What is the number one cause of death in the U.S.?
Heart Disease
Dominant cause of ischemic heart disease is?
insufficient coronary perfusion (due to narrowing of epicardial coronary arteries)
T/F Most ischemic heart disease has an asymptomatic phase?
T
[sudden cardiac death is first symptom in 50%!]
When do coronaries fill? Tachycardia does what to this
- diastole
- Reduces filling
Review coronary anatomy!
- LMA->LCX (plus OM1 & 2)
- LMA->LAD (Plus D1, D2)
- RCA->PL and PD
total occlusion of what branch takes out 15% of Left Ventricle? 35%? 50%?
- LCX (left circumflex)
- RCA
- LAD
Plaques are found at which location in LCA? Which location in RCA?
- proximal LAD and LCX
- Entire length of RCA
Soft plaques are made of?
necrosis
Hard plaques are made of?
fibrocalcific substance
Coronary occlusion grading follows what scale? When is it considered symptomatic?
-Less than 25% occluded= Grade 1
-26-50%=Grade 2
…and so on
-Grade 4 is considered “severe” and has symptoms
Severe left main artery disease has what prognosis?
high rate of sudden death. [usually occurs w/ severe 3-vessel disease]
Little white chunks in a coronary artery seen on X-ray is called what?
plaque calcification
T/F collateral arteries dilate and grow when stimulated by downstream ischemia?
T. [non-functional normally though]
T/F chronic coronary lesions typically can vasospasm or hemorrhage?
F, chronic are typically stable, slowly enlarging.
-Acute are rapidly enlarging, prone to rupture at any grade, thrombose, hemorrhage, and vasospasm (endothelial injury)
Am I typical of chronic or acute coronary lesions: unstable angina?
acute
Am I typical of chronic or acute coronary lesions: asymptomatic ischemic heart disease
Both!
Am I typical of chronic or acute coronary lesions: stable angina
chronic
Am I typical of chronic or acute coronary lesions: myocardial infarction
acute
Am I typical of chronic or acute coronary lesions: Heart failure
- chronic heart failure in chronic coronary lesions, while…
- acute heart failure in acute coronary lesions
Am I typical of chronic or acute coronary lesions: sudden death
acute
what 3 fates can occur after a CORONARY plaque rupture?
- healing
- embolism
- thrombosis (most common & clinically significant! More than embolism.)
what 3 fates can occur after a CORONARY plaque rupture which leads to THROMBOSIS?
- organization (Most common!!)
- embolization
- obstruction
Plaque progression is which? a)more fat deposited OR b)repeated episodes of plaque rupture, thrombosis, organization
B.
T/F plaque instability can occur an any stage of narrowing?
T
Hemorrhage within a plaque may lead to?
-acute coronary syndrome (possibly by inducing vasospasm)
concentric plaques are nice, because they prevent?
vasospasm
Ischemia is defined as?
- myocytes remain viable
- sublethal
[may produce angina, arrhythmia, or heart failure!]
acute ischemia looks like what on histo?
normal myocytes OR with contraction bands
chronic ischemia looks like what on histo?
vacuolated myoctyes w/ decreased contractile elements
Infarction is defined as?
-non-salvageable myocytes
Acute infarction looks like what on histo?
coagulative necrosis w/ contraction bands, apoptosis, wavy fibers. Depending on time afterward: neutrophils, macrophages, granulation tissue, scarring
_________ myocardium is most susceptible to ischemia
subendocardial
As ischemia/infarction progress, they expand in what directions?
radially outward, and transmurally toward the epicardium
How many hours of severely reduced perfusion result in permanent damage?
this is weird but…
-“at least 2 to 4 hours” (“necrosis is usually complete within 6”)
What is the wavefront phenomenon?
progression of MI from subendocardial to transmural
What type of MI result in relatively discreet infarcts and occur in very specific locations?
acute MI associated with coronary artery occlusion
What type of MI is circumferentially distributed around the LV?
acute MI associated with global hypoperfusion
What type of infarcts are found in embolic disease?
focal acute MI that may not be subendocardial and are not in specific coronary distribution
What type of MI is STEMI?
transmural
What type of MI is non STEMI?
subendocardial
Is transmural or subendocardial more common?
transmural [involves half of myocardial thickness]
How does a subendocardial MI occur?
rapid lyses of coronary thrombus or prolonged hypo perfusion of heart
When do macrophages start cleaning up an MI inflammation? granulation tissue?
8-11 days
11-14 days
When does collagen deposition take place?
day 14+
When does death of neutrophils take place?
5-7 days
What does a week one MI infarct look like?
begins dark mottling
yellow-tan from increasing neutrophils/necrosis
border of infarct stays hyperemic
What is karyorrhectic debris symbolic of in MI recovery?
neutrophils starting to die
What does a week two MI infarct look like?
center is maximally yellow tan and soft with a depressed red/gray border of granulation
Which direction of clean up takes place?
outside in,
What cells are a main component of granulation tissue that you should be able to point out
fibroblasts (residual chronic inflammatory cells too)
What does a week 3-4 MI look like microscopically?
fibrosis with numerous fibroblasts, pink collagen, and very sparse chronic inflammatory cells
What color is collagen in trichrome?
blue
Review the following list of complications of MI
arrhythmias, contractile dysfunction, rupture, RV infarct, expansion, extension, aneurysms in the ventricle, thrombus, progressive late heart failure, pericarditis
What are the 4 main outcomes of electrical failure following MI?
acute arrhythmias
non-lethal
arrest- resuscitated
sudden death
What are the 3 outcomes of pump failure following MI?
acute HF
cardiogenic shock [>40% LV loss]
chronic HF
When is myocardial rupture most common?
3-7 days post MI, correlates with maximal degradation`
Is a free wall rupture fatal?
rapidly
Papillary muscle rupture commonly leads to what?
acute mitral regurg
Is the free wall rupture most common?
Yes- anterolateral wall
What are the risk factors of myocardial rupture?
> 60 years old Female>male chronic hypertension No LV hypertrophy FIRST MI !!!!!!!!!![no scars that block]
Is there high mortality in rupture of ventricular septum?
Yes- this is why we repair it. Acute L>R shunt
What location does papillary muscle rupture occur most?
post-medial
Is infarct extension or infarct expansion more commonly associated with mural thrombus and poorer prognosis?
Infarct expansion
What are the 3 main consequences of aneurysm in the myocardial wall?
-arrhythmias
-mural thrombus
-chronic heart failure
[no rupture after 1 mo]
What is chronic ischemic heart disease also known as? What is commonly seen 6 (for review)?
- ischemic cardiomyopathy
- progressive heart failure, previous coronary arterial interventions, LV hypertrophy and dilatation, discreet scars, thickened endocardium, thrombus often.
What syndrome is pericarditis following MI? how many days after MI? occur only after transmural MI?
Dressler’s, day 2 or 3, yes