OK, so here is a more detailed description of Lynnea's condition. The first picture is a picture of Lynnea's heart. I apologize for not having a "normal" heart picture up here for a reference, but I couldn't find a good pic of a prenatal heart, which is the closest thing to what her heart is like. There are lots of things that are anatomically wrong with Lynnea's heart. First, her left ventricle (LV on illustration) is very small, and not very useful. Second, she has a condition called Mitral Atresia, which means that her Mitral valve didn't form properly, so instead of having a valve, she has a solid wall (this is marked in orange on the drawing). This means that it is impossible for blood to flow from her left atrium (LA on illustration) down to her left ventricle (the top chamber and the bottom chamber of the left side of her heart).
Next, her Aorta (blue in the illustration), which normally serves to send oxygenated blood to the entire body, is very narrow, so very little blood is able to be pumped through it.
Finally, Lynnea also has an "extra" hole between her right ventricle and her left ventricle (marked as the yellow area on the illustration).
In addition to these deformities, Lynnea still has, and even more importantly, still uses some of her prenatal heart "parts" for lack of a better word. Normally, before babies are born, they have a hole between their right atrium and their left atrium, called a PFO (marked in red on the illustration). They also have an extra duct called a PDA (marked in green on the illustration) that connects the Pulmonary artery (purple on the illustration) to the Aorta (blue on the illustration). These things exist because, before babies are born, their blood doesn't need to flow to their lungs for oxygenation because babies don't actually breathe before they are born. Sometime after birth, these parts close up because babies don't need them anymore. Unfortunately, in Lynnea's case, these things made it possible for her to compensate for all of the defects that her heart has.
Before the surgery that Lynnea had on Thursday, the doctors were giving her a drug to keep her PDA open. The second illustration shows what Lynnea had done during her surgery. First, she had a stent placed in her PDA (green on illustration) to permanently keep it open. Second, she had bands placed around parts of her pulmonary artery to help regulate the blood flow through there because too much blood was flowing to her lungs at one time (Purple on illustration). Finally, they pushed a tiny balloon through her PFO to help temporarily keep it open (red on illustration). Ideally, this will keep the PFO open until her second surgery when they hope to make it a permanent opening. If it begins to close before her second surgery, they will have to go in again with a balloon to keep it open longer. This means we will most likely have to make weekly visits here at the hospital so that they can check it to make sure it's not closing.
The last we heard from the surgeons is that she will probably have the second surgery in five or six months. It will be a much more intrusive procedure, and it will be necessary for her to be on a heart/lung machine for it (this first procedure was open heart, but did not include complete pulmonary and cardiac arrest). It will include some reconstruction of her aorta, as well as re-routing the blood flow from the upper half of her body, sending the unoxygenated blood directly to the lungs for oxygenation, rather than sending it to the heart. In the long run (after the final surgery is completed when she is two or three years old) all of her unoxygenated blood will travel to her lungs, so that her heart is only responsible for pumping oxygenated blood to the rest of her body. In a way, this first surgery only provided some temporary solutions to help Lynnea make it to her second surgery. And, even after all three procedures are completed, the doctors pointed out that the right side of any heart is technically not designed to do all of the pumping of oxygenated blood to the body, and over time will wear out, making a heart transplant necessary for Lynnea sometime in the future.