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Cardiovascular Disease Physiology Exam
Cardiovascular Disease, Physiology Exam 3
What are the uncontrollable risk factors of CVD?
heredity and race
What are the controllable risk factors?
overweight and obesity
diabetes (type II)
What is atherogenic?
means that it irritates vascular endothelial cells and increases platelet adhesion
an inflammatory response to damage of vascular endothelium
How does smoking affect CVD?
increases blood pressure
increases LDL (bad) cholesterol and decreases HDL (good) cholesterol
What are the several types of CVD?
1. ischemic heart disease
4. heart failure
What is ischemic heart disease?
definition: oxygen consumption of heart exceeds supply
What is the most common type of heart disease?
Ischemic heart disease
6.8% of Americans (1 in 14, about 18.5 million ppl)
What is the most probable cause of ischemic heart disease?
atherosclerosis in coronary arteries (CAD)
How is plaque form?
expansion of the intimal layer of an artery
consist of a fibrous cap that overlays a lipid core (intensely thrombogenic)
form at branches and curves in arteries = areas with increase hemodynamic forces on walls = sheart stresses - turbulent instead of laminar blood flow
How is plaque ok?
usually not the cause of acute problems
stable plaques can be stenotic - narrowing the arteries - tend to be benign
How are plaques bad?
plaque can rupture
lipid core escaptes -> clot formation
sudden and dramatic occlusion of artery = myocardial infarction or ischmemic stroke (80% of strokes)
What is angina pectoris? What are the symptoms?
strangling in the chest
episodes of chest pain/tightness/heaviness (poorly localized, difficult to describe)
What caused angina pectoris?
transient decrease in blood flow (so cardiac demand transiently exceeds supply)
What provokes demand angina?
Provoked by increase physical work (exercise/exertion) and stress (cold, emotion) relieved within minutes by rest
What provokes supply angina?
provoked by sudden decrease in supply
ex. occlusion from clot
Describe stable angina.
short term prognosis fairly good
2-3% death per year if truly stable
if underlying CAD is managed
Describe unstable angina.
intermediate between stable agina and infarction
usually corresponds to worsening of stable angina (severity or duration of events increased, or exertion to trigger events decreased)
caused by dynamic plaque
considered a medial emergency, prognosis
highly increase risk of myocardial infarction, esp in first 6-8 weeks
acute mortality (24 h) - about 4%
What is myocardial infarction?
death of myocardial tissue caused by lack of blood supply
Where does myocardial infarction happen most often?
in left ventricle
In myocardial infarction, the myocardial cell death begins within 15-40 minutes after what?
After occlusion of artery, very few ceels left after 6 hours
after mycocardial infarction, cells are replaced with what?
with collagen scar = no contraction -> weakens heart
What are the symptoms of myocardial infarction?
sever chest pain
shortness of breathe
: sweating, weakness, nausea, vomiting
loss of heart function
more than 30% SILENT (more common in elderyly and diabetics due to poor innervation so less feeling of pain)
How do you diagnosis myocardial infarction?
Diagnosis needs 2 of 3 but markers very reliable
damaged cells leak proteins into blood = markers for infarction
medical history indicates ischemic chest pain >20 mintues
ECG changes (ST segment shifts, abnormal Q waves)
what are the proteins that can leak into blood as markers of myocardial infarction?
troponin T (sepcific for cardiac muscle damage, rises quickly. before permanent damage)
What are the limitations of stress tests for myocardial infarction?
evaluate blood flow during exercise vs. during rest - only detects severe narrowing
cannot detect vulnerable plaques, which cause most infarctions but which are usually <50% occlusion
blood pressure of more than 140/90 compared to normal of 120/80
What is hypertension bad?
"silent killer" - no symptoms
irreversible so drugs can only treat condition
can lead to left ventricular hypertrophy => eventual cause of heart failure
damages vascular endothelium - so causes atherosclerosis
can caus aneurysms (bulges in vessels) =weak, chance of rupture; ruptures in cerebral arteries = hemorrhagic stroke
usually results in arteriosclerosis = hypertrophy in veesls, reduced compliance - normal increase in BP w/ aging
What causes hypertension?
not well understood
kidney and adrenal gland (not heart) are major determinants
what are the controllable risk factors of hypertension?
high salt intake
high alcohol consumption
lack of physical acdtivity (ind. of weight)
What are the uncontrollable risk factors of hypertension?
older than 60
Hypertension is clear cause of death in ______ of patients who suffer from it.
50% die from heart disease or heart failure, 33% stroke, 5% renal failure
Linear relationship between degree of hypertension and risk - after 115/75, each increase of 20/10 ________ risk of cardiovascular disease incidents.
135/80 prehypertension = 2x risk
155/95 hypertension = 4x risk
175/105 stage 1 hypertension = 8x risk
as disorders of cardiac rate and rhythm
can be benign or acutely life-threatening
What are the rate disorders?
bradycardia - too slow
tachycardia - too fast
can be supraventricular or ventricular (usually more severe)
caused by sinus node dysfunction and/or ectopic pacemakers