although the immediate results of PBMV are often quite gratifying, the procedure does not provide permanent relief from mitral stenosis. Regular follow-up is mandatory, to detect restenosis. Long-term follow-up data from patients undergoing PBMV indicates that up to 70-75% individuals can be free of restenosis 10 years following the procedure. The number falls to about 40% 15 years post-PBMV.

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]

Head circumference measurements should be obtained regularly and monitored carefully to detect hydrocephalus. Neurosurgical procedures to relieve hydrocephalus are important. A ventriculoperitoneal shunt may be required in some infants. A pediatric cardiologist should be consulted to manage high-output failure, if present. Often patients need to be intubated. In most cases, the fistulous arteries feeding into the Vein of Galen must be blocked, thereby reducing the blood flow into the vein. Open surgery has a high morbidity and mortality. Recent advances over the past few decades have made endovascular embolization the preferred method of treatment. These treatments are preferred because they offer little threat to the surrounding brain tissue. However, there have been several reported cases of arteriovenous malformations recurring. The young age of many patients, the complex vascular anatomy, and the sensitive location of the Vein of Galen offer considerable challenges to surgeons. Another treatment option is Radiotherapy. Radiotherapy, also called radiosurgery, involves the use of focused beams to damage the blood vessel. Radiotherapy is often not pursued as a treatment because the effects of the procedure can take months or years and there is risk of damaging adjacent brain tissue.

Surgery is not always an option when the anatomy of the malformation creates too much of a risk. Recent improvements in endovascular procedures have made many cases, which were not surgically accessible, treatable. Endovascular treatments involve delivering drugs, balloons, or coils to the site of the malformation through blood vessels via catheters. These treatments work by limiting blood flow through the vein. There is, however, still risk of complications from endovascular treatments. The wall of the vein can be damaged during the procedure and, in some cases, the emboli can become dislodged and travel through the vascular system. Two-dimensional echocardiography with color-flow imaging and pulsed Doppler ultrasound was used to evaluate one fetus and five neonates with a Vein of Galen malformation. Color-flow imaging and pulsed Doppler ultrasonography provided anatomical and pathophysiological information regarding cardiac hemodynamics and intracranial blood flow; with the patient's clinical status, these methods provided a reliable, noninvasive means to evaluate the effectiveness of therapy and the need for further treatment in neonates with Vein of Galen malformations. When none of these procedures are viable, shunting can be used to ameliorate the pressure inside the varix. Seizures usually are managed with antiepileptic medications.

It is sometimes treated with surgery, which involves rerouting blood from the right atrium into the left atrium with a patch or use of the Warden procedure. However, interest is increasing in catheter-based interventional approaches, as well as medical therapy for less severe cases.

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.

In TAPVC without obstruction, surgical redirection can be performed within the first month of life. The operation is performed under general anesthesia. The four pulmonary veins are reconnected to the left atrium, and any associated heart defects such as atrial septal defect, ventricular septal defect, patent foramen ovale, and/or patent ductus arteriosus are surgically closed. With obstruction, surgery should be undertaken emergently. PGE1 should be given because a patent ductus arteriosus allows oxygenated blood to go from the circulation of the right heart to the systemic circulation.

The treatment of choice is percutaneous balloon valvuloplasty and is done when a resting peak gradient is seen to be >60mm Hg or a mean >40mm Hg is observed.

No medical therapy has been found to be effective at decreasing the growth rate or rupture rate of asymptomatic AAAs. Blood pressure and lipids should, however, be treated per usual.

The treatment options for asymptomatic AAA are management, surveillance with a view to eventual repair, and immediate repair. Two modes of repair are available for an AAA: open aneurysm repair, and endovascular aneurysm repair (EVAR). An intervention is often recommended if the aneurysm grows more than 1 cm per year or it is bigger than 5.5 cm. Repair is also indicated for symptomatic aneurysms.

Several methods of treatment are available, mainly consisting of careful drug therapy and surgery. Glucocorticoids (such as prednisone or methylprednisolone) decrease the inflammatory response to tumor invasion and edema surrounding the tumor. Glucocorticoids are most helpful if the tumor is steroid-responsive, such as lymphomas. In addition, diuretics (such as furosemide) are used to reduce venous return to the heart which relieves the increased pressure.

In an acute setting, endovascular stenting by an interventional radiologist may provide relief of symptoms in as little as 12–24 hours with minimal risks.

Should a patient require assistance with respiration whether it be by bag/valve/mask, BiPAP, CPAP or mechanical ventilation, extreme care should be taken. Increased airway pressure will tend to further compress an already compromised SVC and reduce venous return and in turn cardiac output and cerebral and coronary blood flow. Spontaneous respiration should be allowed during endotracheal intubation until sedation allows placement of an ET tube and reduced airway pressures should be employed when possible.

The following table includes the main types of valvular stenosis and regurgitation. Major types of valvular heart disease not included in the table include mitral valve prolapse, rheumatic heart disease and endocarditis.

The evaluation of individuals with valvular heart disease who are or wish to become pregnant is a difficult issue. Issues that have to be addressed include the risks during pregnancy to the mother and the developing fetus by the presence of maternal valvular heart disease as an intercurrent disease in pregnancy.

Normal physiological changes during pregnancy require, on average, a 50% increase in circulating blood volume that is accompanied by an increase in cardiac output that usually peaks between the midportion of the second and third trimesters. The increased cardiac output is due to an increase in the stroke volume, and a small increase in heart rate, averaging 10 to 20 beats per minute. Additionally uterine circulation and endogenous hormones cause systemic vascular resistance to decrease and a disproportionately lowering of diastolic blood pressure causes a wide pulse pressure. Inferior vena caval obstruction from a gravid uterus in the supine position can result in an abrupt decrease in cardiac preload, which leads to hypotension with weakness and lightheadedness. During labor and delivery cardiac output increases more in part due to the associated anxiety and pain, as well as due to uterine contractions which will cause an increases in systolic and diastolic blood pressure.

Valvular heart lesions associated with high maternal and fetal risk during pregnancy include:

1. Severe aortic stenosis with or without symptoms

2. Aortic regurgitation with NYHA functional class III-IV symptoms

3. Mitral stenosis with NYHA functional class II-IV symptoms

4. Mitral regurgitation with NYHA functional class III-IV symptoms

5. Aortic and/or mitral valve disease resulting in severe pulmonary hypertension (pulmonary pressure greater than 75% of systemic pressures)

6. Aortic and/or mitral valve disease with severe LV dysfunction (EF less than 0.40)

7. Mechanical prosthetic valve requiring anticoagulation

8. Marfan syndrome with or without aortic regurgitation

In individuals who require an artificial heart valve, consideration must be made for deterioration of the valve over time (for bioprosthetic valves) versus the risks of blood clotting in pregnancy with mechanical valves with the resultant need of drugs in pregnancy in the form of anticoagulation.

Pulmonary valve stenosis (PVS) is a heart valve disorder in which outflow of blood from the right ventricle of the heart is obstructed at the level of the pulmonic valve. This type of pulmonic stenosis results in the reduction of flow of blood 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 a malignant carcinoid tumor. Both stenosis of the pulmonary artery and pulmonary valve stenosis are forms of pulmonic stenosis (nonvalvular and valvular, respectively). PVS was the key finding that led Jacqueline Noonan to identify the syndrome now called Noonan syndrome.

Although its cause is poorly understood, situs ambiguous has been linked to family history of malformations and maternal cocaine use, suggesting both genetic and environmental factors play a role. Several genes in the TGF-beta pathway, which controls left-right patterning of viseral organs across the body axis, have been indicated in sporadic and familial cases of atrial isomerism.

There does not appear to be a screening method for prevention of heterotaxy syndrome. However, genetic testing in family members that display atrial isomerism or other cardiac malformations may help to discern risk for additional family members, especially in X-linked causes of heterotaxy syndrome.