 Let's talk about Ebbsteins. Ebbsteins are not only the tricuspid valve. Ebbsteins, as you know, is an exaggeration of the normal. Here's the normal, the tricuspid valve is more apical than the mitral, and in Ebbsteins, this is displaced even further. So here's normal, and here's Ebbsteins. It's displaced even further down here. And always with Ebbsteins, not only is this displaced, but there's tricuspid regurgitation, and the principal path of physiology is that of significant tricuspid regurgitation. Patients with Ebbsteins can do very well and have no surgery and have normal qualities and life longevity, depending upon how much tricuspid regurgitation there is, even if there's Ebbsteins anomaly. On the other hand, patients with a lot of tricuspid regurgit can have very dilated hearts that are at risk for heart failure, prenatally, they're at risk for arrhythmias, that could be fatal arrhythmias. And so these very high risk subset of fetuses in utero, many cases will, there'll be fetal demise. And sometimes we've been very aggressive trying to get these babies to term. A lot of times they will just spontaneously show up having demise, late ingestation, very high risk subset of patients. This is the tricuspid regurgitation I was mentioning to you. This is the wall-to-wall heart, very big right atrium, that's very typical of Ebbsteins. Ebbsteins and tricuspid valve dysplasia have similar pathophysiology. Tricuspid valve dysplasia you just don't have apical displacement, but the physiology and the approach is very similar. And here you could see dilate, again dilated right atrium, you could see the flap of the frame in extends well into the left atrium because of all the TR and all the flow going across the atrial septum and here you could see a very abnormal tricuspid valve. Some of these cases, the tricuspid valve is so abnormal that it's not, we cannot fix it and we have to turn these patients, we over-sow the right ventricle and turn it into a single ventricle. Other patients do great and have very good prognosis. Another thing that's very important in terms of evaluating before birth is whether there's prograde flow across the pulmonary valve. Oftentimes the pulmonary valve may look like it's normal, but it doesn't open because there's so much tricuspid regurgitation. And here you could see in this fetus, there's what we call functional pulmonary valve atresia. It's really a normal pulmonary valve, I know that because we saw the baby after birth and it worked. But there's retrograde flow in the ductus into the PA because there's no opening of the pulmonary valve. This is not a good prognostic feature to see prenatal, and it does mean that this baby may be sicker than the fetus with abscene who has prograde flow across the pulmonary valve. Sometimes these babies after birth require early surgery. Sometimes as the pulmonary vascular resistance falls and the ductus closes without surgery they can get better. So it's very complicated and it's important when you're counseling these patients with abscenes to be sure that you understand what happens to these children after birth. This is a newborn with abscenes. This is the atrial septum with right to left shunting because of the tricuspid regurg. There's right to left shunting. These babies are often cyanotic after birth. And this is the same fetus I showed you with functional pulmonary valve atresia before birth. After birth without surgery this is the pulmonary valve and this is prograde across the pulmonary valve and flow into the right pulmonary and to the left pulmonary. So the prognosis of abscenes is very variable. Some do very well, some do very poorly. And so it's important to understand that when you make a diagnosis to be able to counsel appropriately. Also some of these babies I didn't mention but many of these babies have WPW accessory electrical connection putting them at risk for SVT. So let's talk about tricuspid atresia. Tricuspid atresia is if you're going to be born with a single ventricle tricuspid atresia is the one you would want why is that? It's because if you have tricuspid atresia the right ventricle is underdeveloped but the left ventricle is usually very well formed and you'd rather have a single left ventricle than a single right ventricle. They tend to develop heart failure less frequently than single right ventricles but it's still a single ventricle with a guarded prognosis even with tricuspid atresia. Here's a case of tricuspid atresia. You could see the tricuspid valve is plate light over here. You could see the ventricular septal defect here in the hypoplastic RV. And here's the mitral valve. Here's the flow across the mitral valve. No flow across the tricuspid but flow through the ventricular septal defect. This can be diagnosed even early on first trimester screening. Sometimes the outflow tracks are hard but you could put color on even for the four chamber here. If you just look by 2D it's hard to tell exactly what's going on. You put color on and you see there's no flow across the tricuspid valve. Single in flow.