coronary heart disease Flashcards
this disease is caused by plaque buildup in the wall of the arteries that supply blood to the heart (called the coronary arteries).
coronary heart disease
a chronic complication of an acute disease
sequelae
what are common sequelae of coronary heart disease
-angina pectoris
-myocardial infarction (heart attack)
-dysrhythmias
-heart failure
-sudden cardiac death
alternate or “backup” blood vessels in your body that can take over when another artery or vein becomes damaged
collateral circulation
what are some common causes (etilogy) of coronary heart disease?
-known risk factors
-atherosclerosis with narrowing of the arterial lumen (thrombus formation)
-coronary vasospasm (temporary constriction of vessel bringing blood to heart)
-endothelial cell dysfunction
-left ventricular hypertrophy
what are some uncommon causes (etiology) of coronary heart disease
-emboli (a blood clot that moves through vessels until it reaches a vessel that its too small to travel through)
-respiratory failure
-anemia
-hypovalemia
what are some congenital causes (etiology) of coronary heart disease?
-LADCA (left arteriole descending coronary arteries) originating from the pulmonary artery
what lipoproteins are associated with a greater risk of atherosclerosis
LDL and VLDL
this lipoprotein transports cholesterol from peripheral tissue back to the liver, clearing any plaques
HDL
what is the desirable level of cholesterol?
<200mg/dl
at what level of cholesterol does an individual become at risk?
> 240mg/dl
what level of HDL cholesterol is low to desirable
<40mg/dl
what level of LDL cholesterol is desirable
<130mg/dl
which type of artery is atherosclerosis most likely to occur?
epicardial arteries
true/false: epicardial arteries are involved in microcirculation
false - involved in macrocirculation
what is the main stimulus for vasomotion in epicardial arteries?
flow
what is the main function of the epicardial arteries?
transport
do epicardial arteries have a relatively low or high resistance to blood flow
low
what is the main stimulus for vasomotion in small arteries?
pressure
what is the main function of small arteries?
regulation
do small arteries have a relatively low or high resistance to blood flow/
higher than epicardial arteries but lower than arterioles
what is the main stimulus for vasomotion in arterioles?
metabolites
what is the main function of arterioles
regulation
do arterioles have a relatively low or high resistance to blood flow?
high
what is the main function of capillaries
exchange
do capillaries have a relatively low or high resistance to blood flow
low
risk factors, such as high LDL, hypertension, DM, and cigarette smoking, disrupt normal functions (e.g. local control of vascular tone, maintenance of antithrombin surface and control of inflammatory cell adhesion and diapedesis) of the vascular epithelium which causes _________
coronary atherosclerosis
what do functional changes of the vascular endothelium cause?
a buildup of fat, smooth muscle cells, fibroblasts and intracellular matrix that make the atherosclerosis plaque.
what does the loss of vascular endothelial defences cause?
-inappropriate constriction
-luminal thrombus formation
-abnormal interactions between blood cells and the activated vascular endothelium.
Why does the velocity of blood flow decrease greatly in the capillaries and then increase in the veins?
blood flow is slowest in the capillaries to allow for exchange of nutrients.
coronary _____ can be altered by:
-large, stable atherosclerotic plaque
-acute platelet aggregation and thrombosis
-vasospasm
-failure of auto regulation of the microcirculation by endothelial cell damage
-poor perfusion pressure (hypovalemia)
perfusion
in coronary heart disease, is oxygen supply or demand increased?
demand
what are clinical presentations of coronary heart disease?
- angina pectoris
-chest pain
-sob
-diaphoresis (sweating)
-nausea and vomiting - physical exam
-4th heart sound
-congestive heart failure
-shock
chest pain is asymptomatic in 70-80% of people. when chest pain is present, what is it mediated by?
sympathetic afferent nerves
________ may induce chest pain in at least two ways, either by direct stimulation of sensory afferents before actual ischemia occurs or secondary to ischemia.
adenosine
this is an adenosine receptor blocker, therefore can be used to treat chest pain associated with coronary heart failure
aminophylline
what is the pain pattern associated with coronary heart failure explained by?
convergence
it is possible that plaques may rupture or become eroded. what are some characteristics of vulnerable plaques?
-large lipid core with thin cap
-fissured or ruptured cap
-active inflammation within the plaque
-epithelial denudation with platelet adherence
this type of plaque has a thin fibrous cap, collagen-poor fibrous cap, large lipid core, many macrophages and fibrin-rich thrombus
ruptured plaque
this type of plaque is protcoglycan and glycosaminoglycan rich, little or no lipid core, neutrophils and NETs, many smooth muscle cells and platelet rich thrombus
eroded plaque
true/false: in acute coronary syndrome, chest pain is usually more severe and lasts longer than typical angina
true
during plaque erosion or rupture, the occlusion/blockage is only partial
unstable angina (still have blood flow to keep myocardia alive)
during plaque erosion or rupture, the occlusion/blockage is complete
MI
in acute coronary syndrome, if the ___________________ are affected you will get severe cardiac failure – hypotension —- shock
left main coronary and left anterior descending arteries
in acute coronary syndrome, if the ____________________ are affected you will see pericardial effusion —– tamponade (heart cannot contract thus, fluid in pericardial space) and mitral valve damage
circumflex coronary and left anterior descending arteries
in acute coronary syndrome, if the ________ is affected you will see AV node affected —- bradycardia
posterior ventricular artery
in acute coronary syndrome, if the _________ is affected (which it rarely is) you will see irrigation by the right and left sinuses
sinus node
what are the immediate effects of acute coronary syndrome?
MI leads to a drop in cardiac output triggering activation of the sympathetic system - therefore an increase in HR, BP and contractility
when an MI occurs and there is a decrease in stroke volume, what are the two ways we can get immediate time increase in stroke volume
- baroreceptor activation and therefore activation of sympathetic NS
- decrease in renin perfusion and RAAS activation
what enzymes are increased when cells are totally ischemic
CK-MB, lactate dehydrogenase (LDH) and troponin
is there ST changes on ECG for partial or total ischemic cells
partial
are dysrhythmias associated with partial or total ischemic cells?
partial
if a patient presents with signs and symptoms of cardiac ischemia, has ST elevation, + biomarkers, what is their diagnosis?
ST elevation MI (STEMI) -treated with a stent
if a patient presents with signs and symptoms of cardiac ischemia, has no ST elevation, - biomarkers, what is their diagnosis?
unstable angina
if a patient presents with signs and symptoms of cardiac ischemia, has no ST elevation, + biomarkers, what is their diagnosis?
no ST elevation MI (NSTEMI) - treated with meds
will LDH levels be increased to decreased during a myocardial infarction
increased
troponin serum levels rise ____ hours after the occurrence of cardiac symptoms in patients with acute MI
3-4
________ are usually the primary cause of sudden cardiac (e.g. v-fib)
ventricular arrhythmias
