L16 Ischemic Heart Disease

if tropinin is high, the diagnosis is... is troponin is not high, the diagnosis is...

-NSTEMI(non-ST-segment elevation myocardial infarction) -unstable angina

acute consequences of myocardial infarction

-coagulative necrosis of myocardium -damaged conduction system -perforation, etc.

how does endothelial cell injury lead to atherscloerosis?

-monocytes enter subintimal space and turn into macrophages -macrophages take up modified LDL and become foam cells -initial lesion

how do fatty streaks progress to plaques

-smooth muscle cells enter subintimal space and act as fibroblasts -smooth muscle cells take up modified LDL and turn into foam cells

what are smaller causes of myocardial infarction?

-vasospasm -emboli -small blood vessel disease

if an aneurysm does develop, what are the common sites for them?

CNS vasculature abdominal aorta peripheral arteries

what is the cap made of?

ECM (collagen, elastic fibers, proteoglycans) cells (smooth muscle cells, macrophages, T cells)

if a patient with ACS has an EKG with a ST segment elevation, what is the diagnosis?

STEMI (ST segment elevation myocardial infarction)

what is an aneurysm?

a pathological dilation of a blood vessel due to weakening of the media

an atheroma is also called...

a plaque

what is atherosclerosis?

a vascular disease characterized by intimal atheromas

______________ refers to a constellation of clinical symptoms caused by acute myocardial ischemia

acute coronary syndrome (ACS)

acutely symptomatic IHD patient presents with...

angina pectoris acute coronary syndrome sudden death

instantaneous consequences of myocardial infarction

arrhythmia->death

clinical manifestations of ischemic heart disease?

asymptomatic acutely symptomatic chronically symptomatic

2 of the 4 leading causes of death is caused by...

atherosclerosis

what happens in ventricular aneurysm?

blood that is just sitting there

what happens in a left ventricular cardiac rupture? what is this called?

blood will accumlate in the pericardium and put pressure on the heart so it cant fill (pericardial tampanade)

anatomy of the atheromas

cap shoulder core

principle components of atherosclerotic plaque

cells ECM lipids

what is angina pectoris?

chest pain

chronic consequences of myocardial infarction

chronic IHD

what is a myocardial infarction?

coagulative necrosis of myocardial cells

chronically symptomatic IHD patient presents with...

congestive heart failure

what are the causes of ischemic heart disease?

coronary artery narrowing (90%) microvascular/endothelial dysfunction (10%)

what childhood findings can predict atherosclerosis?

coronary artery streaks

in the absense of thrombosis, who is more likely to be symptomatic: non-critical stenosis or critical stenosis

critical stenosis

if a pt with ACS has an EKG without an ST segment elevation what is the dignosis?

depends on troponin

the initial atherosclerotic lesion is called...

fatty streak

the plaque is made up of...

foam cells (from SMC and macrophages) cholesterol CT matrix

what is modified LDL

glycated LDL or oxidized LDL

chronic ischemia heart disease can lead to...

heart failure

what conditions can cause aneurysms?

hypertension atherosclerosis

what kind of cells in the shoulder?

inflammatory cells

which is worse? ischemia or hypoxia?

ischemia

how is coronary artery atherosclerosis most commonly manifested?

ischemic heart disease

would the entire endocardium infarct or would it be a portion?

it would be the whole thing

is arterial stenosis an early finding or a later finding in atherosclerosis?

late finding

when do plaques typically undergo calcification?

later in coronary artery disease

what is found in the core?

lipids proteins cells

a stroke will manifest as...

liquefaction necrosis

what is a fatty steak?

macrophages packed with lipids as foam cells

what does sudden cardiac heart result from?

myocardial infarction ->arrhythmia ->death

what is ischemic heart disease

myocardial ischemia caused by more oxygen demand than oxygen supply

the core of the atheromas is typically....

necrotic

what is it called if blood vessels grow into the plaque?

neovascularization

does the vessel reduce in size at the beginning as the plaque grows?

no, plaque just keeps getting bigger

what can cause mitral valve regurgitation?

papillary muscle infarction causing mitral valve insufficiency

atheromas has what on it?

raised focal lesions, eccentrically located (more on the sides)

what are the adverse outcomes of aneurysms?

rupture dissection (into media) hemorrhage (after dissection)

fractures of a plaque is most common at...

shoulder

2 types of angina pectoris

stable-reproducible with reproducible factors unstable- new onset, increasing frequency/severity

what can happen if the atherscloerosis does not fracture?

stenosis possibly causing ischemia

1st wave of increasing necrosis during MI

subendocardial necrosis b/c farthest away from blood supply

what causes atherosclerosis?

sustained injury to endothelium leading to inflammation

what happens if the cap fractures?

the core can be released and lead to a thrombosis

which causes a larger area of infarction: thrombosis of a critically-narrowed artery or a non-critically-narrowed artery?

the non-critical stenosis b/c at that point, no collaterals have formed

what is an erosion?

the surface is sloughed away- still can possibly cause a thrombosis

what happens if plaque undergo fibrosis?

they become less likely to fracture but harder to destroy with angioplasty (less reversible)

a plaque that has..........is considered a vulnerable or unstable plaque

thin cap (more likely to fracture) and large lipid core (if it does fracture, you have more probability to thrombose)

what features of the plaque determine the likelihood of fracture?

thinner cap more inflammation composition of the core (soft plaque=more thrombosis, fibrous plaque=less thrombosis)

what could be done to reduce the infarct size during MI?

thrombolysis angioplasty coronary artery bypass

what is the most common cause of myocardial infarction (90%)?

thrombosis of a coronary artery

what can happen if the atherosclerosis fractures?

thrombosis possibibly leading to infarction

what happens in a mural thrombus?

thrombus in the endocardium- can break loose and possibly go to the brain

once more than 50% of the subendocardial necrosis has occured, it is called...

transmural necrosis

t/f the core is thrombogenic

true

subtypes of myocardial infarction (MI)

type 1- obstructed flow type 2- inadequate perfusion

what is one of the body's responses to heart failure

water retention (aldosterone and ADH increases)

what is considered critical stenosis?

when the vessel is 75% of it's original size