ischaemic heart disease Flashcards
what are the two kinds of ischaemic heart diseases?
chronic coronary artery disease (CAD)
acute coronary syndrome (ACS)
what is the goal for patients with chronic CAD?
maintain balance between myocardial oxygen supply and demand
what is the goal for patients with ACS?
to restore or keeping open the coronary artery lumen
what causes symptoms of CAD and cardiac abnormalities?
hyperaemic stress
coronary flow reduction and endothelial dysfunction
what are the two vessels in coronary vasculature?
large, proximal epicardial vessels, and small,
distal endocardial vessels
what happens in epicardial vessels during disease state?
artery blood flow is limited by the extent of epicardial vessel stenosis
what is atheroma?
lesion that forms in vasculature leading to occlusion
what are the symptoms on angina pectoris?
result of myocardial ischaemia causing discomfort in chest
what is chronic CAD associated with?
the build up of atheroma in epicardial coronary arteries
what is Atherosclerosis?
hardening of arteries with gathering of fatty deposits in tunic media and tunica intima
what is Atherosclerosis a response to?
injury and perpetuation of inflammatory response
what other arteries can atherosclerosis effect?
carotid arteries
peripheral artery disease
what does endothelial dysfunction mean?
pathologic endothelial cell regulation which is caused by abnormal vascular tone and pro-thrombotic properties
what does endothelial damage cause?
decreases antiplatelet and anticoagulant mechanisms
what can cause an inflammatory response?
infiltration of myocytes and differentiation to macrophages
what are symptoms of Atherosclerosis?
‘Distinctive plaque with necrotic core/fatty acid deposition, foam cells, fibrous cap’
when do you see Acute coronary syndromes (ACS) ?
fissuring or rupture of atherosclerotic
plaques
what are the three types of acute coronary syndrome?
unstable angina, non-ST elevation MI, and ST elevation MI
when does a non-ST elevation myocardial infarction occur?
when unstable plaque ruptures but doesn’t completley close up the epicardial
coronary artery
how is mortality in STEMI reduced?
relief of obstruction
what are the treatments for ischaemic heart disease?
focus on reduction of myocardial oxygen demand
β1-adrenoceptor antagonists
Organic nitrates
Sublingual nitroglycerin tablets
what do β1-adrenoceptor antagonists do?
reduce myocardial oxygen demand by reducing heart rate and contraction
what do organic nitrates do?
dilation of peripheral capacitance veins, decreasing preload wchih reduces myocardial oxygen demand
what do Sublingual nitroglycerin tablets or nitroglycerin sprays?
immediate release of exertional angina
what is the challenge of long term use of nitrate?
tolerance
what do calcium blockers do?
decrease calcium influx causing reduction in contraction of myocytes and vascular smooth muscles which decreases oxygen demand
also causes systemic vascular resistance
where are Thrombolytics used?
‘pharmacologic management of STEMI’
what are lipoproteins?
‘macromolecular aggregates which transport triglycerides and cholesterol in the blood’
triglycerides and cholesterol contained in the hydrophobic core
what are Apolipoproteins?
insert themselves into the coat of lipoproteins stabilizing them and acting as ligands
what happens during cholesterol transport?
binding of apolipoprotein B100 to LDL receptors encouraged LDL internalization of vesicles and fusion of vesicles with lysosomes
LDL reecptors recycled to surface
lipoprotein particles are hydrolyzed to amino acids
decrease in activity of enzyme controlling cholesterol synthesis
increase Cholesterol storage and export
decrease Uptake of LDL
what are the problems with elevated LDL?
transforms into oxidized LDL which effects vascular function
what is a widely used treatment for hypercholesterolemia?
‘statins which reduces the extent of hepatic cholesterol synthesis’
what is the result in reduction in the extent of hepatic cholesterol synthesis?
‘increased hepatic LDL receptor expression increases clearance of cholesterol containing lipoprotein particles from the
bloodstream’
what are the causes of heart failure?
coronary artery disease
Cardiomyothopathies
Hypertension
Valve diseases
Arrhythmias
