In HLHS, addition to the small left ventricle, there is usually a hole in the wall between the two sides of the heart (either an atrial septal defect or patent foramen ovale).
HLHS occurs at a rate of up to 4 out of every 10,000 live births. It accounts for about 8% of all congenital heart defects. It occurs more often in infants with Turner, Noonan, Smith-Lemli-Opitz, or Holt-Oram syndromes.
Symptoms
While a fetus is in the womb, it receives oxygen from its mother's circulation through the placenta. So the infant with hypoplastic left heart syndrome develops normally during pregnancy and is usually born at full term. Once the infant is born, however, the placenta is removed and the infant has to rely on its own heart and circulation for oxygen. Signs of HLHS begin to show within the first 24 to 48 hours of life. The heart is unable to pump an adequate amount of oxygenated blood to the body. Symptoms may include:- Rapid heart rate
- Fast breathing
- Blue color of lips and face (cyanosis) and pale skin
- Cool, clammy skin
- Weak pulses in the arms and legs (due to poor circulation)
Diagnosis
If hypoplastic left heart syndrome is suspected in a fetus, an ultrasound of the heart (echocardiogram) will be performed. This will show the small left ventricle and any other defects present. If HLHS is not diagnosed prior to birth, when the infant is born, symptoms become apparent which suggest the diagnosis.Treatment
The infant born with HLHS will receive an intravenous infusion of a medicine called prostaglandin to help improve blood flow to the body. Open heart surgery will be needed to alter the heart to compensate for the small left ventricle. A series of surgeries reroutes the blood in the heart so that the right ventricle does the work of both ventricles (pumps blood to the lungs and out to the body). A heart transplant can also be done to give the infant a properly functioning heart.Fetal surgery
Researchers know that heart development of the fetus in the womb depends on adequate blood flow through the heart. In HLHS, little blood flows to the fetus' left ventricle, so normal growth of the left ventricle does not occur. Pediatric heart specialists (cardiologists) are trying to change this by inserting a narrow tube (catheter) into the fetus' heart while it is still in the womb and opening up the path for blood flowing to the left side. Increasing blood to the left ventricle will cause it to develop more normally and reduce the complications of HLHS.Source:
"Hypoplastic Left Heart Syndrome." My Child Has... Children's Hospital Boston. 24 Oct 2008.
