Double inlet left ventricle is a rare birth defect, which results in one of the heart's ventricles (lower chambers where blood is pumped out) being less developed than it should be.
Double inlet left ventricle is one kind of single ventricle heart defect because there is only one pumping chamber in the heart that works. Single ventricle defects are some of the most complex heart birth defects.
With double inlet left ventricle, both the tricuspid valve and the mitral valve lead into the left ventricle. The tricuspid valve and mitral valve act as doors into the heart, letting blood flow into different chambers. Because the right ventricle is not being used, it is small and not well developed.
Surgery is needed to correct the condition.