Hypoplastic Left Heart Syndrome (HLHS)
Hypoplastic left heart syndrome (HLHS) is a rare and complex congenital heart defect that affects the left side of the heart. It is characterized by the underdevelopment of the left ventricle, mitral valve, aortic valve, and aorta.
Causes and Risk Factors
The exact cause of HLHS is not known, but it is believed to be related to genetic factors, environmental factors, or a combination of both. Some risk factors that may increase the likelihood of having a child with HLHS include:
- Family history of congenital heart defects
- Maternal diabetes
- Maternal obesity
- Advanced maternal age
Symptoms
Babies with HLHS may exhibit the following symptoms:
- Cyanosis (blue discoloration of the skin)
- Shortness of breath
- Rapid breathing
- Fatigue
- Poor feeding
- Sweating
- Irregular heartbeat
Diagnosis
HLHS is typically diagnosed during fetal development or shortly after birth. Diagnostic tests may include:
- Fetal echocardiogram (ultrasound of the heart)
- Chest X-ray
- Electrocardiogram (ECG)
- Echocardiogram (ultrasound of the heart after birth)
- Cardiac catheterization
Treatment
Treatment for HLHS usually involves a series of surgical procedures, including:
- Norwood procedure: The first surgery, typically performed within the first week of life, which involves creating a new aorta and connecting it to the pulmonary artery.
- Glenn procedure: The second surgery, typically performed at 4-6 months of age, which involves connecting the superior vena cava to the pulmonary artery.
- Fontan procedure: The third surgery, typically performed at 2-3 years of age, which involves connecting the inferior vena cava to the pulmonary artery.
In some cases, a heart transplant may be necessary. Medications and other interventions may also be used to manage symptoms and support the child's overall health.
Prognosis
The prognosis for children with HLHS has improved significantly in recent years due to advances in medical and surgical care. However, the condition is still associated with significant morbidity and mortality. With proper treatment and management, many children with HLHS can lead active and fulfilling lives.
Complications
Possible complications of HLHS include:
- Respiratory problems
- Cardiac arrhythmias
- Heart failure
- Protein-losing enteropathy (a condition in which the body loses protein)
- Plastic bronchitis (a condition in which the airways become inflamed and obstructed)
Regular follow-up care with a cardiologist and other healthcare providers is essential to monitor for potential complications and adjust treatment as needed.
Frequently Asked Questions (FAQs)
What is Hypoplastic Left Heart Syndrome (HLHS)?
A rare congenital heart defect where the left side of the heart is underdeveloped.
What are the typical symptoms of HLHS?
Symptoms may include pale or blue-tinged skin, rapid breathing, and poor feeding.
Is HLHS usually diagnosed at birth?
Often diagnosed prenatally or shortly after birth, but sometimes diagnosis may be delayed.
What are the treatment options for HLHS?
Treatment typically involves a series of surgeries, including the Norwood procedure, Glenn procedure, and Fontan procedure.
Can medication alone manage HLHS?
Medication may be used to stabilize the condition initially, but surgery is usually necessary.
Is heart transplantation an option for HLHS patients?
In some cases, heart transplantation may be considered, especially if other treatments are not viable.
What is the prognosis for children with HLHS?
Prognosis varies depending on individual circumstances, but many children can lead active lives with proper treatment.
Are there any genetic factors associated with HLHS?
While some cases may have a genetic component, the exact causes of HLHS are often unclear.
Can adults with HLHS-treated as children have normal life expectancy?
Some individuals may have near-normal life expectancy, but ongoing medical care is typically required.
Are there any specific activities or sports that should be avoided by HLHS patients?
Certain high-intensity activities or contact sports may be discouraged to minimize risks, depending on individual health status.
Article last updated on: 18th October 2025.
If you have any feedback, please get in touch.
See more
Medical AI Assistant with Differentials, Guidance, Transcriptions, Notes, Medical Encyclopedia and Explainable AI.
Medical Disclaimer
The information provided is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay seeking it because of something you have read on this site. We we do not guarantee, and assume no legal liability or responsibility for the accuracy, currency, or completeness of the information provided.