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Current time:0:00Total duration:7:53

Stenosis, ischemia and heart failure

Video transcript

is someone who's married to a doctor in the medical field I think it's pretty important to have a precise understanding of what the words mean just so that you can understand what people are talking about if either you are a healthcare professional or if some healthcare professional is talking to you as my wife does when well sometimes does when she comes home from work so let's get a little bit more precise with some of the words we've been talking about especially relative to heart disease and heart failure and all of the rest so let's say this is an artery the blood is flowing in that direction I'll show the artery branching off thins it goes further and further along so this right here is an artery and let me draw a plaque in that artery and we've been we've been studying these plaques in arteries since the video on on heart attacks so let's say this is a bunch of white white blood cells and and lipid material so it's cholesterol and fats and all the rest now a word that you might hear in kind of a medical context is stenosis stenosis stenosis and the word stenosis just refers to the narrowing usually of a blood vessel so this right here this blood vessel has been narrowed so this right over here is stenosis it's been narrowed by this plaque it can also refer to the narrowing of kind of any type of tubular structure so if you have any type of kind of pipe in a in a biological system and it gets narrowed they might refer to stenosis there but usually they're talking about a blood vessel and this in this example that I've drawn here it's an artery so thus enosis is just the narrowing is just the narrowing now once once the blood vessel is narrowed that restricts the blood supply so you aren't able to get as much blood through it you're not able to get as much blood through it so the blood supply is restricted so a restricted blood supply restricted the eye they're restricted blood supply this restriction of a blood supply that usually loses that usually leads to some type of loss of function that's called so this restricted blood supply this is called ischemia another fancy word but little it just means restricted blood supply is Kimia now if you have stenosis in one of your blood vessels in one of your arteries and it restricts your blood supply so it leads to ischemia then the muscles let's say let me draw a muscle cell further over here let's say that these are this is a coronary artery that we're dealing with the muscle cells over here are going to get less oxygen so this guy let me draw this cell right over here and I'm just drawing an oversimplified diagram I'm not going to imply that muscle cells really look like that and actually they won't be well I won't go to the details here but this guy's not going to get not not enough not enough oxygen not enough oxygen so you can imagine that if you know we're really zoomed in onto the surface of the heart we're looking at the heart muscle tissue right here if whoever his heart this was if they started to go jogging or whatever and this and this cell needed more oxygen probably wouldn't be able to get that oxygen because of the stenosis which caused ischemia and because of that it doesn't have enough oxygen so that the heart it won't be able to help the heart pump remember this is just one of the muscles in the heart that's going to help it pump the blood properly so it's going to lead to heart failure heart failure and once again the word heart failure sounds more dramatic than maybe it really is it sounds like cardiac arrest where the heart stops but heart failure is not saying that the heart has completely failed it's just saying that the heart is failing its ability to kind of properly do its function so when this guy goes jogging because he has a restricted blood supply because it the hardest experiencing ischemia down down I guess downstream from this stenosis that's why there's heart failure it's not able to deliver now this heart failure which is due to the ischemia and this which is due to this stenosis you would call this heart failure due to coronary artery disease let me write it we talked about battle-ax in two videos ago coronary coronary coronary artery disease which is really just kind of a an imp area of the hearts function because of reduced blood supply because of a narrowing in a blood vessel which restricts the blood supply ischemia that is coronary artery Dee's disease and because of coronary artery disease when this cell when this muscle cell and the heart really needs to pump hard maybe because someone's going up a hill or climbing stairs it's not able to do it because it's not getting enough oxygen and that inability to properly for the heart not just the cell but for the whole heart this is just one of many cells that maybe we won't be able to pump properly for the entire heart to not do its job that is heart failure now you've also probably heard the terms coronary heart disease coronary heart heart disease or maybe just heart disease heart disease these three things are all the same thing these are all the same they all imply some type of narrowing or stenosis of arteries that leads to ischemia reduced blood flow so that the heart can't function as well as that otherwise could now the last thing I want to focus on and I talked a little bit about it in the last video is the idea of an infarct or an infarction these are kind of funny words to say so I'll write it over here so an infarct infarct or infarction so in the example I've drawn so far this this cell for example maybe does not get enough oxygen especially once the person is going upstairs and all of that to properly help to properly contract and help the heart actually pump but it's not dead it's still getting some base level of oxygen less because of the stenosis and the ischemia but it still gets some oxygen and we saw in the video on myocardial infarction or the video on heart attacks that sometimes one of these plaques might become unstable and they break off and then you have a complete you have a complete blocking of a vessel a complete blocking of a of an artery right here and we saw in the last video we call this blocking what's called an embolism and if it's due to if it's an embolism is the general for something that floated around and then eventually blocks a vessel and if it was due to kind of a released plaque that also had clotting factors around it after it got released that we would call this a thromboembolism and this would completely this would this would reduce the the blood flow so much this reduces the blood flow so much maybe a little bit might be able to leak around but it reduces it so much that the cells downstream from this actually die so you actually have the cell right over here and this cell will die because it's not even it might get very little blood or no blood at all so it's not getting enough oxygen to actually survive and when you have dead tissue when you have dead tissue that's due to a loss of oxygen this is an infarct dead tissue due to a loss of oxygen the process of it becoming dead tissue due to a loss of oxygen is an infarction and this infarction this dead tissue due to loss of oxygen in in in the myocardium in the muscle tissue of the heart so now of a sudden you have muscle tissue in the heart that's beginning to die this is a heart attack this is a myocardial infarction so hopefully that clarifies things a little bit