Risk factors for coronary artery disease | Circulatory System and Disease | NCLEX-RN | Khan Academy



so we know that coronary artery disease is when you get this build-up of fatty plaques in different places in your coronary circulation so for example I'm drawing in bits of this plaque right so this atherosclerosis and these are going to cause coronary artery disease right these are going to lead to downstream pathologies diseases like stable angina and an acute coronary syndrome so we know that this is really bad right we don't really want coronary artery disease to be happening in our bodies so so is there anything we can do about this is there anything that we can do to stop or prevent these plaques from building up in our arteries and in fact yes yes there are some things we can do and and you know we didn't always know that there was something we can do way back in the in the 1940s I believe it is the the late 1940s there is a study done called the Framingham Heart Study and the Framingham Heart Study was pretty revolutionary it it showed that there were risk factors for developing coronary artery disease and so why is that revolutionary well it means that there's something we could potentially do to reduce the incidence of coronary artery disease and and that's really good because coronary artery disease is the leading cause of death in men and women in the u.s. so all this all this talk about risk factors what what exactly is a risk factor well a risk factor is something that predisposes you to something else so for example you could say that buying buying an iPhone 6 is a risk factor for not having very much money left in your wallet or playing playing ice hockey against Canadians is a risk factor for losing the hockey game if you're on the other team but to bring it back to something more relevant something like hypertension would be a risk factor for coronary artery disease because all of the stress that that pathologically high blood pressure puts on your vessels would predispose you to developing coronary artery disease so the Framingham Heart Study showed us that there are two major types of risk factors modifiable risk factors and non-modifiable risk factors and this is actually really important it kind of means that we could do something we could modify something about our lives to lower our risk of coronary artery disease but the flipside is that there are non modifiable things too so no matter what we do we can't change these things about our lives so let's take a look at the major ones so what's an example of a non modifiable risk factor well age age is a risk factor because you can't really change how old you are and so in coronary artery disease for men being 45 years or older sort of puts you in a higher risk bracket than being younger than that and and for women it's over 55 and and it's not like 45 and 55 they're not these magic numbers that all of a sudden once you turn 45 on the day of your 45th birthday you're just more prone to developing these plaques it's just that by the time you reach about 45 in men and 55 and women enough time has gone by in your life for you to get a significant amount of buildup so again I want to stress at a thorough Sclerosis the underlying sort of plaque forming process behind coronary artery disease that's that's a chronic condition it develops over a long period of time and so once you hit about 45 years old and men 55 and women that's been you know a pretty good amount of time for the plaques to have built up and so immediately you should have another question I mean if you look at the what we've just written down right let me let me highlight this for you but we say men have a higher risk after 45 years and females have a higher risk after 55 years well that's a pretty huge difference that's ten years I mean you think back to ten years ago and there was no such thing as an iPhone and I can't even imagine that but so ten years is a long time and so why are men at a higher risk then and you know the answer is a bit multifactorial there's a couple of reasons for example men tend to have a less healthy cholesterol profile in their blood compared to women and it's thought that the higher levels of estrogen that women have contribute to the better profile of cholesterol that women have and another interesting reason might be that studies show that women tend listen to their doctors more when their doctors recommend lifestyle changes so the lowered sort of incidence of cardiovascular disease might be a reflection of that so what else is non-modifiable well your family history for example if someone in your family a first-degree relative maybe had coronary heart disease or any other type of heart disease you would probably be at increased risk of also developing heart disease and there's nothing sort of magical about that it's just that you would share a lot of genetic material and we know that coronary heart disease has a lot of genetic influence to its development so one more non-modifiable one I'll touch on is is ethnicity for example certain ethnicities are indirectly at a higher risk people of African descent tend to have higher rates of hypertension than people of non African descent and hypertension is a really well characterized risk factor for development of coronary artery disease okay so those are the major non-modifiable risk factors but what are some of the modifiable risk factors I mean we know that coronary artery disease is not what we want well what can we do about it what exactly can we do to to prevent it or at least reduce the incidence or or reduce the development of it what can we do well there's quite a lot of things we can do actually I mean none of them will necessarily completely prevent us from developing atherosclerosis or at the hromas plaques but you know if we know that there is something we can do then let's do that so let me make some room here and I'll do them in different colors this time they'll do the modifiable one's over on this side so high blood cholesterol levels especially LDL the bad cholesterol the so called bad cholesterol I mean we know that a huge part of development of atheroma is of these plaques is is you know the buildup of cholesterol in the walls and the damaged walls of blood vessels right so you know it makes sense well if I have more LDL if I have more this bad cholesterol probably more of it's going to build up in the walls wherever there's damage and and that's what we see in the studies so cholesterol high levels of LDL cholesterol is one of the key risk factors the key modifiable risk factors high triglycerides or high levels of fat free fatty acids because because high levels of certain types of fat and I won't get into all the details now but high levels of certain types of fat will increase levels of other enzymes that increase plaque formation and I know that sounds a bit sort of a runaround but but that's the mechanism that we we understand and by the way I mean I'm saying high levels of this high levels of that but what I'm meaning is in your blood so if you have high levels of LDL in your blood high levels of triglycerides in your blood that's what I mean so just keep that in mind what else high blood pressure or hypertension because we know that high blood pressure will damage blood vessel walls with shear stress right the blood will sort of bang against the blood vessel wall with so much force that it sort of causes damage to the blood vessel wall and then that's when the the LDL cholesterol gets in there and starts the plaque buildup right so that's why hypertension high blood pressure is is risk factor now here's a big one this is this is probably the biggest one and and it's cigarette smoking and you've probably heard this already you probably know that smoking damages your blood vessels and smoking is bad for you but you know it really is really bad for you and so it turns out that actually quitting smoking is the single biggest thing that you can do to prevent develop development of coronary artery disease to prevent plaque formation so the reason for this right is because remember the whole sort of underlying issue in the first place is when you get damage of the blood vessel wall right so you damage the wall then the the cholesterol can jump in there and have a big party and create a huge plaque well when you smoke a cigarette you are ingesting toxins right and the toxins will get into your blood and they will directly damage your blood vessel walls and you know we're talking about it in terms of its relevance to the heart right now but it can happen anywhere in your body right and so cigarette smoking these these toxic substances will damage your blood vessels and you will develop a thoroughness so cigarette smoking is the single biggest risk factor and I know it sounds like I'm going on and on and on about this but it really is that important to to cut that out so so that's that so what's another big one another big one is is diabetes and and I think most of us know that diabetes is sort of a disease caused by excess sugar excess glucose that's sort of floating around in your blood and sort of wrecking havoc on on your different sort of vascular systems and one of the problems that diabetes causes is that it damages your blood vessels because what happens is the the little glucoses that are all floating around unregulated in your blood they they bind on to the sides of your blood vessels and they make them stiff and damaged a process called glycosylation and you know I hate to be the dead horse but you know we've talked about how the the blood vessel damage is what sort of predisposes you sets up coronary artery disease and plaque formation and it's really the same sort of process after you get that blood vessel damage and diabetes so these are sort of the underlying modifiable risk factors right because there's something we can do about our blood sugar there's something we can do about our cholesterol and same goes for our our fats and and our blood pressure and and cigarette smoking we can stop smoking so these are really the underlying modifiable risk factors but you know in terms of your lifestyle and what can you do with your lifestyle other than sort of these dietary changes is you can increase your level of physical activity a reasonable level of physical activity every week or every day can dramatically reduce your risk of developing coronary artery disease and that's because when you exercise right when you exercise you you improve the levels of glucose in your blood and you improve your cholesterol profile and you use up a lot of your fats and you lower your blood pressure and you know just going by the numbers by the statistics here if you were an exerciser then you're less likely to be a smoker and so just by getting exercise into your week you're all of a sudden reducing all of these modest we'll risk factors for coronary artery disease so if you're obese or if you have a distinct lack of physical activity then all of that sort of plays in and increases your overall risk again on top of these other modifiable risk factors so that's really all I wanted to say about non-modifiable and modifiable risk factors but there is one more sort of interesting little tidbit that I have to drop on you you know one of the reasons for for acute coronary syndrome to happen is is atherosclerosis right it's buildup of these fatty plaques but another reason you might get acute coronary syndrome is due to cocaine use cocaine or amphetamine use so I thought I'd just touch on why because this really is supposed to be both about coronary artery disease and acute coronary syndrome what cocaine can do to your coronary vessels is it can cause them to vasospasm now vasospasm what what the heck does that mean well it means that it causes your coronary arteries to sort of clamp down and close off and by the way I'm not I'm not writing cocaine and white for any particular reason in case you were wondering just putting that out there so that's obviously not gonna let blood through right so in that way it sort of approximates a plaque it's similar to a plaque in that it can compromise blood flow downstream and that's how it causes acute coronary syndrome so that's probably another thing to not do

19 comments

  1. And this kids is how i met coronary artery disease. 😂I hear TED from How I met your mother giving me a lecture and it is …. wait for it… incredible. Thanks khan academy! 😊

  2. Hi, can you please link the research papers . Pretty please . Especially when you coated on how women tend to listen to doctors advice as compared to men @khanacademymedicine .

  3. i dont know how to thank you really ,if someday i will be agood doctor its really belong to your brilliant videos and explanations … big thanx 💕

  4. great info.

    my triglycerides level is 411 what can i do about it. i smoke one pack a day and i drink a litter of beer a day to help me sleep. took this blood chemistry thing and saw the results. i want to change my lifestyle a bit afraid of this above normal results.

    thanks for this post. 🙂

  5. Clear, straight to the point. Great explanation in all your videos! Thanks so much. FYI, studying for NBDE. 

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