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

– So we know that coronary artery diseaseis when you get this
build up of fatty plaquesin different places in
your coronary circulation,so, for example, I’m drawing
in bits of this plaque, right?So bits of this atherosclerotic plaquebuilding up in different parts
of your coronary vessels,and these are going to cause
coronary artery disease, right?These are going to lead
to downstream pathologies,diseases like stable anginaand acute coronary syndrome,so we know this is really bad, right?We don’t really want
coronary artery diseaseto be happening in our bodies,so is there anything we can do about this?Is there anything that we can doto stop or prevent these plaquesfrom building up in our arteries?And, in fact, yes, yes there
are somethings we can do,and we didn’t always knowthat there was something we can do. Way back in the 1940s, I
believe it is, the late 1940s,there’s a study done called
the Framingham Heart Study,and the Framingham Heart Study
was pretty revolutionary. It showed that there were risk factorsfor it developing coronary artery disease,and, so, why is that revolutionary?Well, it means there’s somethingwe could potentially do to reducethe incidence of coronary artery disease,and that’s really goodbecause coronary artery diseaseis the leading cause of death
of men and women in the U. S. ,so all this talk about risk factors. What exactly is a risk factor?Well, a risk factor is somethingthat predisposes you to something else,so, for example, you could say thatbuying an iPhone six is a risk factorfor not having very much
money left in your wallet,or playing ice hockey against Canadiansis 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 factorfor coronary artery diseasebecause all of this stressthat pathologically high blood
pressure puts on your vesselswould predispose you to developingcoronary artery disease,so the Framingham Heart Study showed usthat 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 we could do something,we could modify something about our livesto lower our risk of
coronary artery disease,but the flip size is 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 factorbecause you can’t really
change how old you are,and, so, in coronary
artery disease for menbeing 45 years or oldersort of puts you in a higher risk bracketthan being younger than that,and for women it’s over 55,and it’s not like 45 and 55,they’re not these magic numbersthat all 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 timeyou reach about 45 in men and 55 in womenenough time has gone by in your lifefor you to get a significant
amount of buildup,so, again, I want to stress
that atherosclerosis,the underlying, sort of,
plaque forming processbehind coronary artery disease,that’s a chronic condition. It develops over a long period of time,and, so, once you hit abut 45
years old in men, 55 in women,that’s been a pretty good amount of timefor the plaques to have built up,and, so, immediately, you
should have another question. I mean, if you look at what
we just written down, right?Let me highlight this for you,but we say men have a
higher risk after 45 yearsand females have a higher
risk after 55 years,well, that’s a pretty huge difference. That’s 10 years. I mean, you think back to 10 years ago,and there was no such thing as an iPhone,I can’t even imagine that,but, so, 10 years is a long time,and, so, why are men
at a higher risk then?And, you know, the answer
is a bit multi factorial. There’s a couple of reasons. For example, men tend to havea less healthy cholesterol profilein their blood compared to women,and it’s thought that the
higher levels of estrogenthat women have contribute tothe better profile of
cholesterol that women have,and another interesting reason might bethat studies show that women tendto listen to their doctors morewhen their doctors
recommend lifestyle changes,so the lower incidence
of cardiovascular diseasemight 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 riskof also developing heart disease,and there’s nothing sort
of magical about that. It’s just that you’d share
a lot of genetic material,and we know that coronary heart diseasehas a lot of genetic
influence to its development,so one more non-modifiable one
I’ll touch on is ethnicity. For example, certain ethnicitiesare indirectly at higher risk. People of African decent tend to havehigher rates of hypertensionthan people of non African decent,and hypertension is a
really well characterizedrisk factor for development
of coronary artery disease. O. K. , 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 diseaseis not what we want. Well, what can we do about it?What exactly can we do to prevent it,or at least reduce the incidence,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 necessarilycompletely prevent us from
developing arteriosclerosisor atharomas, plaques,but, you know, if we know that
there’s 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. I’ll do the modifiable
ones over on this side,so high blood cholesterol levels,especially LDL, the bad cholesterol,the so called bad cholesterol. We know that a huge part
of development of atheroma,of these plaques is the
build up of cholesterolin the walls and the damaged
walls of blood vessels, right?So, it makes sense,
well if I have more LDL,if I have more of this bad cholesterol,probably more of it is going
to build up in the wallswherever there’s damage,and that’s what we see in the studies,so cholesterol, high
levels of LDL cholesterolis one of the key risk factors,the key modifiable risk factors. High triglycerides, or high
levels of fat, free fatty acidsbecause high levels of
certain types of fat,and I won’t get into all the details now,but high levels of certain types of fatwill increase levels of other enzymesthat increase plaque formation,and I know that sounds
a bit of a run around,but that’s the mechanism
that we understand,and, by the way, I’m sayinghigh 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 hyper tension,because we know that high blood pressurewill damage blood vessel walls
with sheer stress, right?The blood will sort of bang againstthe blood vessel wall with so much forcethat it causes damage to
the blood vessel wall,and that’s when the LDL cholesterolgets in there and starts
the plaque buildup, right?So that’s why hypertension,
high blood pressure,is a risk factor. Now here’s a big one. This is probably the biggest one,and it’s cigarette smoking,and you’ve probably heard this already. You probably know that smoking
damages your blood vesselsand smoking is bad for you,but it really is really bad for you,and, so, it turns out that
actually quitting smokingis the single biggest
thing that you can doto prevent development of
coronary artery disease,to prevent plaque formation,so the reason for this, right?Is because remember the wholeunderlying issue in the first placeis when you get damage
of the blood vessel wall,so you damage the wall,then the cholesterol can jump in thereand have a big party,and create a huge plaque. Well, when you smoke a cigarette,you are injesting 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 termsof it’s relevance to the heart rate now,but it can happen anywhere
in your body, right?And so cigarette smoking,these toxic substances will
damage your blood vessels,and you will develop atharomas,so cigarette smoking is the
single biggest risk factor,and I know it sounds likeI’m going on and on and on about this,but it really is that
important to cut that out,so that’s that. So what’s another big one?Another big one is diabetes,and I think that most
of us know that diabetessort of is a disease
caused by excess sugar,excess glucose that’s sort of
floating around in your bloodand sort of wrecking havoc onyour different vascular systems,and one of the problems
that diabetes causesis that it damages your blood vesselsbecause what happens
is the little glucosesthat are all floating around
unregulated in your blood,they bind onto the sides
of your blood vessels,and they make them stiff and damaged. A process called glycosylation,and I hate to beat a dead horse,but do you know we’ve talked abouthow the blood vessel damage
is what predisposes you,sets up coronary artery
disease and plaque formation,and it’s really the same sort of processafter you get that blood
vessel damage in diabetes,so these are the underlying
modifiable risk factors, right?Because there is something we can doabout our blood sugar,there’s something we can
do about our cholesterol,and same goes for our fats,and our blood pressure,and cigarette smoking,we can stop smoking,so these are really the underlying
modifiable risk factors,but it terms of your lifestyle,and what can you do with your lifestyleother than these dietary changesis you can increase you
level of physical activity. A reasonable level of physical activity,every week or every day,can dramatically reduce your riskof developing coronary artery disease,and that’s because when
you exercise, right,when you exercise you improve the levelsof 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,than 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 thesemodifiable 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 plays in and increasesyour overall risk again on top ofthese other modifiable risk factors,so that’s really all I wanted to say aboutnon-modifiable risk and
modifiable risk factors,but there is one more
interesting, little tidbitthat I have to drop on you. One of the reasons for acute
coronary syndrome to happenis atherosclerosis, right?It’s buildup of these fatty plaques,but another reason why you mightget acute coronary syndrome
is due to cocaine use,cocaine or amphetamine use,so I thought I’d just touch on whybecause this really is
suppose to be both aboutcoronary artery disease and
acute coronary syndrome. What cocaine can do to
your coronary vesselsis it can cause them to vasospasm. Now vasospasm, what the
heck does that mean?Well, it means that it
causes your coronary arteriesto clamp down and close off,and by the way I’m not
writing cocaine in whitefor any particular reason
in case you were wondering,just putting that out there,so that’s obviously not going
to let blood through, right?So, in that way it sort
of approximates a plaque. It’s similar to a plaque in that itcan compromise blood flow downstream,and that’s how it causes
acute coronary syndrome,so that’s probably
another thing to not do.