 Hey everybody, Dr. O. In this video I actually want to talk about coronary circulation but I more want to talk about what happens when it gets disrupted and we'll look at what are called myocardial infarctions or heart attacks. So here you see the coronary blood supply, don't make a big deal out of memorizing the individual blood vessel names here. You can see that your two coronary arteries there, they're the first branch off the aorta. So as the heart pumps blood, the first thing it does is it takes some for itself. And the coronary arteries are going to then, they're going to bathe the entire heart with oxygen rich blood so that the heart muscle cells continue to work, right? That it takes tons of energy to contract 3.2 billion times in your lifetime. And then once the blood has been used, it's going to be the cardiac veins that are going to carry the blood back and that blood will drain into the coronary sinus and then it's going to drain back into the right atrium so that you see the heart has its own circulatory system. But what I really want to talk about is what happens when this system breaks down. So here we see a couple of blockages in some of the arteries of the heart. That can lead to a myocardial infarction, which people call heart attacks. So a heart attack is going to be when you have a lack of blood flow, which is called ischemia or a lack of oxygen, hypoxia, usually both, right? Because the blood is carrying oxygen. And then if you don't get this dealt with quick enough, this lack of oxygen is going to lead to tissue death. The sections of the heart will die because of this lack of blood flow. So the two main causes of a myocardial infarction would be just a narrowed and then blocked artery because of a buildup of a atherosclerotic plaque. Plaque is going to be like, it's going to have lipids in it, cholesterol in it, like macrophages, some other white blood cells in it, these types of things. So you can have a narrowing of the artery that can slowly become blocked or, and I think this happens more often, it can be when a piece of plaque, actually let me go ahead and show you one. So here we have a plaque that's forming in an artery. Now that can slowly narrow and narrow to the point where it can become completely blocked. That can absolutely happen. But I think what happens more often is unstable plaques are going to break free and then they will lodge in an artery in your heart causing a myocardial infarction or heart attack, or they can lodge in the brain and cause a stroke. We're not talking about that here, but this is what a plaque looked like. So, so all of us have plaque forming in our blood vessels, but the stability of the plaque is what matters. And that's a topic that we cover in other classes like nutrition. But so those are the plaques. So this slow narrowing can lead to a myocardial infarction or an abrupt incident can occur when one of these plaques breaks free. So what do we do? Let's go back and look at some of these blockages so they can go in and do angioplasty. They snake up through one of your blood vessels and use a balloon to kind of smash the plaque up against the blood vessel walls. And then they usually put a stent in there, some of the stents even going to have drugs in them. It's pretty cool. You know, if you, if you are having a myocardial infarction, it's very important, but it doesn't seem to help anybody actually live any longer, you know, lowering your cholesterol and dietary changes. These are the kind of things that hopefully will, will extend life. If an angioplasty isn't the right way to go, they can do a coronary bypass where they will actually, they'll replace, they'll take a replacement vessel and graft it in to try to form a new highway around these blockages. So almost, almost a detour, so that's something that can happen as well. All right. So I just wanted to talk about, I don't really, I don't care about the individual names of the coronary arteries, but I just wanted to talk about why they're important because if they stop working, that leads to a myocardial infarction, myocardial infarction. Last thing here, you know, myocardial infarction can trigger a cardiac arrest where the heart stops beating, but it doesn't actually have to. It does a lot though. Okay. Is that just some interesting facts there about, about myocardial infarction? Actually, let's talk about one more thing. Let's talk about some of the symptoms some of them would be having if they were, if they were having a heart attack. So the reason I want to talk about this is because there's lots of symptoms and there's a couple reasons that this is important. Number one, symptoms are not always the same in men and women. So when you think of, when you think about heart attack, usually think about pressure in the chest, maybe pain behind the sternum, some of this pain radiating down the left arm, but that doesn't really happen as much in women. So prior to our understanding that there were differences between men and women when it came to heart attack symptoms, a lot of women were sent home with indigestion or something and that was a terrible idea. Another reason it's important to understand the symptoms of heart attack is because they're very similar to anxiety attacks, some indigestion, right? There are lots of other things that can be misconstrued for heart attack and vice-versa. So that's why it's so important that you use other tests and do what's called the differential diagnosis to figure out, is this indigestion? Is this an anxiety attack or something? Or is this a heart attack? And then we won't go to all the details there. That's, I'll save that for your more clinical courses. And then the sad reality is a pretty large percentage of myocardial infarctions don't have any symptoms, so you don't actually know what's going on and sadly the first symptom could be death. All right, so you can look at the rest of these here, some of these are going to sound pretty familiar to you, but remember that one key difference that females often don't have that pain radiating down the left arm that we consider very typical of heart attacks. Okay, I hope this helps. Have a wonderful day. Be blessed.