 Thank you Dr. Chan and the ISU Organizing Committee for the opportunity to present here today. My name is Azad Mashari, I'm a Cardiac Anesthesiologist at Toronto General, and I'll be presenting to you today, Cardiac Anatomy for TE. Otherwise indicated on the slide, all the material in this presentation is licensed under Creative Commons license, and can be shared freely with attribution, and it's all available at the link presented there. These are my disclosures. Most of my work is funded by the UHN Foundation and our UHN HHS Anesthesi Association. I collaborate with a number of companies on research with no direct compensation. So I'm presenting anatomy for our cardiography today. I'm going to take a bit of a different approach than what you may have seen before. I'm going to focus on the heart base, which corresponds roughly to the fibrous skeleton of the heart, and it's basically the supporting structure for all of the valves in the heart and anchors all the major structures and chambers in the chest. We're going to go through a quick schematic that you can memorize very easily and draw at will that will help you orient all the valves and leaflet segments and name them. And we can then anchor all the rest of the cardiac structures to the heart base and visualize the position of everything in 3D quite easily. So you'll be able to visualize in the patient's chest where the heart base would be and where all your cardiac windows and key structures are. And at the end we'll focus on some of the key cut planes and focus to EVs. So on the left here we have the schematic of the heart base that we will end up with and on the right the 3D model of the same structure. These are both being viewed from the right shoulder towards the apex of the heart or from the side of the atria and the great vessels towards the sides of the ventricles. I would highly recommend you draw along with me. So the first step is to draw three circles and mark the centers. In the center we have the aortic valve, in front of it the pulmonary valve and the large circle on the side represents the tricuspid valve and then we make a jelly bean for the mitral valve. We have a little orientation marker there for anterior left and right in quotations because these are in relationship to the traditional orientation terms for the heart which do not match the standard anatomic terminology. So the next step is to connect the centers of the circles with two lines and finally we divide each circle into equal thirds. So this gives you the correct location of all the commissures and leaflet separations. Another nomenclature that might be helpful is to put a big red nose on the aortic valve. So again the steps where we draw three circles, we mark the centers, we connect the centers and then divide them into equal thirds. And once we have that, it's quite easy to label the leaflets of all the valves. So the aortic valve in the center has a right coronary, a left coronary and a non-coronary cusp. The pulmonary valve has a right, left and anterior leaflets, tricuspid valve has anterior, posterior and septal leaflets, and the mitral valve has anterior and posterior leaflets. So now with this diagram in mind, we're again looking from the atrial side towards the ventricles, picture where the atrial septum would be, where the right atrial and left atrial appendages would be, and where the coronary sinus would be. So here we have added those, so you can see the atrial septum separates the right atrium that would be over the tricuspid valve from the left atrium that would be over the mitral valve. The coronary sinus travels behind the mitral valve annulus into the right atrium and near the junction of the septal and posterior leaflets and the atrial appendages are illustrated there as well. So I'm going to try to picture what the LV and the RV would look like from this vantage point. So the LV would have to include the inflow and the outflow of the left and the RV would include the inflow and the outflow of the right. So that's what they would look like. So the LV, looking down its long axis towards the apex, looks oval or circular and the RV looks like a boomerang or a banana because of the separation between the inflow and the outflow. So this groove here, obviously very exaggerated, corresponds to the anterior interventricular groove and this would be the posterior interventricular groove. So your LAD would travel along here. I'm now adding a few more details and making the tricuspid annulus shape a bit more realistic. We have this diagram. We've marked the sub-segments of the mitral leaflet if you're interested in that level of detail. I've added the circumflex coronary artery that comes off the left main, which comes off the left coronary cusp and again the LAD runs in here down the groove that we mentioned. We have the coronary sinus here coming at the commensure between the septal and the posterior leaflets of the tricuspid valve and these dotted lines here represent the four chamber and the long axis cut planes that we'll discuss in a bit more detail. On the left here, we have the 3D CT-based model of the heart base, which we'll go through again. At this link here, there's an interactive 3D model that you can play with on your device. So now we're going to leap off the flat page into three-dimensional space. We're going to be using this cardiac gated CT-based model. What's shown here are the blood volumes of the heart chambers, so the muscle and the vessel walls have been removed so that you can actually see the internal cavities and the connections between the chambers most clearly. For orientation, we have this CT slice at the bottom that helps you orient. You can see the spine at the back. We also have this yellow man on the side here. In addition, this patient had a previous sternotomy for cardiac surgery, so he has sternal wires that will display in some of the views so that it can help us see where the sternum would be without obstructing our view. And if you look closely, you can actually see the Hisaphanous vein grafts attached to his ascending aorta. So the main thing to notice going from the fat schematic diagram of the heart base to a three-dimensional morphology is that the aortic valve and the pulmonary valve are not coplanar. So the long axis of the pulmonary valve sets along the mid-sagittal plane going from roughly your zephysternum to your lower c-spine, while the long axis of the aortic valve goes from the right humeral head to the apex. So it looks like a couple of chopsticks. We have the anterior view and the left lateral view there. And here we have the posterior view that's kind of our vantage point with TEE. And you can see the esophagus where the TEE probe would be traveling along. So here behind the mitral valve annulus would be left atrium. So that's our midisophageal window there. And that's what the heart base looks like from the midisophageal window. So again, we can see the long axis of the aortic valve and the pulmonary valve. And now to locate the heart base, you can see that the aortic valve is directly behind the sternum and that the planes of the mitral and tricuspid valves are essentially vertical. So with those in mind, you should be able to visualize the heart base inside a patient's chest in front of you or visualize your own heart base. So now we start adding the other structure. So here we have the left heart. We've got the left ventricle passing through the view now. The left atrium is coming into view. And you can see how it's anchored to the mitral valve ring there. We have the left atrium from the back. And here you can see the aorta coming out of the aortic valve. And you can see the staphonous vein grafts in the ascending aorta. And you can see the RCA there, the left main. Here you can see the septal surface of the left ventricle. This is the anterior endocardial surface. That cavity corresponds to where the entrolateral papillary muscle would be. We're looking at the aorta. And you have the ascending aorta, the aortic arch and its branches and the descending aorta. Again, you can see the coronary arteries, just the proximal portions of them. Just as the aorta leaves the heart base. So that's the RCA. And that's the left main. So next, we're looking at the right heart blood pool now. So you can see the right ventricle going from the tricuspid valve to the pulmonary valve as triangular shape. You can see the coronary sinus wrapping around the mitral valve annulus just coming into view now. And the posterior descending vein. The coronary sinus drains into the right atrium. And you can see a little bit of the IVC and the SVC coming into the right atrium, the right atrial appendage and the triangular shape of the RV, the RV outflow tract and the main PA, the left PA and the right PA passing behind the SVC. And here, we put everything together. I may be a bit overwhelming at first, but if you look at it piece by piece and remember how it was assembled with the left blood pool in the orange and red and the red blood pool in the light and dark blue and the heart base in the center anchoring everything together. So you can see the relationship between, for example, the pulmonary artery and the left atrium between the pulmonary artery and the pulmonary veins. And as the model turns around, note also the location of the esophagus and the airway. So next, we're looking to look at cut planes, windows and views. And the extinction here is pretty important. So cut planes are tomographic slices through the image and these can be defined typically by three landmark points. So for example, for the long axis view cut plane that is shown here it can be defined by the center of the aortic valve, the center of the mitral valve and the LVA pecs. And for a given cut plane, we have different windows that allow us to see parts of it and we have different views from those windows. So for example, for the long axis cut plane, we can view it from the parasternal window, the apical window or the midisophageal window. And you can see on the right with the on fast image of the slice. As you remember, we have some limitations with TE in terms of what we can see, mainly because of the interposition of the airway between the esophagus where the probe sits and the cardiac structures. So we have two broad blind spots. One is between the midisophageal and upper esophageal windows and that's caused by the carina and the main stem bronchi. And the other one is at the top caused by the upper trachea and it obstructs our view of the distal ascending aorta and the proximal aortic arch. So these are the typical definitions for the windows for TE. So above the left main stem bronchus we have the upper esophageal window. Behind the left atrium we have the midisophageal window, below that the lower esophageal window and then the transgastric window. Now to visualize the views in 3D space, you have to remember the left hand rule. So if you pretend that the echo probe is in your wrist and the omni plane is represented by your left hand, rotation of your left hand goes from 0 to 180 as represented by that compass rose. And again this is the view from the esophagus looking towards the heart base. So the view that the echo probe would have. And to cause further confusion, we typically look at these images rotated so that the left heart is seen on the right and the right heart is seen on the left. So we're going to look at the three major cut planes. The first one is the four chamber cut plane. The landmarks for which are the centre of the mitral valve, the centre of the tricuspid valve and the apex. And we have various windows. So in TE we only have the midisophageal window but in transgastric echo we also have the apical and subcostal windows that can allow us to see parts of this cut plane. So again here we have the same CT representation of the cut plane with all the cardiac structures showing. And on the left, an on fast view corresponding to your mitisophageal four chamber. So along the top here you have the CT representation with the heart base of the four chamber view. Four chamber cut plane. And on the right you have an example of the four chamber TE view. And on the left the corresponding CT slice. The next major cut plane is the long axis cut plane. And the landmarks for which we discussed are the centre of the aortic valve, centre of the mitral valve and the apex. We can view this from the mitisophagus where we have the mitisophageal long axis view and the mitisophageal aortic valve long axis view which is essentially a zoomed in version of the same. And now we're showing all the structures again. And on the left an on fast view that corresponds to our mitisophageal long axis view. And again note the orientation little man there that we're looking from below the slice in TE. So here along the top again you have the cut plane shown in the four cardinal orientations. The cut plane on the left with the heart base embedded in it. So you can see that the tricuspid valve is in front of the screen. The RVOT is here. The pulmonic valve is behind the screen and the aortic valve is going through the slice. And the last major cut plane is the mid papillary short axis plane. So this plane is defined as being perpendicular to the long axis of the RV. So if you imagine the line running from the centre of the mitral valve to the apex and it's located midway between the mitral valve plane and the apex at the level of the papillary muscles. This view is significant because in most patients you have all three major coronary territories represented here. And in addition this cross section is least susceptible to distortions because of the heart moving in and out of your imaging plane. So in south of Geolecho our main window onto this view is the trans-gastric mid papillary short axis. So here we have the same view now with all the cardic structures and on fast view corresponding to your trans-gastric short axis view. And here again the slice represented at the top the on fast view at the bottom and the echo clip. So we learned how to draw the heart base how to visualize its morphology and position in the chest so that we can look at a patient or ourselves and picture the heart base in the heart. We can build all the major cardiac chambers around the heart base and visualize the principal cut planes and our cartographic views around that. Thank you very much for your time. I'd like to thank my lab collaborators and my mentors. A full copy of this presentation and all the materials are available at the link. Thank you very much.