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Flashcards in Unit Test 2 Deck (162):

what are the 3 major causes of death in the Canada?

1. cancer
2. CAD
3. stroke
stroke and CAD together amount to more than cancer


stress test

ECG measured on a treadmill at different intensities and used as a diagnostic tool for CVD



Coronary Heart Disease
- coronary heart damage, the largest portion of deaths attributed to this part of CVD (42%)
- artery damage, not being able to deliver enough O2 to heart muscle


mortality from heart disease in the US patterns

it has decreased to 59% since the 1960s
- primarily due to smoking awareness/prevention, better technology and medicine for treatment and diagnosis
- awareness of risk factors and people are surviving heart attacks more


CHD is the #_ cause of death in the US? in Canada?

#1 in both
accounts for about 20% of deaths annually
also costs a lot of money



acute myocardial infarction
heart attack


what proportion of heart attacks are sudden?

half; no signs or symptoms; people die


male vs female risk for CVD

males have greater risk up to age 74
females have greater risk than men after age 50 (post menopause, atherosclerosis takes time to develop but is speed up by lack of estrogen present)


ischemic heart disease

anything that causes a decrease in blood flow


how is all cause mortality described?

as death rates in the population


male vs female life expectancy

- females live longer than males on avg


life expectancy

the number of years you're expected to live from the year you're born
- on average, half lives to be above this and half dies before then
- can also be measured from different points in life
- max is 122 years


Health Adjusted Life Expectancy (HALE)

the number of healthy years you're living
- PA can improve this
- canada's is 10th in the world: we drive everywhere and it;s killing us
- in Canada it's about 72


physical inactivity as a risk factor for all cause mortality

wasn't a problem before because people had to be active as a part of their daily lives at work, they had non processed food
- they also died of infectious disease around age 40 before chronic disease was an issue


disturbing trends in PA and the impact it has on overall health/all cause mortality

with these large amounts of screen time, the resulting physical inactivity leads to increased levels of obesity, which is linked to CVD


trends for countries with longer life expectancies

mostly European countries with more active transportation
- they also have lower obesity rates due to their being more physically active


what is the relationship between obesity prevalence and active transportation?

an inversely proportional relationship
- when people are more physically active, they are less obese


what proportion of deaths do chronic diseases contribute?

(only developed nations really deal with chronic disease because undeveloped nations are dying from infectious disease as they have inadequate healthcare)
- almost half of these are due to CVD


PA and harvard alumni study

- death rates were 25-30% lower in alumni expending 2000kcal or more per week
- active men gained 1-2 years of life for every hour of PA they did per week


person years

the number of people in your study times the number of years they were in your study


where is the greatest reduction in overall death risk seen?

- from people going from sedentary to lightly active lifestyles
- generally a drop and plateau


moderately fit men and women have __ reduction in risk of all cause mortality compared to unfit

moderately fit people have a 50% reduction in risk


what is a common relative risk in studies on PA and mortalitu

a RR of 0.5 is common; it means that you half the risk or reduce it by 50%


risk is reduced another __% in highly fit compared to moderately fit individuals

10-15% lower in highly fit


with regards to when you're physically active during your life, how does risk look in terms of all cause mortality?

- the risk b/w people who were active their whole lives and those who became active later in life was about the same


dose-response relationship b/w PA and mortality?

yes, reduction in risk seen largest by people who meet PA guidelines and are most active


what percentage of Canadians are meeting the PA guidelines?



how does age influence our PA rates? why?

as we get older, our PA rates decrease
- because physiological changes make this more difficult
- possibly bc of biological reasons as this trend is also seen in monkeys


coronary risk factors def'n

characteristics that tend to increase the chances of developing coronary artery disease
- usually general narrowing/ blocking of arteries


major modifiable risk factors for CHD

1. tobacco use
2. hypertension
3. high blood cholesterol (LDL)/ lipids
4. physical inactivity
5. overweight/obesity
6. diabetes
7. unhealthy diet (incl alc abuse)


major non-modifiable risk factors for CHD

- age: older more risk
- sex: male early in life, females later in life
- race
- genetic predisposition


host susceptibility

can be measured by the number of non-modifiable risk factors that someone has


widow maker artery

anterior interventricular branch
aka the left anterior descending
- because ventricles need to pump blood to body and it can't if it has no blood supply itself



the anatomical changes underlying the condition
- structure change and result in condition
- use to come up with diagnosis



the development of the condition and how the disease progresses


symptoms reflect ___ and result from ___

pathology; etiology


symptoms of MI

- often unrecognized and are confused w heartburn
- 21% of heart attacks can be silent and thus left untreated
diff for men than women:
men- classic signs usually after physical activity
women- usually after emotional stress, usually don't go to doctor in time or have higher pain tolerance



often etiology for heart disease
- the build up of calcium and fats inside the inner walls of an artery causing it to become narrowed
- an intimal disease in intima layer



- stiffening of arteries
- happens in CT layers of artery



narrowing of a structure


where in vessels is atherosclerosis usually found?

often in vessels that bifurcate or bend


intravascular ultrasound (IVUS)

- putting ultrasound probe through blood vessel and it sends a radio signal from the middle of the tube
- allows us to see plaque and how thick it us


cardiac catheterization

could insert catheter into brachial or femoral artery (pref. femoral since it's larger and can still allow blood flow around the catheter)


coronary angiogram

- cheaper and quicker than catheterization, hits lots of vessels at once
- radio-opaque dye injected into the coronary arteries and gives picture of obstruction where you don't see the black and an artery should be there (X-ray)
- you can only see black areas of reduced blood flow, but can't see the stenosis itself


methods of screening for atherosclerosis

cardiac catheterization
coronary angiogram
intraventricular ultrasound (IVUS)


using a stent to treat atherosclerosis

inflating a balloon on the end of a catheter in an area where stenosis is and balloon pushes fat out of the way and inflates the stent which holds lumen open


coronary artery bypass graft (CABG)

if there are multiple stenosed regions, they can do bypass surgery which often uses a subclavian branch of an artery and attach it to the area the artery is blocking flow to using a vein from the leg


there are 2 types of stenosis of arteries:

fixed obstructions
dynamic blockages


fixed obstructionof a coronary artery

ex. atherosclerotic plaque that blocks blood flow through artery, most likely to result in heart attack if clot ruptures and blocks off vessels (the results from an inflammatory response)


dynamic obstruction of a coronary artery

caused by coronary arterial spasm that decreases blood flow to heart tissue
- typically transient, not lasting long enough to cause heart attack
- smoking, stimulant drugs, and diabetes can cause spasms


thrombus (clot) formation

at a bifurcation, vessel diameter gets smaller and endothelial wall deals with more stress at the bifurcation
- when plaque has ruptured, a clot forms, blocking blood flow so it can't move through the vessel


turbulent flow theory of artery injury

at a bifurcation, the fastest moving cells are in the centre of the blood vessel and so they hit the area where the vessel splits, causing more damage due to the sheer stress put on endothelial cells


vasomotor tone

- signals changes that cause blood vessels to change diameter
- cytosolic calcium stimulated release of NO caused by sheer stress on endothelium, triggers smooth muscle in media layer to dilate


nitric oxide (NO)

- a potent vasodilator, inhibits platelet adhesion and activation therefore also inhibits clotting
- antiflammatory agent: inhibits adhesion of leukocytes to endothelial surface when there's damage to endothelium
- has short half life so doesn't stay in circulation long



- the building up of plaque
- begins w endothelial disruption caused by intimal injury
- platelets adhere to collagen at site activating fibrinogen
- fibrinogen increases platelet aggregation and releases platelet derived growth factor (PDGF)
- macrophages eat damaged cells, debris and oxidized LDL to make fatty streaks
- smooth muscle cells and fibroblasts migrate to intima to make fibrosis (cap)
- lipid deposits accumulate to increase stenosis


factors that cause endothelium injury

- tobacco
- homocysteine
- oxidized LDL stimulates monocyte secretion
- high blood glucose



an intermediate AA
- present in people who eat a lot of protein, males, older people, sedentary, environmental toxins
- high levels increase risk, starting to breakdown an AA
- decreased by folic acid, exercise, vitamins B6 and B12


why is high blood glucose a problem

cells keep trying to take up the glucose, then it gets added to proteins which make them sharp and dysfunctional and causes endothelial damage


when do symptoms of atherosclerosis appear?

when the blockage reduces blood flow by about 80%


myocardial ischemia

inadequate oxygen supply to part of the heart caused by impaired blood flow
- results in angina



a reduction in blood flow to anywhere in your body leading to insufficient O2 delivery to tissues



symptoms of heart attacks without actually causing tissue damage


symptoms of ischemia

chest, arm neck and jaw pain, indigestion type pain
- people take nitroglycerin which stimulates release of NO and increases blood flow again


secondary prevention vs primary prevention

primary: trying to keep from getting the disease
secondary: trying to keep the symptoms from getting worse


does primary prevention of atherosclerosis exist?
risk factors of atherosclerosis?

not really, 1 in 6 teenagers has coronary plaques; we can't really stop it but we can slow it down
risk factors: smoking high BL, diet high in saturated fat and cholesterol


what types of stenoses cause most infarctions?

low grade ones, most people who have heart attacks have less than 50% stenosis and are therefore asymptomatic ; when more stenosed, the plaque has a strong fibrous cap and risk of rupture is lessened


what percentage of first heart attacks are fatal?

- a lot of people don't know anything is wrong until they die from a heart attack; people don't usually get cardiac checkups


characteristics of plaque prone to rupture

- thin fibrous cap
- lipid, macrophage rich
- smooth muscle poor


how do we know about the relationship between PA and CHD?

evidence from:
- occupational studies
- leisure time PA studies
- studies of fitness


london bus study

- showed effects of occupational PA on CHD
- bus drivers had high BP, were obese and once there were factored out, there was still reduced risk for conductors compared for drivers
- when conductors had heart attacks, they were less severe


problems with PA studies

- might not measure every variable
- can't determine cause and effect w cross sectional or retrospective
- confounders
- inaccuracy of medical/autopsy records/ recall of habits by family members


physical fitness and its relationship to CVD mortality

more strongly related to reduce CHD than other estimates of PA
proof: greatest reduction in risk for those who are more physically fit


nurses health study

a large scale population study on nurses and PA rates
- when family history of CDV isn't a factor, risk goes down, thus deeming physical inactivity a risk factor
- supports that PA works in both women and men to prevent CVD


CVD risk in women and men and PA

- there was originally thought to be no relationship b/w PA and CVD in women
- however, PA reduces the risk of CVD to a similar extent in women as in men


PA and its influence on other CAD risk factors

it can reduce independent risk factors for CHD but also other risk factors like high BP, weight, lipids


PA and risk of recurrent heart attack

although there is a reduction in CAD mortality with exercise rehab, there is no reduction in risk of having another non-fatal MI


Mill's Canons for CVD
(temporal sequence, strength of assoc, consistency)

temporal sequence: yes
strength of association: risk is 2x higher if inactive; also note 2000kcal/week protection against CVD
consistency of results: yes


fibrinolytic factors

break down clots


biological plausibility for PA to have an effect on CVD risk

increases HDL cholesterol and fibrinolytic factors
reduces BP, TG, body fat, blood coagulability and MVO2 (heart is getting more efficient and so needs less O2 during PA)



myocardiac VO2: the amt of oxygen needed for heart to survive to do work
- decreases with exercise training because heart is getting to be more efficient and requires less O2


functional adaptation

we get healthier endothelium and the release of things like NO contribute to better vasodilation


structural adaptation

over time, remodelling by significantly increasing the size of your arteries (diameter, thickening)


the relationship between functional adaptation and structural adaptation

starting by relying more on functional adaptation. then, as structural adaptation increases, then we rely less and less on functional adaptation


cerebrovascular disease and stroke definition

a stroke is the loss or impairment of bodily function resulting from injury or death of brain cells after insufficient blood supply
- results from hypoxia (inadequate oxygen delivery) caused by ischemia



inadequate oxygen supply


warning signs of stroke

1. weakness
2. trouble speaking
3. vision problems
4. headache
5. dizziness


what is the mnemonic for the public to recognize the stroke?

face drooping
arm weakness
speech difficulty
time to call 911


types of stroke

- thrombotic or embolic
- also TIAs
- subarachnoid or intracerebral


ischemic stroke

- interruption of blood flow to the brain due to a blood clot or possibly swelling of the brain
- 80% of strokes are ischemic
- atherosclerosis usually involved
- either thrombotic or embolic


thrombotic stroke

category of ischemic stroke
- a blood clot that forms in an artery directly leading to the brain
- more typical


embolic stroke

category of ischemic stroke
- clot develops somewhere else in the body and travels through the blood stream to the brain
- usually in older people if someone falls and gets injured, the clot forming might move to the brain and cause a stoke
- also can be caused by irregular heart rhythm (AFib) where blood spends too much time in ventricles and clots



transient ischemic attack
- similar to angina in the heart, called a mini stroke where O2 delivery to brain is interrupted temporarily but no cells die so it's not really a stroke
- symptoms similar to ischemic stroke except they go away w/in a few hours
1/3 of people who have a TIA have a stroke within 5 years therefore it puts you significantly at risk


hemorrhagic stroke

caused by uncontrolled bleeding in the brain when a blood vessel bursts
- bleeding interrupts normal blood flow and by flooding the brain (also lots of pressure), kills brain cell because they damage the brain cell env't
- 20% of strokes
2 types: subarachnoid or intracerebral hemorrhage


subarachnoid hemorrhage

a category of hemorrhagic stroke
- uncontrolled bleeding on the surface of the brain in the area between the brain and skull


intracerebral hemorrhage

a category of hemorrhagic stroke
- occurs when an artery deep within the brain ruptures


types of hemorrhage

both types of hemorrhage can cause hemorrhagic stroke
- therefore if you take aspirin, it thins your blood and you'll bleed out
- aneurysm
- AVM (atriovenous malformation)



a weakened area in the blood vessel wall of he blood vessel that fills with blood and bulges
- turbulent flow is here now and puts blood at a greater risk of clotting



atriovenous malformation
- a malformation of the brain's blood vessels usually present at birth, causing the artery walls to be weak and could break over time


how much of a problem is cerebrovascular disease and stroke?

3rd leading COD is US
5th leading in Canada (5%)


incidence of stroke

10-15% higher in women than in men
- maybe bc of hormones released during pregnancy or bc of loss of protective estrogen bc of menopause


why does someone usually do PA after having a stroke?

rehab probably, rather than prevention


non modifiable risk factors for stroke

- age: greater than 65 and increases exponentially after this
- gender: before menopause women have decreased risk but after, their risk is greater than that of men
- family history: if someone has a stroke before a certain age, it's likely a result of genetics
- ethnicity: First Nations and South Africans have higher incidence
- PRIOR STROKE or TIA puts you at greatest risk of having another


modifiable risk factors for stroke

- high BP, blood cholesterol (LDL)
- heart disease, atrial fibrillation (causes 50% of strokes)
- diabetes, being overweight
- excessive alc consuption
- physical inactivity
- smoking, stress


what is the #1 modifiable risk factor for stroke

- an estimated 45% of people have high BP


how does age influence someone's risk of having a stroke?

after age 55, risk doubles with each decade


classifications of blood pressure

stage 1 hypertension
stage 2 hypertension


normal blood pressure




systolic: 120-139
disatolic: 80-89


stage 1 hypertension

systolic: 140-159
diastolic: 90-99


stage 2 hypertension

systolic: >160
diastolic: >100
- pretty dangerous


systolic pressure

the peak pressure in arteries during ventricular ejection


diastolic pressure

the pressure in the arteries during ventricular relaxation


what happens when someone's systolic blood pressure is less than 100mmHg

they have almost no risk of CVD
- they also faint a lot if they don't have sufficient oxygen delivery to body tissues


how does high blood pressure work?

- when arterioles constrict, the heart has to work harder to force the blood through and often becomes enlarged which is not good
- when we have lots of resistance in the system, it's harder to move blood through, arteries stiffen and increases resistance more


framingham results re: BP and stroke risk

systolic BP over 150 doubles stroke risk
which is 4x that of risk of heart disease


physiological effects of cigarette smoking

- heart rate increases: NE release causes increasing resting heart rate but heart isn't getting any more O2 supplied bc body is at rest
- blood O2 carriage decreases: Hgb has a higher affinity for carbon monoxide than O2
- blood clots form: nicotine causes coagulation of blood which can cause coronary thrombosis or stroke


effects of nicotine

- increases BP
- causes heart to work doubly hard (increases contraction force and stroke volume)
- dysrhythmias by stimulation of ectopic pacemakers
- increase in both plasma FFAs and platelet adhesiveness, predisposing someone to atherosclerosis


smoking and how it increases stroke

- in general, smoking more than a pack a day has twice the risk of a heart attack and increases risk of stroke 5x over someone who doesn't smoke
- when combined with high blood cholesterol and hypertension, smoking increases risk of stroke by 7x (double that of MI)


physical activity and risk of stroke trends

no trends,
there is no clear associations that show PA as a preventative for stroke, but there probably is some protective effect


what do case control studies show in terms of the association between stroke and PA?

- when comparing people who've had a stroke to those who haven't, a lifelong reduction in risk is present for those who have been physically active throughout their lifespan (50% more)
- also the greatest reduction in risk is seen in those who are active more recently as well


study results re: PA exercise frequency, intensity and amount on stroke

Harvard alumni study shows that:
- lowest amount of PA has greatest reduction in risk regardless of other factors
- in terms of PA frequency and intensity, PA acts as an effect modifier on stroke where it improves certain risk factors that decrease the likelihood of having a stroke


Nurses' health study results on stroke

- all women study looking at if doing a little PA would reduce risk
- found that the more PA and at greater intensity had the greatest reduction in risk


Mill's canons for stroke and PA

- temporal sequence: yes, PA later in life was still effective
- **strength of association: risk reduction 30-60%
- consistency of results: yes most studies show reduction in risk, consistent w diff pop also
- does response: not as clear; extra benefit of vigorous controversial opinion
- biological plausibility: yes. PA reduces risk factors, blood clotting, etc


how are people categorized into levels of blood pressure if systolic and diastolic BPs are part of different classifications

have to put them in whichever is higher because you don't want to underestimate someone's hypertensiveness


Korotkoff sounds

- first heard when brachial artery is partially open: pressure at this point is systolic
- when sound stops, brachial artery is mostly open, the pressure at this point is diastolic


cause of hypertension

cause is unknown in 95% of cases


prevalence of hypertension

NHANES III study says that prevalence is 20%, most people don't know they have it though so it's estimated to be about 50% of Canadians


methods for primary prevention of hypertension

- normal body weight
- reduce dietary sodium intake so that you can expel water
- regular aerobic PA
- limit alcohol consumption
- maintain adequate dietary K+
- consume diet that would prevent atherosclerosis


drugs for treatment of hypertension

generally either decrease HR or help eliminate fluids from body
- diuretics
- SNS receptor blockers
- ACE inhibitors
- calcium channel blockers
- also a combo of some of the above


fundamental regulatory equation of the circulatory system:

flow/cardiac output (Q) = change is pressure / resistance (or total peripheral resistance- TPR)
- anything that affects cardiac output or TPR will effect arterial pressure


contributing factors to arterial pressure

- total blood volume (more vol=more pressure)
- rate of blood flow (CO)
- blood vessel diameter (bc flow= length of tube X viscosity of blood/radius^4)
--- arteriolar resistance is important because of total cross-sectional area in the body


SNS impact on BP

sympathetic nervous system (SNS) increases BP
- SNS nerves release NE, adrenal glands release epinephrine
- both bind w adrenergic receptors which act to increase HR and force of contraction
- this causes vasoconstriction to increase TPR and BP increases


PNS impact on BP

parasympathetic nervous system (PNS) decreases BP
- Ach released from vagus nerve of PNS binds with cholinergic receptors
- this causes vasodilation and BP decreases


risk factors for hypertension

age - stiffening and changes in CNS increase resistance
ethnicity - african americans have greater resistance and less flow
obesity - more flow because of expanded plasma volume and increased SNS activity


PA and hypertension risk

epidemiological and clinical experiments both provide evidence that moderate intensity PA is assoc with prevention and treatment of MILD hypertension
- it doesn't work well for severe hypertension (greater than stage 1)
- heavy activity doesn't have huge reductions in risk


PA and treatment of hypertension

- works for mild, not for severe hypertension
- seems to benefit women more than men (greater BP drop)
- doesn't work as well for overweight individuals (systolic drops less) BUT drops are independent of weight change++
- most benefit is from moderate PA, not much more for high
- diastolic changes seen most in longer durations of PA


Mill's Canons for hypertension

- temporal sequence: yes. also can do experimental studies to show this
- strength of association: risk reduction 30-50% active
- consistency of results: most studies show reduced risk w PA and this is across diff pop.s also
- does response: unclear bc less seems to be more
- biological plausibility: yes, PA can reduce BP by decreasing Q and/or TPR



having high blood cholesterol/TG levels


4 types of lipids

fatty acids



a modified steroid, made in the liver
- used to make steroid hormones (testosterone, estrogen)
- involved in keeping cell membrane fluid, skin waterproofing



how we store energy in the body
- a glycerol and 3 FAs
- an efficient storage method



make up cell membranes
- hydrophilic head (phosphate/diglyceride)
- hydrophobic tail (2 FA chains)


fatty acids

long hydrocarbon chains with carboxyl groups on the ends
- how we store large amounts of energy



transport fats through blood since they aren’t dissolvable in fluid


classes of lipoproteins

least dense to most dense, also largest to smallest:



least dense lipoprotein, largest in size
- carries fats from food in SI to liver to be processed via the blood



second least dense, second largest in size
- carry from liver to cells of body



second most dense, second smallest in size
- carry primarily cholesterol to body tissues
- most dangerous bc gets oxidized and can lead to atherosclerosis in our blood vessels



most dense, smallest in
- carry cholesterol from body tissues and drops off at liver


endogenous fats

made in the body, not found in our food



a fatty substance found in the body and our food
- manufactured by body from excess alcohol, sugar and fats
- FA chains vary dramatically in length, chains can be saturated or unsaturated (good bc keeps from packing too tightly): the fats we consume have an impact on the type of FA in TG


main TG sources



intramuscular TG

- TG interspersed in muscle fibers
- when mobilized from adipose tissue during exercise are hydrolyzed into FFAs and glycerol which body can use for energy
- transported in plasma by albumin to where needed


total blood cholesterol and heart disease

- greater levels of overall cholesterol increase risk for CHD
- higher or equal levels of HDL to LDL cholesterol reduces your risk of CHD
---- its most important to know how much good to how much bad you have; having more LDL increases your risk the most


amount of HDL cholesterol needed to reduce risk of CHD

in men: 40-50 mg/dl
in women: 50-60 mg/dl


Apo B

a protein present on the outside of cell membranes in lipoprotein molecules caring cholesterol
- is a better indicator of CHD risk than LDL cholesterol levels are


cholesterol levels, CHD risk and treatment of cholesterol

only treat high levels of LDL-C when risk for CHD is also high, otherwise, cholesterol isn't as big of a problem as we thought it might be


risk factors for high hyperlipidemia

- sex (postmenopausal women)
- age (HDL decreases w age)
- % body fat causes HDL to be lower and LDL greater
- diet, alcohol overuse, diabetes all bad for HDL, increase LDL and TG
- smoking and steroids decrease HDL
- exercise increases HDL :)


prevalence of high blood cholesterol in Canada

40% of Canadians have it


Mediterranean diet and cardiac events

people who eat lots of fish, fruits and veg, olive oils, nuts, seeds, minimal red meat: have a LOT less cardiac events than those consuming the traditional Western diet


dietary recommendations by canadian cardiovascular society

- keep fat intake to less than 30%
- less than 200mg cholesterol
- v. little saturated fat
- limit alcohol intake to 1-2 drinks/day


PA and training on hyperlipidemia

- most improvement with aerobic exercise (decreases TG)
- resistance exercise equivocal
- dose response equivocal
- also range in amount of aerobic exercise

-- exercise needs to be coupled with either diet changes or medication if looking to reduce hypercholesterolemia