06/04/2026
Hypoplastic Left Heart Syndrome (HLHS) is one of the most severe and complex congenital heart defects, affecting the entire left side of the heart.
In a healthy heart, the left side pumps oxygen-rich blood out to the body. But in babies born with HLHS, the structures on the left side of the heart are critically underdeveloped. The left ventricle is too small to function properly, and the mitral valve, aortic valve, and aorta may be extremely small or not formed at all.
Before birth, babies survive because of two natural openings in the heart called the PDA and PFO that allow blood to circulate differently in the womb. After birth, those openings normally begin to close.
But for babies with HLHS, the PDA is often the only pathway allowing blood to reach the body.
When it begins to close, blood flow to vital organs rapidly decreases. Without treatment, HLHS is fatal.
Most children with HLHS undergo a series of three open-heart surgeries:
đź«€ Norwood
đź«€ Glenn
đź«€ Fontan
These surgeries are not a cure. They are palliative surgeries designed to reroute blood flow and help the heart function as effectively as possible.
And even after surgery, HLHS is lifelong.
Children and adults living with HLHS often face ongoing complications including arrhythmias, low oxygen levels, heart failure, liver and kidney complications, protein losing enteropathy, and some may eventually require a heart transplant.
HLHS is not “fixed” after surgery.
It requires lifelong specialized cardiac care, constant monitoring, and incredible strength from the patients and families living this reality every single day.
Today we honor the heart warriors born with HLHS, the families walking this journey, and the babies whose stories continue to live on in the hearts of those who love them.
If HLHS has impacted your life, we would love for you to share your story below. ❤️