cardiovascular Flashcards
(199 cards)
1
Q
what is the #2 cause of death in Canada?
A
Atherosclerosis
2
Q
what are the consequences of atherosclerosis?
A
myocardial infarct, stroke, aneurysm, peripheral vascular disease
3
Q
what event initiates atherosclerosis?
A
endothelial injury and dysfunction
4
Q
what is called the build-up in the intima in atherosclerosis?
A
buildup of atheroma
5
Q
do veins have smooth muscle?
A
yes but thinner than arteries because they carry blood at lower pressure
6
Q
do arteries or veins have valves? why?
A
veins: to maintain unidirectional blood flow against gravity
7
Q
describe the 3 layers in the artery wall from inner to outer
A
intima: single layer of endothelial cells (all vessels)
media: smooth muscle
externa: connective tissue
8
Q
describe the 3 layers of veins wall from inner to outer
A
endothelial cells
smooth muscle
external wall
9
Q
what deposit on walls of the aorta?
A
cholesterol (fatty streak)
10
Q
what is atherosclerosis?
A
harmful fibrous tissue accumulation in the intima
11
Q
what are the 2 outcomes of atherosclerosis?
A
plaque rupture or grows until complete occlusion
12
Q
what is an angina?
A
chest pain caused limited blood flow through coronary artery due to atherosclerosis
13
Q
what is stenosis of the lumen?
A
narrowing of the lumen
14
Q
what is a thrombus?
A
blood clot that can form on the plaque and cause vessel to rupture (stays there)
15
Q
what can be caused by vessel occlusion in the periphery?
A
gangrene in extremities
16
Q
what is the other term for angina?
A
transient ischemic attack
17
Q
what causes the pain of angina?
A
inadequate blood flow during physical activity
18
Q
what are the CNS symptoms of angina?
A
difficulty speaking and moving (happen transiently)
19
Q
what is a myocardial infarction?
A
ischemic stroke: vessel occludes completely and causes death of cells in the brain or heart
20
Q
what are the symptoms of peripheral arterial disease?
A
intermittent claudication (on and off blood flow to the legs causing pain during exercise)
21
Q
what are the key components of atherosclerosis pathogenesis?
A
endothelial dysfunctions and chronic inflammation in the arterial intima
22
Q
3 things that cause endothelial injury
A
hyperlipidemia, hypertension, smoking
23
Q
how do vessels respond to injury of endothelial cells? what do these responses do?
A
retract (increase permeability) and release signaling molecules. this initiates atherosclerotic plaque formation
24
Q
where is hemodynamic stress the most notable?
A
at branch points (area more susceptible to injury)
25
what are the 3 big sections of atherosclerosis pathogenesis?
hemodynamic stress, cell mediators/cytokines, lipoprotein accumulation
26
where is hemodynamic stress most notable?
at branch points
27
what induces smooth muscle proliferation after an injury?
mediators (macrophages, platelets, lymphocytes, fibroblasts, SM cells) and the growth factors they release
28
what kind of process is atherosclerosis development?
inflammatory process
29
what are foam cells?
modified macrophages formed after taking up LDL that release inflammatory cytokines/mediators
30
describe the function and structure of lipoproteins
carry lipids in blood.
inside = triglycerides and cholesterol
surface = phospholipids, free cholesterol, apoprotein
31
what type of lipoprotein has the most protein content? what does it do?
high-density lipoprotein HDL: brings lipids back to the liver
32
which lipoproteins are considered bad?
LDL and VLDL. they can deposit cholesterol to blood vessel walls
33
what are chylomicrons?
triglycerides from which we absorb lipids from intestines
34
how are LDLs a risk for atherosclerosis? (2 reasons)
their Apo B protein gets recognized by LDL receptor on cells -> LDL gets internalized and broken down in lysosome -> free cholesterol.
also, they activate inflammatory processes
35
what type of LDLs are most present in atherosclerosis plaques?
modified / oxidized LDLs
36
what are the 2 types of receptors that take up LDLs?
LDLR and scavenger receptors
37
what apoprotein is found on HDL surface?
Apo A
38
smooth muscle cells can form a fibrous cap on antheroplaque that has what function?
helps reduce risk of plaque rupture
39
how else do smooth muscle cells contribute to atherosclerosis?
accumulate lipids, synthesize collagen, elastin, glycoprotein, synthesize ECM -> enlarges the plaque / forms fibrous cap
40
what is an embolus?
something that moves through blood vessels and eventually blocks one that is too small to let it pass
41
name the cells involved in formation of a plaque
stem cells from bone marrow, foam cells
42
risk factors for atherosclerosis
hyperlipidemia, hypertension, smoking, toxins, obesity, metabolic syndrone, type 2 diabetes
43
what is caused by T2DM (type 2 diabetes mellitus)
high LDL, high triglycerides, high BP, low HDL
44
complications of atherosclerosis
ischemia (complete occlusion), renal ischemia, intermittent claudication, thrombus, embolus, plaque rupture (causes blood clot)
45
what is an aneurysm
weakening of vessel wall causes the vessel to bulge out because the artery is under pressure
46
how do cigarettes increase risk of atherosclerosis?
activates platelet aggregation, increased CO, impaired oxygen delivery, interferes with HDL production, hypertension,
47
what is familial hypercholesterolemia?
rare genetic defect in LDL receptors causing too much LDL in circulation, dengerous for atherosclerosis
48
what is PCSK9?
loss of function mutation that causes degradation of LDL receptors
49
what is the difference between saturated and unsaturated fat?
saturated = bad! lacks double bonds. decreases LDL receptors
unsaturated = good. protect you
50
which oil is the best?
canola; low saturated fat, high unsaturated
51
what is type 1 diabetes?
islets of langherhans are not making enough insulin
52
what is type 2 diabetes?
insulin resistance due to lifestyle (obesity)
53
what are metabolic syndrome symptoms?
abdominal obesity, hyperinsulinemia, high glucose levels, hypertriglyceridemia, low HDL, high HDL, hypertension
54
what does the activation of insulin receptors cause?
uptake of glucose, free fatty acids, and amino acids
55
how does diabetes affect LDL levels?
increases LDL in circulation
56
what % of people with T2DM die of coronary heart disease?
80%
57
how can insulin resistance affect endothelium?
glucose derivatives damage endothelium and ECM and can generate free radicals.
also increases vessel permeability.
can cause edema, ischemia, neovascularization
58
how are plasma C reactive proteins (CRP) related to coronary vascular disease?
higher CRP levels = more inflammation = diabetes
59
what is thrombosis?
formation of blood cloth in the vasculature
60
how is thrombosis developped from atherosclerosis?
platelets aggregate, adhere, and degranulate -> thrombosis
61
what is PGI2?
prostacyclin, an antithrombotic released by healthy endothelium
62
what does prostacyclin do?
promotes vasodilation and blocks platelet aggregation
63
3 contributors to thrombosis
endothelial injury -> abnormal blood flow and hypercoagulability
64
what can cause hypercoagulability?
changes in blood composition after childbirth or surgery (increased platelets, prothrombin, and fibrinogen)
65
what causes thrombosis in different vessels?
arteries: endothelial injury and plaque rupture
veins: slow blood flow, hypercoagulability & injury
66
what is deep vein thrombosis
DVT: stasis of blood flow in legs after sitting for long. possibility of thrombus forming
67
what can cause a thrombus in the heart?
infarct (damage to heart surface promotes platelets)
68
3 common sites of thrombus formation
heart, brain, periphery
69
what is the classical case of embolism
embolus form around the valves in deep vein in the legs, goes to heart then lungs -> pulmonary embolus
70
what can help in a small pulmonary embolus?
collateral circulation from bronchial artery
71
where will an embolus cause instant death?
if it's stuck at the bifurcation to the heart
72
what happens if there is no collateral circulation?
infarct
73
what is blood flow proportional to?
the 4th power of the diameter of a vessel
74
what are the 2 main forces acting on artery?
BP and resistance to distension
75
where can micro-aneurysms be seen?
brain and retina
76
describe the 2 types of aneurysms
fusiform: bulges all around
saccular: localized on one side
77
where is berry aneurism?
in circle of Willis
78
what is cardiac tamponade?
tear in aortic wall and blood accumulates in pericardial sac; heart can't pump properly
79
what causes varicose veins?
increased pressure in feet when standing up causes valves to not close properly
80
what proportion of blood is always in our venous system?
2/3
81
pathogenesis of varicose veins (4 things)
prolonged standing, pregnancy, obesity, cellulitis
82
what is the biggest risk factor for heart diseases?
hypertension
83
what is the best value for blood pressure?
120/80 mmHg
84
what is the cut-off BP value for risks of coronary heart disease?
140/90
85
what happens with each 20/10 mmHg increase in BP?
cardiovascular mortality risk doubles
86
how do high temperatures affect BP? why?
blood vessels vasodilate so BP decreases
87
should BP increase with age? why does it do so in Canada and US?
no.
because we eat too salty
88
what are the factors involved in essential/idiopathic hypertension?
salt, lack of exercise, obesity, drinking, smoking, stress, inadequate electrolytes, family history
89
examples of how BP is controlled by body
arteries contract/relax,
autonomic nervous system,
endocrine system,
kidneys (renin-angiotensin system),
diet
90
what is the "formula" of BP?
cardiac output x peripheral resistance
91
how does salt affect BP?
more salt -> more water retention -> higher blood volume -> higher CO -> higher BP
92
hypertension complication related to the heart?
cardiac hypertrophy
93
which ventricle gets enlarged? why?
left. it enlarged to accommodate the increased blood volume and pressure
94
hypertension complication related to arteries?
hypertrophy and hyperplasia of smooth muscle cells,
fibroblast proliferation into myofibroblasts, leukocytes recruitment,
arteriolosclerosis in small eye, kidney, adrenal vessels,
vascular damage
95
3 random complications of hypertension on arteries?
renal failure, impaired vision, necrosis with fibrosis
96
how can hypertension cause atherosclerosis?
causes vessels to narrow and have a thickened wall which increases pressure on branch points.
vicious cycle of one leads to the other
97
what neurological disease can be caused by hypertension?
Alzheimer's disease
98
how does hypertension affect blood brain barrier?
increases permeability (bad because more things can enter and injure the brain)
99
what is Charcot-Bouchard aneurysm?
weakening of the wall of vessel in the brain can lead to vessel repture
100
what is fibroid necrosis?
formation of fibroid due to sever hypertension
101
what is a transient ischemic attack?
TIA is a stroke that lasts a few minutes
102
symptoms of hypertension syndrome
obesity, abnormal lipid and carbohydrate metabolism, diabetes, renal failure, blood clotting
103
how does high salt intake affect vascular smooth muscle? how does it affect BP?
increase calcium uptake through Na+/K+ and Ca2+ exchange, which increases constriction and increases BP
104
how does high salt diet affect the brain?
increases sodium in CSF which increases sympathetic activity & vasoconstriction
105
lowering BP by as low as _____ mmHG can have lots of benefits
15 mmHg
106
what compound can you increase in diet to help bring BP down? which one should you decrease?
increase potassium
decrease sodium and saturated fat
107
what is ischemic heart disease?
impaired blood flow to the heart
108
3 major vessels supplying the heart?
left anterior descending (most commonly blocked), right coronary artery, left circumflex
109
coronary heart disease
Atherosclerotic plaque in arteries of the heart proximal to the main coronary arteries
110
what is stenosis
narrowing of the lumen of a vessels
111
at what % of blocked arteries do you start to see symptoms?
70% blocked
112
what is angina pectoris and when does it happen
chest pain due to impaired blood flow to the heart
113
what determines the preload to the heart?
venous return
114
what is the afterload?
blood pressure; greater pressure = greater afterload = greater pumping
115
characteristics of cardiac myocytes related to energy
high energy requirement (fuel Na/K pumps & need lots ATP)
low energy reserve (no big glucose store)
116
where can angina pain be felt? why?
chest, neck, shoulder, left arm, jaw.
due to convergence in afferent pathway on spinal column
117
what other than atherosclerosis can cause angina?
coronary artery spasm
118
how are coronary artery diseases detected?
ECG treadmill stress test
119
how can angina be treated? in what cases does this treatment not work?
vasodilator nitroglycerin. can't relax smooth muscle if there is a circumferential atherosclerotic plaque
120
what surgery for angina?
coronary artery bypass surgery with left internal mammary artery (if LAD is blocked)
121
describe the other procedure (not a major surgery) to solve angina
coronary angioplasty: balloon inflated in the vessel to break the atherosclerotic plaque. now, we can also place a stent that can release vasodilators
122
what is myocardial infarct
total occlusion of the blood flow to a portion of the heart
123
4 causes of occlusion in myocardial infarct
thrombus, embolus, hemorrhage, spasm
124
what is a variant angina?
angina caused by coronary artery spasm. can't cause an infarct
125
what % of myocardial infarct lead to svdden death
20%
126
where will you feel pain during myocardial infarct
left side of the chest, arm, and face
127
whats the most important variable in an infarct?
collateral circulation
128
2 different types of heart failure (consequences of infarct)
mechanical failure (section can't beat)
electrical failure (arrhythmias)
129
what do you see on ECG for coronary artery ischemia, injury, and infarct?
ischemia: t wave inversion
injury: S-T segment elevation
infarction: Q wave inversion
130
how does the blood change after myocardial infarct?
myocytes enzymes and higher neutrophil count. (can be used to measure severity of injury)
131
3 markers of acute myocardial infarct
myoglobin
troponin
CK-MB
132
what is ventricular fibrillation? how to treat it?
uncoordinated electrical activity of the ventricles.
treatment = defibrillatory shock
133
what drugs can help in the 4 hours after arrhythmia attack?
thrombolytic drugs
134
how will they treat you in coronary care unit?
electroshock, antiarrhythmic drugs, thrombolytic drugs, oxygen, morphine, nitroglycerine, B-blockers
135
complications of MI
- thin ventricle wall
- thrombus
- cardiac rupture (Death)
- papillary muscle rupture
- ventricular septal defect
- ventricular aneurysm
136
what are C-reactive proteins
proteins whose levels are elevated in inflammatory diseases. increase risk of cardiovascular death
137
can heart disease be reversed?
yeah
138
what are medication against heart diseases?
timolol: beta-blocker that keeps BP down
aspirin: reduces clumping of platelets
139
describe the trajectory of an electrical wave in the heart
SA node -> through the atria -> AV node -> bundle of His -> right/left bundle branch -> purkinje fibers -> cardiomyocytes
140
what is the main pacemaker of the heart?
SA node.
AV node is the back up pacemaker
141
what are the rates of the SA node, AV node, and ventricular system?
SA node = 60-100 bpm
AV node and HIs-purkinje system = 40-60 bpm
Ventricular system = 20-45 bpm
142
what are called the specialized connections between myocytes? what is their role?
intercalated disks: allows rapid spreading of the action potential and provide better coordination
143
what causes the initial rise in membrane potential that triggers the AP?
Na+ inflow through fast V-gated channels opening
144
what happens after the initial Na+ influx?
depolarization plateau maintained by Ca++ influx, then K+ outflow allows repolarization
145
what are the effect of the sympathetic stimulation on the heart
increases contractility, frequency, conduction velocity, irritability
146
what neurotransmitter transfers sympathetic stimulation?
noradrenaline and adrenaline
147
what neurons work to slow the pacemaker down?
vagal motor neurons
148
explain the ECG waves
P wave = atrial depolarization
QRS complex = ventricular depolarization
T wave = ventricular repolarization
149
what is the type of arrhythmia that slows vs increases heart rate?
bradycardia = slow heart rate
tachycardia = rapid heart rate
150
what is sinus bradycardia?
impulses originating from SA node at a slow rate
151
what is respiratory sinus arrhythmia?
faster heartbeat when breathing in, slow when breathing out (harmless)
152
atrial arrhythmia pathogenesis: what is heart block
AV node block. only P wave is seen on ECG
153
atrial arrhythmia pathogenesis: what is ectopic focus?
atrial fibrillation: no coordinated contractions due to random electrical activity in the heart. dangerous but doesn't necessarily kill
154
atrial arrhythmia pathogenesis: what is circus re-entry?
damaged purkinje branch causes signal to travel in opposit direction
155
what are the consequences of atrial arrhythmia?
- sinus (SA node) arrest
- flutter (rate 200-400 bpm
- fibrillation: unsynchronized contractions
156
what do pacemakers do?
kick in when SA node stops functioning
157
why is ventricular function critical in atrial arrhythmias?
If the ventricles are functioning normally, the person will most likely stay alive
158
what does it do that the inside of the heart is a thrombogenic surface?
increasing risk of thrombus that can lead to stroke if blocking vessel to brain
159
what are the 2 biggest risk factors for a stroke?
atrial fibrillation and hypertension
160
what are consequences of ventricular fibrillation?
death within minutes
161
when can a defibrillator be used?
during ventricular defibrillation
162
what is systole vs diastole?
systole = ventricles contract
diastole = ventricles relax, atria contract
163
what is stenosis? what can it cause?
narrowing of the opening of a valve. can cause regurgitation (blood flows backward)
164
what is incompetence?
valve can't close properly
165
what causes rheumatic heart disease?
ear or throat infection with B-hemolytic streptococcus (similar antigen on heart valves)
166
what is the major cause of heart valve damage?
rheumatic heart disease. can become chronis
167
what are causes of valve diseases?
rheumatic heart disease, IV drug use, immunocompromission, sepsis, streptococcy, staphylococcy, fungi
168
what is aortic stenosis? what are the symptoms?
calcification of the aortic valves.
symptoms = angina, syncope
169
what is syncope?
fainting due to inadequate blood flow to coronary arteries
170
how does the heart adapt to aortic stenosis?
left ventricle hypertrophy
171
what is aortic regurgitation and the symptoms?
aortic valve can't close properly, blood flows back into left ventricle.
symptoms = fatigue, dyspnea
172
how does the heart adapt to aortic regurgitation?
left ventricle dilation leading to heart failure eventually
173
what are the symptoms of mitral stenosis? how does the heart adapt?
fatigue and dyspnea.
left atrium hypertrophies and dilates. right ventricle hypertrophies
174
what is mitral regurgitation symptoms and adaptations?
dyspnea.
left and right ventricles dilate and hypertrophy
175
how can heart valve disease be treated?
surgery to repair to valve
176
What is the final outcome of arrhythmias and valvular heart disease?
congestive heart failure
177
describe congestive heart failure
Inadequate cardiac output leads to tissue that become congested because of edema and fluid flowing out of the vasculature
178
what are the symptoms of congestive heart failure?
swollen ankles, kidneys retaining fluid, enlarged heart, congested lungs
179
what are the causes of congestive heart failure?
CHD congenital heart disease, hypertension, valvular disease, arrhythmia
180
what is the link between left ventricular hypertrophy, coronary heart disease, renal failure, peripheral vascular disease, retinopathy, brain hemorrhage, stroke?
can all be caused by hypertension!
181
sequence of 4 events leading to heart failure
1. loss of myocardia efficiency
2. initiation of compensatory mechanisms (hypertrophy, dilation, tachycardia)
3. failure of compensatory mechanisms
4. heart failure
182
what causes left vs right ventricular hypertrophy?
LVH = hypertension
RVH + dilation = COPD
both can be caused by mitral valve disease
183
what is backward failure?
blood backs up into venous circulation
184
what is forward failure?
insufficient blood flow
185
what do both backward and forward failure lead to?
edema and congestion of tissue
186
what are the symptoms of backward and forward failure?
edema, cyanosis, dyspnea, orthopnea, fatigue, weakness, nocturia, increased venous pressure
187
what is a cardiogenic shock?
drop in blood pressure incompatible with life due to heart failure. caused by heart failure, most often LV
188
what % of CO is directed to the brain?
20%
189
what causes a stroke?
atherosclerosis in vessels leading to brain and ischemia
190
what is FAST (signs and symptoms of a stroke)?
Face dropping
Arm weakness
Speech difficulty
Time to call 911
191
what are the causes of intracranial hemorrhage?
hypertension, amyloid, ruptured aneurysms
192
where in the brain do aneurysms tend to occur?
circle of willis
193
what is treatment to avoid rupture (against intracranial hemorrhage)
coils inserted in the aneurysms to stabilize it
194
what is the risk with saccular aneurysm and subarachnoid hemorrhage?
if they rupture there is a 50% chance of death
195
which artery of circle of Willis is the most frequent site of damage?
middle cerebral artery
196
what are the consequences of an incident at the middle cerebral artery?
contralateral hemiplegia, hemianesthesia, speech impairment (half of the body is affected)
197
how can neuronal plasticity help after intracranial hemorrhage?
can rescue symptoms; possibility of functional recovery
198
what is multi-infarct dementia?
small areas of injury all over the brain (mini-emboli)
199
what are the risk factors for stroke?
elevated systolic blood pressure, diabetes, cigarette smoking, prior atrial fibrillation, prior CVD, alcohol, high cholesterol
