About Single Ventricle Heart Defects
In most cases, the cause of a single ventricle is unknown. There has not been any genetic link identified. The right or left ventricle's underdevelopment may allow oxygen-poor (blue) blood and oxygen-rich (red) blood to mix. Two or three surgeries treat single ventricle defects. Diagnosis will determine the first surgery but the second and third surgeries are usually the same no matter what kind of heart defect a child has.
What is a single ventricle heart defect?
A single ventricle heart defect is a congenital condition that occurs when one of the two lower chambers of the heart, known as ventricles, is underdeveloped, smaller, or missing a valve. The heart consists of four chambers: two upper chambers called atria and two lower chambers called ventricles. In a healthy heart, the atria receive blood and the ventricles pump blood out of the heart and back into the bloodstream.
In the case of a single ventricle heart defect, the abnormal ventricle doesn’t have the opportunity to practice pumping blood like the other chambers, so it is not able to fully develop. This results in the heart not being able to properly deliver oxygen to the bloodstream. There are several different classifications of single ventricle defects, but they all originate in the womb.
Single ventricle heart defects include conditions such as Hypoplastic Left Heart Syndrome (HLHS), where the left side of the heart is underdeveloped. Other types include Pulmonary Atresia/Intact Ventricular Septum, where the pulmonary valve does not exist, and Tricuspid Atresia, where there is no tricuspid valve in the heart.
A single ventricle defect poses a major problem for babies born with it, as their hearts aren’t able to circulate enough oxygen in their bloodstream to sustain their life. A baby or young child might appear blue, have a higher risk for heart infections like endocarditis, or experience blood clots and abnormal heart rhythms as a result of their one good ventricle working too hard.
The goal of the surgeries is to rebuild the heart and make sure that it:
Pumps blood out to the body
Returns the blood to the lungs (without being pumped by the heart as it would be in a child with two normal ventricles)
Returns the blood to the heart
A newborn with a single ventricle defect can have:
Trouble breathing
Trouble feeding
Blue or grayish color of the skin and nails
Lethargy (very little activity)
Weak pulses in the arms and legs
Few wet diapers