Coronary artery disease and myocardial ischemia Flashcards
what is the major model for ASCVD?
response to injury
which cells can become foam cells in the pathogenesis of atherosclerosis?
SMCs
macrophages
what is the advanced lesion in atherosclerosis?
fibrous plaque
what are the mechanisms of enhanced atherosclerosis in the context of smoking?
hemodynamic stress (increased HR and BP)
endothelial injury and dysfunction (inhibit NO)
atherogenic lipid profile
enhanced coagulability
arrhythmogenesis
relative hypoxia (CO)
what are the associated outcomes of coronary atherosclerosis?
acute coronary syndromes
sudden death (primary VT/VF)
dilated (ischemic) cardiomyopathy
atrial fibrillation / flutter
what is the cause of prinzmetal angina?
sudden loss of supply due to coronary artery spasm
what are the features of angina pectoris?
heavy, pressue, band-like, crushing
OFTEN SILENT
what are the features of unstable angina?
new onset
subjectively worse discomfort
onset with less activity
angina at rest (“angina decubitus”)
how long does classic angina pectoris last? what is the onset like?
less than 30 m
usually gradual
what agents are used for pharmacological stress testing? what are the MOAs?
adenosine - vasodilate, increase HR
dipyridamole - vasodilate, increase HR
dobutamine - increase contractility, increase O2 demand
what signs indicate positive stress tests?
ST segment shifts
ST downsloping of more than 1mm at 80 ms after J point
symptoms (angina)
VT
what tests increase the predictive power of stress testing?
imaging (echo or nuclear)
why does irreversible injury (infarction) occur?
depletion of high energy phosphate bonds
ATP is not replaced
sarcolemmal gradients of Na, K reduced
what methods can be used to increase oxygen supply in myocardial ischemia?
reperfusion
coronary vasodilation
what methods can be used to decrease oxygen demand in myocardial ischemia?
beta blockers
decrease BP
reduce preload (diuretics, nitrates)
reduce circulating catecholamines
