CABS Cardiac Ischemia Flashcards
Hyperlipidemia - two types are
Hyperlipidemia two types primary - familial
secondary - acquired (dietary, medication, DM)
Atherosclerosis is
hardening of the walls of the vessels such that they become less compliant, can restrict blood flow
The walls of the vessels are made up of what layers? (3)
tunica intima
tunica media
tunica externa - contains vasa vasorum
The tunica intima is?
inner layer of simple squamous endothelium - contains properties discussed in heme
The tunica media is?
smooth muscle layer, under autonomic control
The tunica externa is?
connective tissue layer
contains vasa vasorum - vessels that feed the layers of the thicker/ larger vessels
Atherosclerosis occurs within the ________ of the arteries.
________ cells will accumulate in this layer. Typically form in areas where there is repetitive ________ to the vessel wall
intima
foam cells
injury
Foam cells are?
lipid filled macrophages
_______ inflammatory states, __________ risk of atherosclerosis
increase
increase
First stage in development of atherosclerosis is
fatty streak
Development associated with stressors, increased
lipid deposition in the subendothelial space, increases proinflammatory mediators
fatty streak
within the fatty streak the muscle cells undergo
apoptosis
accumulation of monocytes that are engorged with cholesterol (foam cells) creates …
atherosclerotic plaques
after foam cells die and necrotic core develops smooth muscle cells will …
invade the intima increasing size of the plaque
the thinner vessels created secondary to this disease process (atherosclerosis) are more likely to
rupture
Cellular components of the atherosclerotic plaque include
macrophages
smooth muscle cells
Extracellular components of the atherosclerotic plaque include
lipids
Increased turbulence leads to increased pressure which can lead to increased ______ of the capsule wall
thinning
Ischemia is
decreased blood flow leading to hypoxia
Infarction is
blood flow is cut off leading to necrosis (cellular death)
Coronary vessels fill during
diastolic relaxation
Left coronary artery branches into
left circumflex
Left anterior descending
Left circumflex feeds the
anterior wall and lateral wall of the heart
Left anterior descending feeds the
anterior and septal aspect of the heart
Right coronary artery feeds the
right side of the heart and some of the inferior aspect of left ventricle
conduction system
Angina is
chest discomfort (heavy, pressure, tight) located substernal or slightly to the left
Myocardial Ischemia is
oxygen demand of the cardiac muscle outweighs the oxygen being delivered
supply and demand mismatch of O2
Stable angina is
history of reproducible angina (exercise induced myocardial ischemia)
discomfort comes on a routine/ expected intervals
Stable angina: sx last less than ______ minutes once provocative activity has stopped
20
Acute myocardial infarction types (1&2)
Type 1 = d/t coronary atherothrombosis (unstable plaque that opened up)
Type 2 = d/t supply-demand mismatch (arrhythmia, septic, pH is off, etc)
ACS Pathophysiology
plaque rupture
thrombogenic substrates released
activation of platelets
coagulation cascade
Unstable angina is
new-onset angina or change in precipitating factors
(takes less exertion/ stress to induce sx than previous, may occur at rest)
no necrosis =
unstable angina
necrosis =
AMI (acute myocardial infarction)
Acute myocardial infarction may lead to
decreased contractility which will further decrease profusion
includes STEMI and NSTEMI
NSTEMI is m/c d/t
disrupted atherosclerotic plaque or partial blockage
NSTEMI on ECG looks like
new horizontal or downsloping ST segment < 0.5 mm
T wave inversion > 1mm
(ST depression or inverted T wave) in 2 continuous leads
STEMI typically begins with
atherosclerotic plaque rupture
STEMI has ________ myocardial ischemia
transmural (complete obstruction of flow)
STEMI on ECG looks like
ST elevation in two continuous leads (needs to be leads V2 and V3 - 2 mm elevation) J point is elevated above the isoelectric line
Right ventricular infarction is associated with occlusion of what artery
right coronary artery occlusion
Right ventricular infarction will have elevated ______ and decreased ______ d/t decreased ______ filling
JVP
CO
LV
Right ventricular infarction is _____ STEMI
inferior
(ST elevation V1, 2, 3 and ST depression in V2)
STEMI mimics =
Acute pericarditis - will show ST elevation in all the leads though
Myopericarditis - usually viral or autoimmune
Left ventricular hypertrophy
Aortic dissection
Severe hypercalcemia (electrolyte abnormalities)
Coronary Vasospasm is
diffuse or focal spasm of the coronary arteries due to hyperactivity of smooth muscle (causes them to clamp down)
Presents like a STEMI (transient ECG findings)
may occur at rest
Coronary Vasospasm tx
nitro STAT
call cath lab
Coronary vasospasm trigger (drugs?)
cocaine, marijuana, ETOH, amphetamines
Complications of ischemia include
decreased CO - decreased BP
Arrhythmias (m/c afib)
Blocks
Cardiogenic shock
Acute mitral regurg
Papillary muscle dysfunction can be a complete or partial
rupture
Papillary muscle dysfunction: Most common at the __________, causes _________.
posteromedial papillary muscle, causes acute mitral reguargitation
Rupture of the wall is defined by
tear in the infarcted myocardium, typically occurs 72 hrs - 4 days after initial infarction
Ventricular aneurysm is
complication of acute myocardial infarction, infarcted area of ventricle weakens, chamber will enlarge, overtime will scar and calcify
decreased CO and contactility –> hypotension
Mural thrombi is m/c w/
anterior STEMI (LAD)
Mural thrombi is associated with pts who have suffered with
apical aneurysm –> poor contractility of the apex with relative blood stasis
Mural thrombi leads to
arterial embolic events
