Heart interview?

why is a typical 4 chamber heart more efficient than a 3 chamber heart?Heart interview?
In a 3 chamber heart the oxygenated and deoxygenated blood is mixed surrounded by the ventricle, therefore the blood received by the body is smaller number oxygenated that the blood received by the body of a organism with a 4 chamber heart. This will lower metabolism and other body functions.
I don't know adequate about the mechanics of a 3 chamber heart...
I hold whats called 'single ventricle' (two atria, one ventricle.) I'm 22, I'm a paramedic. I've have 3 open heart surgeries to correct some issues, but since after (last one was when I be 4) I have have ZERO problems.
It's more efficient as a 4 chamber by design, Harmony be right about the blood mixing.
But, I don't want you to imagine it means you can't be mundane. You can. :)