AUTHOR AND EDITOR INFORMATION

Section 1 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

INTRODUCTION

Section 2 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Background

Hypoplastic left heart syndrome (HLHS) describes a spectrum of cardiac abnormalities characterized by marked hypoplasia of the left ventricle and ascending aorta. The aortic and mitral valves are atretic, hypoplastic, or stenotic. The ventricular septum is usually intact. A large patent ductus arteriosus supplies blood to the systemic circulation. Systemic desaturation may be present because of complete mixing of pulmonary and systemic venous blood in the right atrium via an atrial septal defect or patent foramen ovale. Coarctation of the aorta commonly coexists.

Hypoplastic left heart syndrome is a uniformly lethal cardiac abnormality if not surgically corrected. In 1979, Norwood performed the first successful surgical palliation on a neonate. Currently, this approach consists of a series of 3 operations: the Norwood procedure (stage I), the hemi-Fontan or bidirectional Glenn procedure (stage II), and the Fontan procedure (stage III). Orthotopic heart transplantation provides an alternative therapy, with results similar to those of the staged surgical palliation. Currently, the survival rate of infants treated with these surgical approaches is similar to that of infants with other complex forms of congenital heart disease in which a 2-ventricle repair is not possible.

Pathophysiology

The newborn infant with hypoplastic left heart syndrome has a complex cardiovascular physiology. Fully saturated pulmonary venous blood returning to the left atrium cannot flow into the left ventricle because of atresia, hypoplasia, or stenosis of the mitral valve. Therefore, pulmonary venous blood must cross the atrial septum and mix with desaturated systemic venous blood in the right atrium. The right ventricle then must pump this mixed blood to both the pulmonary and the systemic circulations that are connected in parallel, rather than in series, by the ductus arteriosus. Blood exiting the right ventricle may flow (1) to the lungs via the branch pulmonary arteries or (2) to the body via the ductus arteriosus and descending aorta. The amount of blood that flows into each circulation is based on the resistance in each circuit.

Blood flow is inversely proportional to resistance (Ohm law); that is, when resistance in blood vessels decreases, blood flow through these vessels increases. Following birth, pulmonary vascular resistance decreases, which allows a higher percentage of the fixed right ventricular output to go to the lungs instead of the body. Although increased pulmonary blood flow results in higher oxygen saturation, systemic blood flow is decreased. Perfusion becomes poor, and metabolic acidosis and oliguria may develop. Coronary artery and cerebral perfusion also are dependent on systemic blood flow through the ductus arteriosus. Therefore, increased pulmonary blood flow results in decreased flow to the coronary arteries and brain, with a risk of myocardial or cerebral ischemia.

Alternatively, if pulmonary vascular resistance is significantly higher than systemic vascular resistance, systemic blood flow is increased at the expense of pulmonary blood flow. This may result in profound hypoxemia. A careful delicate balance between pulmonary and systemic vascular resistance ensures adequate oxygenation and tissue perfusion.

Most patients with hypoplastic left heart syndrome also demonstrate coarctation of the aorta. This can be significant enough to interfere with retrograde flow to the proximal aorta.

Frequency

United States

Incidence of hypoplastic left heart syndrome is 0.16-0.36 per 1000 live births. Hypoplastic left heart syndrome accounts for 7-9% of all congenital heart disease diagnosed in the first year of life. Before surgical treatment was available, hypoplastic left heart syndrome was responsible for 25% of cardiac deaths in the neonatal period. The rate of occurrence is increased in patients with Turner, Noonan, Smith-Lemli-Opitz, or Holt-Oram syndrome. Certain chromosomal duplications, translocations, and deletions also are associated with hypoplastic left heart syndrome.

International

Frequency is similar to that in the United States.

Mortality/Morbidity

• Without surgery, hypoplastic left heart syndrome is uniformly fatal usually within the first 2 weeks of life. Survival for a longer period occurs rarely and only with persistence of the ductus arteriosus.
• Following the Norwood procedure (stage I), overall success (survival to hospital discharge) is approximately 75%. Success rates are higher (85%) in patients with low preoperative risk and lower (45%) in patients with important risk factors. Some centers have reported stage I survival rates in excess of 90%. This appears to be related, in part, to institutional surgical volume. The overall success following the hemi-Fontan procedure (stage II) approaches 95%. Success after completing the Fontan procedure (stage III) approaches 90%. Orthotopic heart transplantation results in early and long-term success similar to that of staged reconstruction. Among low-risk patients who undergo staged reconstruction or transplantation, actuarial survival at 5 years is approximately 70%.
• Most studies report neurodevelopmental disabilities in a significant number of patients who survive either staged surgical reconstruction or cardiac transplantation.

Sex

Hypoplastic left heart syndrome is more common in males than in females, with a 55-70% male predominance.

Age

Hypoplastic left heart syndrome typically presents within the first 24-48 hours of life. Presentation occurs as soon as the ductus arteriosus constricts, thereby decreasing systemic blood flow, producing shock, and, without intervention, causing death. Infants with pulmonary venous obstruction (absent or restrictive patent foramen ovale) may present sooner. Very rarely, an infant with persistence of high pulmonary vascular resistance and the ductus arteriosus may present later because of balanced pulmonary and systemic blood flow.

CLINICAL

Section 3 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

History

• Although hypoplastic left heart syndrome can easily be detected on fetal echocardiography, many infants are not identified prenatally because routine obstetric ultrasound examination may not concentrate on cardiac anatomy. Pregnancies are typically uncomplicated, and fetal echocardiography is not indicated routinely. The fetus grows and develops normally because the fetal circulation is not altered significantly. Most neonates are born at term and initially appear normal.
• Occasionally, respiratory symptoms and profound systemic cyanosis are apparent at birth (2-5% of cases). In these infants, significant obstruction to pulmonary venous return (a congenitally small or absent patent foramen ovale) is usually present.
• As the ductus arteriosus begins to close normally over the first 24-48 hours of life, symptoms of cyanosis, tachypnea, respiratory distress, pallor, lethargy, metabolic acidosis, and oliguria develop. Without intervention to reopen the ductus arteriosus, death rapidly ensues.

Physical

• Before the initiation of prostaglandin E1 infusion to reestablish patency of the ductus arteriosus, infants exhibit signs of cardiogenic shock, including the following:
• • Hypothermia
  • Tachycardia
  • Respiratory distress
  • Central cyanosis and pallor
  • Poor peripheral perfusion with weak pulses in all extremities and in the neck
  • Hepatomegaly
• After reestablishment of systemic blood flow via the ductus arteriosus, signs of shock resolve, leaving the stable infant with tachycardia, tachypnea, and mild central cyanosis. If a coarctation of the aorta is present, arterial pulses in the legs may be more prominent than those in the arms, particularly the right arm.
• Cardiac examination
• • Palpable right ventricular impulse
  • Normal first heart sound
  • Loud single second heart sound
  • Nonspecific, soft, systolic ejection murmur at the left sternal border (not always present)
  • High-pitched holosystolic murmur at the lower left sternal border, indicating tricuspid regurgitation (not always present)
  • Diastolic flow rumble over the precordium, indicating increased right ventricular diastolic filling (not always present)

Causes

• The exact cause of hypoplastic left heart syndrome is unknown. Most likely, the primary abnormality occurs during aortic and mitral valve development. During cardiac development, adequate flow of blood through a structure is largely responsible for the growth of that structure. With little or no blood flow because of aortic and mitral valve atresia, growth of the left ventricle does not occur.
• Similarly, growth of the ascending aorta does not occur because of lack of left ventricular output. The ascending aorta is perfused in retrograde manner from the ductus arteriosus functioning only as a common coronary artery.
• Premature closure or absence of the foramen ovale represents another theoretical cause of hypoplastic left heart syndrome, as it eliminates fetal blood flow from the inferior vena cava to the left atrium. Fetal pulmonary blood flow is not sufficient for normal development of the left atrium, left ventricle, and ascending aorta.

DIFFERENTIALS

Section 4 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Other Problems to be Considered

Associated cardiac abnormalities

Anomalous pulmonary venous connection
Coarctation of the aorta
Complete atrioventricular canal
Coronary artery abnormalities (especially in patients with aortic atresia and mitral stenosis)
Persistent left superior vena cava
Endocardial fibroelastosis (especially in patients with aortic atresia and mitral stenosis)

Associated noncardiac abnormalities

Genetic disorders

Significant noncardiac abnormalities

Central nervous system malformation
Diaphragmatic hernia
Necrotizing enterocolitis

WORKUP

Section 5 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Lab Studies

• Complete blood count
• • Measure hemoglobin levels, because severe neonatal anemia can cause high-output congestive heart failure (CHF) and cardiogenic shock. The hemoglobin level is usually normal.
  • Obtain a total white blood cell (WBC) count with differential. Sepsis can cause symptoms of shock. The WBC count is typically normal.
• Electrolytes
• • Electrolyte abnormalities may be present in infants with poor oral intake secondary to CHF. Use carbon dioxide to assess acid-base status.
  • Electrolyte levels are usually normal. The carbon dioxide level may be low if a metabolic acidosis is present.
• BUN/creatinine
• • Infants with critical illness and significantly reduced systemic perfusion may show evidence of renal failure.
  • The creatinine may be elevated transiently.
• Liver function tests
• • Infants with critical illness and significantly reduced systemic perfusion and CHF may show evidence of hepatocellular damage.
  • Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels may be elevated transiently.
• Arterial blood gases and lactic acid
• • Assessing acid-base status is paramount, especially to rule out metabolic acidosis. Most infants have some evidence of metabolic acidosis, which should be corrected immediately. Elevated levels of serum lactic acid generally precede a fall in pH, as acidosis develops.
  • Assessment of PaO₂ and PaCO₂ is important for respiratory management and manipulation of pulmonary vascular resistance by mechanical ventilation and the addition of supplemental inhaled nitrogen. The PaO₂ is optimally 30-45 mm Hg, and the PaCO₂ is ideally 45-50 mm Hg.
• Ultrasound of the head
• • An ultrasound of the head is necessary only if the infant has had a significantly long period in shock with potentially poor cerebral perfusion.
  • Most often, no abnormalities are observed on the ultrasound scan of the head.
• Karyotype
• • Chromosomal analysis is indicated for infants with dysmorphic features.
  • Nearly 25% of infants have chromosomal abnormalities.

Imaging Studies

• Chest radiograph
• • Chest radiographic findings are not specific for hypoplastic left heart syndrome.
  • Cardiomegaly and increased pulmonary venovascular markings are typically present.
  • Marked pulmonary edema may be noted in infants with obstructed pulmonary venous return.
• Echocardiogram
• • The echocardiogram is the test of choice for diagnosing hypoplastic left heart syndrome. Two-dimensional imaging clearly shows the hypoplastic left ventricle and ascending aorta. The right atrium, tricuspid valve, right ventricle, and main pulmonary artery are larger than usual.
  • Other structural abnormalities should be excluded.
  • Doppler and color Doppler imaging are also important.
  • Evaluate tricuspid regurgitation, a preoperative risk factor for the Norwood procedure, and blood flow across the atrial septum. Observe retrograde blood flow from the ductus arteriosus into the transverse aortic arch and ascending aorta.
  • Evaluate the aortic arch and thoracic aorta for evidence of coarctation.

Other Tests

• Electrocardiogram
• • The electrocardiogram typically shows sinus tachycardia, right-axis deviation, right atrial enlargement, and right ventricular hypertrophy with a qR configuration in the right precordial leads.
  • A paucity of left ventricular forces is noted in the left precordial leads.

Procedures

• Cardiac catheterization
• • Pre–Norwood procedure
    • Routine diagnostic catheterization is not necessary because 2-dimensional and Doppler echocardiography can provide the necessary anatomic and hemodynamic data.
    • Perform interventional catheterization with blade/balloon atrial septostomy to relieve pulmonary venous hypertension if blood flow from left atrium to right atrium is severely restricted at the atrial septum.
  • Pre–hemi-Fontan (stage II) procedure
    • Perform routine catheterization before the operation to obtain hemodynamic data and several important angiograms.
    • Calculate pulmonary vascular resistance to ensure the patient's suitability for the stage II procedure.
    • Perform an angiogram in the right ventricle to show ventricular function and tricuspid regurgitation.
    • Perform another angiogram in the transverse aortic arch near the shunt to show pulmonary artery size and distribution and to rule out recurrent aortic coarctation or significant aortopulmonary collateral vessels.
    • If collateral vessels are found, they may be occluded with coils at the same catheterization.
  • Pre-Fontan (stage III) procedure
    • Accomplish routine catheterization before completing the operation.
    • Calculate pulmonary vascular resistance and perform a right ventricular angiogram.
    • Delineate pulmonary artery anatomy by performing an angiogram at the superior vena cava–pulmonary artery anastomosis via an internal jugular approach.
    • Recurrent coarctation of the aorta and significant collateral vessels are excluded again.
  • Postcatheterization precautions include hemorrhage, vascular disruption after balloon dilation, pain, nausea and vomiting, and arterial or venous obstruction from thrombosis or spasm.

TREATMENT

Section 6 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Medical Care

• Successful preoperative management depends on providing adequate systemic blood flow while limiting pulmonary overcirculation.
• Open the ductus arteriosus
  • Blood flow to the systemic circulation (coronary arteries, brain, liver, kidneys) is dependent on flow through the ductus arteriosus. If a diagnosis is suspected, start prostaglandin E1 infusion immediately to establish ductal patency and ensure adequate systemic perfusion.
  • If the diagnosis is made prenatally or when the infant is relatively asymptomatic, a smaller dose of prostaglandin E1 may be sufficient to keep the ductus arteriosus patent while limiting its side effects.
  • A larger dose of prostaglandin E1 is often required to reopen the ductus arteriosus if an infant has cardiovascular collapse and shock due to ductal closure.
  • Ideally, prostaglandin E1 is administered centrally via an umbilical venous catheter.
• Correct metabolic acidosis
  • Metabolic acidosis indicates inadequate cardiac output to meet the metabolic demands of the body. Acidosis adversely affects the myocardium.
  • Correction of metabolic acidosis with sodium bicarbonate infusion is essential in early management. This therapy is futile if the ductus arteriosus remains constricted.
• Manipulate pulmonary vascular resistance
  • The pulmonary vascular resistance of a newborn is slightly less than the systemic vascular resistance and begins to fall soon after birth. In the patient with hypoplastic left heart syndrome, decreased pulmonary vascular resistance causes increased pulmonary blood flow and an undesirable obligatory decrease in systemic blood flow. Increased alveolar oxygen decreases pulmonary vascular resistance, leading to increased pulmonary blood flow. Therefore, most infants should remain in room air with acceptable oxygen saturation (pulse oximeter) in the low 70s. An exceptional circumstance would be in the infant with severe hypoxemia caused by pulmonary venous hypertension.
  • Achieving a slightly higher PaCO₂, in the range of 45-50 mm Hg, can increase pulmonary vascular resistance. This can be accomplished by intubation, sedation, mechanical hypoventilation, or the addition of nitrogen or carbon dioxide to the infant's inspired gas via the endotracheal tube or hood. It is preferable not to intubate these infants.
  • Serial blood gas analysis is necessary. Initially, an umbilical arterial catheter is useful to obtain frequent blood samples.
• Inotropes
  • Inotropic support is indicated only in severely ill neonates with concurrent sepsis or profound cardiogenic shock and acidosis.
  • The administration of inotropes can adversely affect the balance between pulmonary and systemic vascular resistance.
  • If needed, wean from inotropic support as soon as the infant is clinically stable.
• Diuretics
  • Consider diuretics to manage pulmonary overcirculation before surgery.
  • Agents commonly used include furosemide and spironolactone.
• Antibiotics
  • Antibiotics are indicated if the infant is at risk for antepartum infection.
  • Discontinue antibiotics after obtaining negative blood cultures.

Surgical Care

• The goal of surgical reconstruction is to eventually separate the pulmonary and systemic circulations by completing a Fontan operation. The right ventricle remains the systemic ventricle while blood flows to the lungs passively. This ultimate reconstruction is accomplished in 3 stages.
• • Norwood procedure (stage I)
    • This procedure is usually performed during the first weeks of life, after the infant has been stabilized in the neonatal intensive care unit (ICU). The goals of the procedure are (1) to establish reliable systemic circulation in the absence of the ductus arteriosus and (2) to provide enough pulmonary blood flow for adequate oxygenation, while simultaneously protecting the pulmonary vascular bed in preparation for stages II and III.
    • The Norwood procedure includes (1) performing an atrial septectomy to provide unrestricted blood flow across the atrial septum, (2) ligating the ductus arteriosus, (3) creating an anastomosis between the main pulmonary artery and the aorta to provide systemic blood flow, (4) eliminating coarctation of the aorta, and (5) placing an aorta–to–pulmonary artery shunt to provide pulmonary circulation.
    • At hospital discharge, most infants remain on digoxin to augment cardiac function, on diuretics to help manage right ventricular volume overload, and on aspirin to prevent thrombosis of the shunt. If tricuspid regurgitation is present, use afterload reduction with captopril. Oxygen saturation is typically 70-80% in room air.
  • Hemi-Fontan procedure (stage II)
    • The hemi-Fontan procedure is performed approximately 6 months after the Norwood procedure. Before surgery, perform a cardiac catheterization to assess right ventricular function, pulmonary artery anatomy, and pulmonary vascular resistance. If results are favorable, schedule elective surgery.
    • The hemi-Fontan procedure includes creating an anastomosis between the superior vena cava and the right pulmonary artery, so that venous return from the upper body can flow directly into both lungs. The superior vena cava–right atrial junction is closed with a patch that is removed during the next stage. Blood from the inferior vena cava continues to drain into the right atrium. The aorta–to–pulmonary artery shunt that was placed at stage I is ligated.
    • At discharge, infants usually remain on digoxin, diuretics, aspirin, and captopril for the reasons mentioned above.
  • Fontan procedure (stage III)
    • The Fontan procedure is done approximately 12 months after the hemi-Fontan procedure. Again, catheterization is necessary to ensure that the child is a candidate for surgery.
    • Completion of the Fontan procedure includes directing blood flow from the inferior vena cava to the pulmonary arteries by placing a tube within the right atrium. At the conclusion of the procedure, systemic venous blood returns to the lungs passively without passing through a ventricle.
    • At discharge, most children remain on digoxin, diuretics, aspirin, and captopril if necessary. In an uncomplicated case, most of these medications can be weaned over the 6 months following the Fontan operation. Some researchers advocate using aspirin indefinitely.
• Orthotopic cardiac transplantation
• • Heart transplantation is another surgical option. The infant must remain on prostaglandin E1 infusion to keep the ductus arteriosus patent while waiting for a donor heart to become available. Approximately 20% of infants listed for heart transplantation die while waiting for a suitable donor organ.
  • After successful cardiac transplantation, infants require multiple medications for modulation of the immune system and prevention of graft rejection. Perform frequent outpatient surveillance to identify rejection early and prevent lasting damage to the transplanted heart. Periodic endomyocardial biopsy usually is performed for more precise monitoring.

Consultations

• Consult a pediatric cardiologist.
• Consult a pediatric cardiovascular surgeon.
• Consult a genetic specialist if a chromosomal abnormality is suspected.

Diet

• Adequate nutrition is important before and after surgery. Many infants require nasogastric feeding with increased-calorie breast milk or formula after the Norwood procedure. However, normal oral feeding is reestablished with time. Adequate oral iron intake prevents development of iron deficiency anemia.
• After completion of the Fontan operation, specific dietary restrictions are not necessary.

Activity

• Specific activity restrictions are not imposed on children after completion of the Fontan operation. In general, encourage children to participate in activities that they are able to tolerate.
• Studies have shown that these children may have impaired exercise performance when compared to age-matched peers. Perform an exercise stress test when the child is old enough.
• Neurodevelopmental abnormalities occur often in patients with hypoplastic left heart syndrome.

MEDICATION

Section 7 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Before the Norwood procedure or cardiac transplantation, treat infants with prostaglandin E1 infusion, diuretics, inotropes, and afterload reduction. The medical management after cardiac transplantation is not discussed in this article.

Drug Category: Prostaglandins

Prostaglandin E1 promotes dilatation of the ductus arteriosus in infants with ductal-dependent cardiac abnormalities.

Drug Category: Diuretic agents

These agents decrease preload by increasing free-water excretion. Decreasing preload may improve systolic ventricular function.

Drug Category: Cardiac glycosides

These medications improve ventricular systolic function by increasing the calcium supply available for myocyte contraction.

Drug Category: Inotropic agents

These agents stimulate alpha-adrenergic and beta-adrenergic and beta-dopaminergic receptors in the heart and vascular bed.

Drug Category: Afterload-reducing agents

Afterload reduction improves myocardial performance and theoretically reduces atrioventricular and semilunar valve insufficiency.

Drug Category: Antiplatelet agents

These agents are used in the treatment or prevention of thrombo-occlusive disease mediated by the action of platelets. They inhibit platelet function by blocking cyclooxygenase and subsequent aggregation.

FOLLOW-UP

Section 8 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Further Inpatient Care

• Initial preoperative management and postoperative care take place in the neonatal, pediatric, or cardiac ICUs.
• When postoperative patients are clinically stable, transfer them to the general cardiac unit for adjusting oral medications, addressing feeding issues, and completing discharge teaching.
• Involve a pediatric cardiologist during any noncardiac hospital admission of a patient who is status post (S/P) Norwood procedure. This is because of the complex cardiovascular physiology in infants after this surgery.

Further Outpatient Care

• Schedule outpatient follow-up care 2 weeks after discharge in the typical postoperative patient.
• Schedule those who are S/P cardiac transplantation earlier for necessary laboratory studies.
• Earlier follow-up care is also necessary if a pericardial effusion is discovered on the discharge echocardiogram.
• Individualize further outpatient follow-up care based on the needs of each patient.

In/Out Patient Meds

• Inpatient medications
• • Prostaglandin E1
  • Dopamine/dobutamine
  • Furosemide (Lasix/Aldactone)
  • Captopril
  • Digoxin
• Outpatient medications
• • Furosemide (Lasix/Aldactone)
  • Captopril
  • Digoxin

Transfer

• Transfer the infant to a hospital with appropriate ICUs. Pediatric cardiology and cardiovascular surgery services must be immediately available.
• Carefully monitor the infant for apnea during transfer while on prostaglandin E1 therapy. If prostaglandin E1 has been started, consider elective endotracheal intubation before transfer.

Complications

• Preoperative complications include acidosis, CHF, renal failure, liver failure, necrotizing enterocolitis, sepsis, and death.
• Postoperative complications include acidosis, CHF, renal failure, liver failure, necrotizing enterocolitis, sepsis, pericardial or pleural effusion, phrenic or recurrent laryngeal nerve damage, stroke, coarctation of the aorta, and death. Early graft rejection and opportunist infection may occur after cardiac transplantation.
• Major complications following the Norwood procedure include aortic arch obstruction at the site of surgical anastomosis and progressive cyanosis caused by limited blood flow through the shunt. An inadequate atrial communication contributes to progressive cyanosis.
• Major complications following the hemi-Fontan procedure include transient superior vena cava syndrome and persistent pleural or pericardial effusion. The development of systemic venous to pulmonary venous collateral vessels is possible.
• Major complications following the Fontan procedure include persistent pleural or pericardial effusion. Neurodevelopmental abnormalities are reported and may be inherent in some patients with hypoplastic left heart syndrome.

Prognosis

• Overall survival to the time of hospital discharge after the Norwood procedure is nearly 75%. Success rates are higher in uncomplicated cases and lower in cases in which important preoperative risk factors are present, such as age greater than 1 month, significant preoperative tricuspid insufficiency, pulmonary venous hypertension, associated major chromosomal or noncardiac abnormalities, and prematurity.
• Survival after the hemi-Fontan and Fontan operations is nearly 90-95%.
• The actuarial survival rate after staged reconstruction is 70% at 5 years.
• Institutional success rates vary.
• Neurodevelopmental prognosis is not known; however, abnormalities are reported.
• Approximately 20% of infants listed for cardiac transplantation die while waiting for a donor heart. After successful transplantation, the survival rate at 5 years is approximately 80%.
• When the preoperative mortality is considered, the overall survival rate after cardiac transplantation is approximately 70%, or similar to the results for staged reconstruction.

Patient Education

• Medication
• • Educate parents regarding the doses and side effects of their child's cardiac medications.
  • Discuss interactions with other medications with the family and the infant's general pediatrician.
• Feeding
• • Many infants require nasogastric tube feeding after discharge from the hospital. Parents must become comfortable with placement of the nasogastric feeding tube.
  • Frequently, increased-calorie formula is required for adequate growth. Provide the formula recipe or a source for purchasing it to the caregiver.
• Follow-up care
• • Stress the importance of follow-up care. If necessary, provide cab or bus vouchers to ensure compliance.
  • If noncompliance becomes a critical issue, physicians are required to report to the appropriate family services agency.

MISCELLANEOUS

Section 9 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Medical/Legal Pitfalls

• Misdiagnosis
• Failure to recognize the infant with hypoplastic left heart syndrome and the obstruction to pulmonary venous return

Special Concerns

• The newborn with hypoplastic left heart syndrome dies rapidly if untreated. Surgical techniques, both reconstruction and heart transplantation, offer an opportunity to preserve the newborn's life. Survival rates given above represent the best results and reflect only survival, not quality of life. Mortality rates in many centers exceed those mentioned. Incidence of neurodevelopmental abnormalities in hypoplastic left heart syndrome appears to exceed that of other single-ventricle conditions.
• Hypoplastic left heart syndrome affects family structure. For example, reproductive studies indicate that the incidence of subsequent pregnancy is significantly lower in mothers of a living patient with hypoplastic left heart syndrome than in mothers after death of an infant with hypoplastic left heart syndrome. For these reasons, most pediatric cardiologists continue to offer no treatment as an acceptable option to parents of a newborn with hypoplastic left heart syndrome. It is incumbent on physicians caring for a newborn with hypoplastic left heart syndrome to clearly communicate all of this information to the parents. An ethically appropriate consent for surgery requires this. Allowing an affected infant to die without surgical intervention is a difficult decision, but it is still chosen by some families.

MULTIMEDIA

Section 10 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Media file 1:  This echocardiographic still frame shows a long-axis view of the aortic arch in a patient with hypoplastic left heart syndrome. The ascending aorta is markedly hypoplastic, serving only to deliver blood in a retrograde fashion to the coronary arteries. An echo-bright coarctation shelf is seen at the insertion of the ductus arteriosus.
	View Full Size Image
Media type:  Photo

Media file 2:  This echocardiographic still frame shows a 4-chamber view of the heart in a patient with hypoplastic left heart syndrome. A large right ventricle (RV) and hypoplastic left ventricle (star) are seen. RA, right atrium; LA, left atrium.
	View Full Size Image
Media type:  Photo

REFERENCES

Section 11 of 11

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

• Atz AM, Feinstein JA, Jonas RA, et al. Preoperative management of pulmonary venous hypertension in hypoplastic left heart syndrome with restrictive atrial septal defect. Am J Cardiol. Apr 15 1999;83(8):1224-8. [Medline].
• Backer CL, Bove EL, Zales VR. Hypoplastic left heart syndrome. In: Cardiac Surgery. New York, NY: Churchill Livingstone;1994:442-53.
• Bailey L, Concepcion W, Shattuck H, Huang L. Method of heart transplantation for treatment of hypoplastic left heart syndrome. J Thorac Cardiovasc Surg. Jul 1986;92(1):1-5. [Medline].
• Barber G. Hypoplastic left heart syndrome. In: Garson A Jr, Bricker JT, Fisher DJ, Neish SR, eds. The Science and Practice of Pediatric Cardiology. 2nd ed. Philadelphia, Pa: Lippincott Williams & Wilkins;1998:1625-45.
• Bove EL, Lloyd TR. Staged reconstruction for hypoplastic left heart syndrome. Contemporary results. Ann Surg. Sep 1996;224(3):387-94; discussion 394-5. [Medline].
• Bove EL. Current status of staged reconstruction for hypoplastic left heart syndrome. Pediatr Cardiol. Jul-Aug 1998;19(4):308-15. [Medline].
• Day RW, Barton AJ, Pysher TJ, Shaddy RE. Pulmonary vascular resistance of children treated with nitrogen during early infancy. Ann Thorac Surg. May 1998;65(5):1400-4. [Medline].
• Fontan F, Baudet E. Surgical repair of tricuspid atresia. Thorax. May 1971;26(3):240-8. [Medline].
• Freedom RM, Benson LN. Hypoplastic left heart syndrome. In: Moss and Adams Heart Disease in Infants, Children, and Adolescents. 5th ed. 1995:1133-1153.
• Norwood WI, Kirklin JK, Sanders SP. Hypoplastic left heart syndrome: experience with palliative surgery. Am J Cardiol. Jan 1980;45(1):87-91. [Medline].
• Norwood WI, Lang P, Hansen DD. Physiologic repair of aortic atresia-hypoplastic left heart syndrome. N Engl J Med. Jan 6 1983;308(1):23-6. [Medline].
• Pizarro C, Malec E, Maher KO, et al. Right ventricle to pulmonary artery conduit improves outcome after stage I Norwood for hypoplastic left heart syndrome. Circulation. Sep 9 2003;108(10 Suppl 1):II155-II160. [Medline].
• Talner CN. Report of the New England Regional Infant Cardiac Program, by Donald C. Fyler, MD, Pediatrics, 1980;65(suppl):375-461. Pediatrics. Jul 1998;102(1 Pt 2):258-9. [Medline].

Article Last Updated: Aug 15, 2006