Lec 1: Intro to CV Diseases Flashcards
Visual of HEART to understand - SLIDE 2
* look at ^ ***
Circulatory System Heart (\_\_\_\_) - - - - \:
Vascular System -> - - -> - -> - -
(pump)
- Regulates blood flow to tissues
- helps maintains body temp
- distributes oxygen/nutrients/hormones throughout the body
- Cardiac cycle:
SYSTOLIC = contraction (phase = emptying)
DIASTOLIC = relaxation (phase = filling)
-> Coronary
- coronary arteries branch off aorta, well oxygenated
- heart receives most of the blood in diastole
-> Cerebral - brain
- blood supply to brain about 15% of circulation
-> Splanchnic - supporting abdominal organs
- Portal vein - gut, liver, spleen, pancreas [75% of total liver blood flow is through the portal vein]
- particularly important for nutr
VISUAL slide 6
Blood Vessels -> - - -> -
Classification of blood vessels
___ > _____ > ____ > _____ > _____
- > Structure
- intima [in touch with blood], media [strong, muscles], adventitia [ outer - shield}
- vasa vasorum [ needed to feed/support bigger vessels EX aorta]
- > Classification
- Arteries, arterioles, capillaries, venules, veins
- b/c capillaries are only one cell layer thick - they only have an intima
Artery (oxygenated blood) > Arteriole > Capillaries > Venule (deoxygenated blood) > Vein
Arterial Pressure -> = -> - - -> ->
HR increases by SNS
HR decreases by PNS
-> so many factors…
Terminology:
CVD
- > Mean Arterial Pressure (MAP) = cardiac output (CO) x total peripheral resistance (TPR)
- > TPR varies as 1/r4
- where r = radius of blood vessel
- as radius decreases, resistance to flow increases!
- > CO = stroke volume (SV) x heart rate (HR)
eg. CO = 70ml/beat x 72 beats/min = 5040ml/min or 5L / min
-> Total blood volume = varies in adults 5.5-7.5L
… that influence CO -> HR (exercise, temp) / SV (strength of contraction)
CVD = Cardiovascular diseases
Broad term referring to disease of the cardiovascular system
Major Problems -> -> - - -> ->
-> Constriction (temporary tightening) of arterial walls -spasms
-> Blockage
- ARTERIOsclerosis
General term for thickening & hardening of arteries
- ATHEROsclerosis
Disease of tunica intima of lg & med size arteries with plaque build up & clot as final event
-> Leaks
- Aneurysm - weak or think spot in arteries
- valves misshappen or functioning poory
-> Contractile rhythm disrupted - pacemakers
VISUAL slide 14
SLIDE 15-Valves of the Heart * know location*** 1 2 3 4
1 Tricuspid valve
Allows the de-saturated blood to flow from the right atrium into the right ventricle
2 Pulmonary valve
Allows the de saturated blood to flow into the pulmonary artery & then into the lungs
3 Mitral Valve
Allows the oxygenated blood to flow from the left atrium into the left ventricle
4 Aortic Valve
Allows the oxygenated blood to leave the left ventricle & enter the main artery of the body = Aorta
Key areas for occlusion or leakage
1 (
2 (
-
SIX major classifications of problems
1-6
1 Coronary (heart attack or myocardial infarction) 2 Cerebral (stroke or cerebral vascular accident) - internal carotid, vertebral arteries 3 Splanchnic arteries
1 Coronary artery disease 2 Rheumatic Heart Disease 3 Congestive Heart Failure 4 Congenital Heart Defects 5 Cerebrovascular diseases 6 Peripheral vascular diseases
CON'D 1 - - - -
[\_\_\_\_\_\_\_ \_\_\_\_\_\_\_] -> - - ->
[______ ______]
- >
- >
- >
- >
- >
[_________]
1 Coronary Heart Disease
- Mainly narrowing or occlusion of arteries of coronary circulation; spasm of smooth muscle
- most common form of CVD in those >40
- often no symptoms until sudden pain
- other names (coronary artery disease/ Ischemic HD / Coronary occlusion/ atherosclerotic HD/ Coronary thrombosis)
[Myocardial Infarction (MI)]
- > Severe ischemia leads to necrosis - irreversible -> scar tissue of the heart muscle - remove VIA surgery if possible
- most result from atherosclerosis of coronary arteries superimposed with coronary thrombosis
- can damage pacemaker -> Arrhythmias
- collateral circulation develops - alt routes of blood supply
- > Symptoms vary from mild to severe, can be fatal - 15% of 1st attacks, 60-75% of 2nd attacks
[ Angina Pectoris]
- > Pain due to heart disease - usually transient occlusion of artery
- > Pain radiates to neck, jaw, back ab, arms
- > Other symptoms include: shortness of breath, nausea, sweating, light headedness
- > Stable : predictable with exercise
- > Unstable : unpredictable, occurs at rest, high risk of MI
[Arrhythmias]
- > Irregularities of contractile rhythm of heart
- Bradycardia - slow (fatigue, dizziness, fainting etc)
- Tachycardia - fast
- > Often secondary to other problems
- > Ventricular fibrillation
- most serious cardiac rhythm disturbance **
- rapid erratic impulses of the ventricles -> halt blood pumping
- > Heart block - atina & ventricles contracting on separate rhythms
2
3 -> -> - - -> - - -
2 Rheumatic Heart Disease
- > Now RARE in CAN
- > Rheumatic fever causes by infection - can affect many organs, including damage to heart valves
- > Affects up to 1% of children in developing countries
- > Early treatment with antibiotics will prevent heart disease
3 Congestive Heart Failure (CHF)
- > Heart failing as a pump
- > Start with an injury to heart or LV hypertrophy
- compensatory mechanisms to deal with BP & volume load
- heart enlarges & changes shape with decreased contractile units & decreased force of contraction
- > Changes are body’s attempt to adapt to & connect problem
- leads to short-term improvement but long term deterioration
- cannot respond to stimuli - exercise, stress
- develop edema, poor cardiac return
3 Con'd Common initiating problems -> - - -> - - Symptoms of CHF - - - - -
-> Increased blood pressure
- left ventricle - pressure to overcome hypertension
- right ventricle - pulmonary pressure
-> Volume Overload
- valves don’t close properly & blood remains in heart to be pumped -> decreases renal perfusion -> activates renin - angiotensin system -> Na + H20 retention
~ Kidneys do not receive enough blood
- increase venous pressure due to blood stagnating in venous system and Na + H20 retention - parts of body enlarge
- SOB, fatigue, weakness, decrease exercise tolerance
- Poor adaptation to cold temperature
- Edema in legs, GI tract, lungs
- May 1st occur with exercise, then with normal activity, then at meals & eventually with bed rest
- Prevalence increased -more in older adults & more in ppl surviving MIs
CON’d
VISUAL slide 27*** look at lauren
- Pulmonary edema:
- -
- Lower extremity or abdominal edema :
: (left ventricular hypertrophy/failure) - failing to pump out blood
- increase in pressures acting across the microvascular walls due to blood volume overload in the lungs -> fluid forced out of the blood vessels accumulates in the lung tissues
- Ascites
- Swelling of ankles & feet
: (right ventricular hypertrophy/failure) - blood from body can’t reach heart due to resistance & therefore stagnates in body
- increase in the pressures acting across the microvascular walls due to blood volume overload in the (lower) body veins -> fluid forced out of the blood vessels accumulates in the extremities or ab area
4 - - - -
-
Ischemic VS Hemorrhagic
-
4 Congenial Heart Defects
- Complex interaction of genetic & environmental factors
eg.German measles, down syndrom e
- Often problems with valves, holes(btw ventricles) & heart muscle function
- young children may develop CHF
- May have:
growth failure, poor food intake, high metabolic rate, respiratory infections
5 Cerebrovascular Diseases
- TIA (Transient ischemic attacks)
- blood supply to brain temporarily inadequate
- symptoms vary depending on area affected
- Stroke - ischemic or hemorrhagic
ISCHEMIC: caused by a restriction in blood supply to tissues, leading to a stortage of oxygen & glucose needed for cellular metabolism
HEMORRHAGIC: caused by rupturing of a weakended blood vessel
6 Peripheral Vascular Diseases
- Atherosclerosis in peripheral arteries
- Intermittent claudication
- typical patients is 50y old male with hypertension, smoker
- legs comfortable at reat, pain & weakeness on walking (accumulation of metabolic intermediate products such as lactate & increase reactive oxygen species -> further injury)
- absent ankle/foot pulse
- if occluded, must be amputated
Epidemiology of CVD GRAPH slide 33-37 FYI - High groups - increase with age (structure of vascular system changes) - 1 of highest cost diseases - on decline but still prevalent - men larger risk GRAPH - slide 38 Older age
“is a growing epidemic”
Decline in CVD mortality -> Multiple reasons - - - - -
- 25% primary prevention
- decrease in smoking
- diet changes - decrease in sat fat, increased PUFA
- 29% treatment of HTN, high cholesterol, type 2 DM
- 43% better management of clinical CVD
Etiolgy & Pathophysiology of Atherosclerosis ETIOLOGY - natural history - - - - -
SLIDE 43 - ***** to understand - oxidized LDL
+ SLIDE 44-47 ** plaque rupture w clot formation is big problem
- Ischemic heart disease epidemic of 20th century
- atherosclerosis was rare befroe 1900 in pathology reports; started to increase since then
- > 2 major processes
- development of atherosclerosis
- clotting abnormalities
- > Lots of risk factors (>200) inconsistent evidence
- prediction equations include some of these risks
Risk Factors
~4
Modifiable Risk Factors
~ 7
1 Age
2 Gender - at younger ages, men @ higher risk - 10 yr lag for women
3 Family History
- familial IHD MEN <55yr, Women <65 yr (1st degree relatives)
- dyslipidemias
- type 2 diabetes
4 Ethnicity
[ Differences in the pathophys of CVD - including interference of sex hormones
- Differences in the prevalence of risk factors
1 Smoking - major
2 Hypertension - result of & increased atherosclerosis
3 Diabetes - increased risk for HT
4 Dyslipidemia - important risk factor
5 Role of Obesity? - independent risk factor as well
- overweight & obesity can affect the heart structure & function
- **obesity may affect the heart through its influence on known risk factors such as dyslipidemia, hypertension, glucose intolerance, inflammatory markers, obstructive sleep apnea/ hypoventilation, the prothrombotic state & others
6 Physical inactivity
- independent effect?
- difficult to study due to measurement error
7 Diet
- fat, salt - more recently sugar
- independent risk factors or act through other factors?
- fat intake has declined from 38% to 31% (sat fat decreased, MUFA/PUFA increased)
- increased salt and sugar
Other factors? - - - -
Predication Equations - - - -
Framingham risk scores (FRS)
- slide 53/54
- get score then next steps are defined * know risk factors on scale:
- Stress, work control, SES
- Lipoprotein A -> like LDL - but a subtype ONE of the most atherogenic lipoproteins
- Fibrinogen levels - responsible for blood clot formation; higher with abdominal obesity?
- C-reactive protein
- marker of inflammation
- higher levels associated w risk (chronic inflammation) - surgery/treatment
- levels often elevated in smokers
- 1st generated from the Framingham Study (since 1948)
- most successful observational cohort study on CV medicine (over 5000ppl)
- advance in looking at risk factors for CVD @ time
- helps motivate patients to attend to risk factors - BUT up to 1/3 of MI occur in patients w/o major risk factors
: age/ HDL-C/ Total Cholesterol / systolic BP (is it treated?)/ smoker/ diabetes
