APP Module (GTown) - Cardiovascular Pathophysiology II (Hrs 3 and 4) Flashcards
What is the defining feature of disseminated intravascular coagulation?
its consumptive coagulopathy
Give a general outline of the steps in the progression of endothelial injury
1) endothelium ceases making normal antithrombic/vasodilatory substances
2) immune inflammatory response
3) oxidation and phagocytosis
4) fatty streak accumulates and smooth muscle proliferates
What are three clinical consequences of atherosclerosis?
1) aneurysm and rupture
2) occlusion by thrombosis
3) critical stenosis
What is the relationship of genetic factors, acquired factors, and age?
Genetic factors play a large role at an early age, but this transitions to acquired factors playing more of a role as time goes on
What are the four steps in thrombosis?
1) propagation thru platelet accumulation/fibrin
2) embolization
3) dissolution
4) organization and recanalization
Where do arterial thrombi usually begin?
at a site of turbulence or endothelial injury
In what direction do arterial thrombi grow?
retrograde, against the flow
What is a mural thrombus?
a thrombus that accumulates on the wall of the heart
What is a cause of a mural thrombus?
myocardial infarction which causes injury to the wall of the heart and thus stagnation of blood
What is a clinical consequence of rheumatic heart disease?
mitral valve stenosis
Mitral valve stenosis leads to left atrial enlargement which leads to the risk of what?
LAE predisposes to AFib which increases the risk of a thromboembolic event, especially a stroke
What are venous thrombi caused by?
usually stasis of blood flow and hypercoagulability
Which direction do venous thrombi grow?
anterograde, in the direction of flow
Why might venous stasis cause endothelial injury?
stasis of blood leads to accumulation of toxins and waste byproducts leading to a damaged endothelium
What are the two types of venous thrombi?
1) local or superficial venous thrombi
2) deep vein thrombi
What is an embolism?
a detached intravascular mass, whether solid, liquid, or gas, e.g. fibrin clot, fat, or air
What is a primary cause of the thrombus in a pulmonary embolism?
deep veins of the leg
What percentage of the pulmonary circulation must be occluded to cause sudden death?
> 60%
What is the worst type of PE?
saddle embolus
Where is a saddle embolus located?
Bifurcation of the pulmonary trunk
What are some examples of systemic thromboemboli?
intracardiac or mural thrombi, ulcerated atherosclerotic plaques
What is the first step in atherosclerosis?
intimal thickening
What is atherosclerosis defined as?
a hyperinflammatory state
What are the factors in plaque formation?
1) endothelial dysfunction
2) monocyte adhesion and emigration
3) smooth muscle cell migration to intima
4) smooth muscle cell proliferation
5) ECM elaboration
6) lipid accumulation
What is an atheroma?
an accumulation of degenerative material, usually foam cells, LDL, lipids, and fibrous tissue in the inner layer of an artery wall.
What is the difference between a vulnerable plaque and a stable plaque?
A stable plaque has a stable fibrous cap and more overlying fibrotic tissue whereas a vulnerable plaque will have a larger necrotic center and less extensive fibrous cap vulnerable to rupture
What are the two factors that are imbalanced in the initiation of myocardial ischemia?
1) coronary artery blood supply
2) myocardial oxygen demand
What are some factors that affect coronary artery blood supply?
1) presence of coronary plaques
2) perfusion pressure
3) arterial blood oxygen content
What are some factors that affect myocardial oxygen demand?
1) preload
2) heart rate
3) afterload
4) contractility
What are the two factors in the regulation of blood pressure?
1) cardiac output
2) peripheral vascular resistance
What two factors affect cardiac output?
cardiac factors
blood volume
What are the three factors which mediate peripheral resistance?
1) local factors
2) humoral factors
3) neural factors
What are the two major influences of hypertension?
1) genetic factors
2) environmental factors
What three genetic and environmental influences lead to an individual with hypertension?
1) defects in renal sodium homeostasis
2) functional vasoconstriction
3) defects in vascular smooth muscle growth and structure
What is an aneurysm?
abnormal dilation of a blood vessel
What is a true aneurysm and what are the two types?
A true aneurysm is actual dilation of the entire vessel wall. The two types of true aneurysm are the 1) saccular aneurysm, and the 2) fusiform aneurysm.
What is a false aneurysm?
A false aneurysm is a tear in the inner layer of a blood vessel causing an extravasation into the outer layers and thus dilation into the adventitia
What is a dissection?
A tearing of the vessel wall so that blood enters the space between the intima and media
What are the most common cause of abdominal aortic aneurysms?
atherosclerosis
What are the most common cause of thoracic aortic aneurysms?
hypertension
What is forward (heart) failure?
When the left ventricle cannot pump enough blood to meet the demands of the body
What is backward (heart) failure?
When failure of the heart causes venous back-up
What are three causes of forward failure?
1) systemic hypertension
2) mitral or aortic valve disease
3) ischemic heart disease
What is it termed when the adaptive mechanisms we employ are enough to make up for a decrease in heart function?
compensated heart failure
What remodeling of the ventricular wall occurs in heart failure?
dilatation
What is concentric hypertrophy?
equal or concentric hypertrophic growth of the whole ventricle
What is concentric hypertrophy caused by?
chronic pressure overload
What is eccentric hypertrophy?
unequal, or eccentric, hypertrophic growth that increases the lumen or chamber size preferentially
What is eccentric hypertrophy caused by?
chronic volume overload
What happens when are adaptive mechanisms fail to make up for heart dysfunction?
decompensated heart failure
What are some signs/symptoms of decompensated heart failure?
- orthopnea
- dyspnea
- pulmonary congestion
- cyanosis
- acidosis
What is the cause of ischemic heart disease (IHD)?
Imbalance in myocardial oxygen demand and supply
What is another term for ischemic heart disease?
coronary heart disease or coronary artery disease
What is a common cause of IHD?
coronary artery lumen narrowing
What are the four presentations of IHD?
1) angina pectoris
2) acute MI
3) sudden cardiac death
4) chronic ischemic heart disease leading to CHF (ischemic cardiomyopathy)
What is angina pectoris?
substernal and intermittent chest pain caused by a (>70%) blockage of the coronary artery causing transient and reversible myocardial ischemia
What are the three types of angina pectoris?
1) stable
2) variant
3) unstable
What is stable angina?
Chest pain relieved with rest or decreased demand
What is variant angina?
Chest pain even at rest but that occurs in cycles due to vasospasm
What is unstable angina?
Chest pain that is worsening or not relieved by decreased demand, rest, or vasodilators
What is another term for unstable angina?
acute coronary syndrome
What is the difference between unstable angina and an acute MI?
You do not see appreciable myocardial damage in unstable angina and thus troponins are negative or not significantly elevated
What is the first region to be affected in an MI?
endocardium, that section of the heart which is furthest from the blood vessels
What does the cell death from an MI cause to leak into the blood stream?
1) LDH
2) CK-MB
3) troponin T and I
What two cardiac enzymes are used to determine an acute MI and which one is more specific?
1) CK-MB (creatine kinase)
2) troponin (more specific)
What is the timeline of CK-MB levels after a myocardial event?
1) presence in blood detected 2-4 hours after
2) peaks at 18 hours
3) normal by 48 hours
What is the timeline of troponin levels after a myocardial event?
1) presence in blood detected 3-6 hours after
2) peaks at 16-30 hours
3) normal by 4-7 days, but may remain elevated for up to two weeks
What is an MI?
area of ischemic necrosis due to occlusion of arterial supply or venous drainage from thrombus or sepsis
What are the four factors which determine the nature of an infarction?
1) nature of the vascular supply
2) rate of development of occlusion
3) tissue vulnerability to hypoxia
4) oxygen content of blood
What are four treatments for MI?
1) thrombolysis (tPA)
2) stent placement (drug-eluting or metal)
3) PTCA (percutaneous transluminal coronary angioplasty) or PCI (percutaneous coronary intervention)
4) CABG
What is cardiomyopathy?
“heart muscle disease”
What are the three types of cardiomyopathy?
1) dilated
2) restrictive
3) hypertrophic
What is dilated cardiomyopathy?
progressive form of cardiac hypertrophy associated with dilation and cardiac systolic dysfunction
What is hypertrophic cardiomyopathy?
asymmetric septal hypertrophy or idiopathic hypertrophy leading to impaired diastolic filling and dynamic outflow obstruction
What is a primary cause of HCM?
genetics and myocardum mutations (dystrophin)
What is the difference in the hearts of those with dilated vs. hypertrophic cardiomyopathy?
Dilated cardiomyopathy leads to a “baggy” heart that is hypocontracting. Hypertrophic cardiomyopathy leads to a thick hypercontracting heart
What is restrictive cardiomyopathy?
Decrease in ventricular compliance which affects preload and a stiff and inelastic ventricle
What are two common causes of restrictive cardiomyopathy?
1) endomyocardial fibrosis
2) cardiac amyloidosis
What is cor pulmonale?
Heart disease caused by lung disease
What does cor pulmunolae lead to?
pulmonary hypertension, right ventricular hypertrophy or dilation, and right heart failure
What is the characteristic triad of aortic stenosis?
1) angina, not explained by IHD
2) dyspnea on exertion
3) syncope
What is the most common cause of aortic stenosis?
Calcific valvular degeneration from normal wear and tear and old age (>50%)
At what point does aortic stenosis become “hemodynamically significant”?
1) mean transvalvular gradient above 50 mm Hg
2) valvular surface area under 1 square cm
What are the next most common causes of aortic stenosis after calcific valvular degeneration?
bicuspid aortic valve (30-40%)
rheumatic heart disease (10%)
What causes almost all mitral valve stenosis?
post-inflammatory scarring causing fusion of mitral leaflets after rheumatic heart disease
At what point does mitral stenosis become “hemodynamically significant”?
mitral valve area is less than 1 square cm
left atrial pressure rises to above 25 mm Hg
What is the end outcome of severe mitral stenosis?
congestive heart failure
What is rheumatic heart disease?
Group A strep infections cause a cross-reaction during the immune response which attacks the mitral valve. Healing after this infection causes valvular damage
What does mitral stenosis also predispose you for?
atrial fibrillation
What is another name for valvular regurgitation?
valvular incompetence or insufficiency
What is the most common form of valvular heart disease?
mitral insufficiency (regurgitation)
In what condition do you heart an Austin-Flint murmur?
aortic insufficiency
What type of hypertrophy does aortic stenosis lead to?
concentric hypertrophy
What is mitral valve prolapse?
the ballooning of the leaflets of the mitral valve in systole due to a lack of structural integrity
The weakening of the connective tissue that occurs in MVP is termed?
myxomatous degeneration
What are some acute causes of aortic regurgitation?
1) trauma
2) infective endocarditis
3) thoracic aneurysm dissection
What are some chronic causes of aortic regurgitation?
1) prior rheumatic fever
2) persistent systemic hypertension
What hemodynamic effect is characterized by aortic regurgitation?
Hyperdynamic pulses = ↑ pulse pressures
