Hypoplastic Left Heart Syndrome
Hypoplastic Left Heart Syndrome (HLHS) is a severe congenital heart defect (present at birth) in which the left side of the heart is underdeveloped. In a normal heart, the heart's left side has the job of pumping oxygenated blood into the aorta (large artery that carries blood to the body). In a child with HLHS, there are several problems: the mitral valve is too small or completely closed; the left ventricle is very small; and the aortic valve is too small or completely closed. This results in a situation where the left side of the heart is completely unable to support the circulation needed by the body's organs.
Therefore, the right ventricle must do a "double duty" of pumping blood both to the lungs and out to the body (via a patent ductus arteriosus). The patent ductus arteriosus, a normal structure in the fetus, is often the only pathway through which blood can reach the body from the heart. When the ductus arteriosus begins to close, as it typically does in the first days of life, the blood flow to the body will severely diminish, resulting in dangerously low blood flow to vital organs and leading to shock. Without treatment, hypoplastic left heart syndrome is fatal, often within the first hours or days of life.
Causes of Hypoplastic Left Heart Syndrome
Doctors know that heart defects present at birth (congenital) arise from errors early in the heart's development, but there's often no clear cause.
Symptoms of Hypoplastic Left Heart Syndrome
Many people born with this condition have no signs or symptoms. However, as the condition worsens symptoms may start to appear. Some of these symptoms include:
- A bluish discoloration of the lips and skin caused by low oxygen (cyanosis).
- Poor feeding
- Difficulty breathing
- Easy tiring
Diagnosis of Hypoplastic Left Heart Syndrome
To diagnose this condition, your doctor will perform a variety of tests, including but not limited to:
- Echocardiogram (ECHO)
- Electrocardiogram (EKG/ECG)
- X-Rays
- Cardiac catheterization
- Computed tomography (CT scan)
- Magnetic resonance imaging (MRI)
Treatment of Hypoplastic Left Heart Syndrome
Hypoplastic left heart syndrome is most often fatal without early intervention. Therefore, intervention is critical. Some of the treatment options include:
- Surgical repair is done in stages up to the Fontan procedure. Those will survive and live into teenage or adult life often require additional cardiac surgical or transcatheter interventions.
- Many will also require pacemaker treatment or defibrillator implantation.
- Some may eventually require heart transplantation.