Chapter 8: CAD Flashcards
What is ISCHEMIA?
Deficient oxygen supply to the myocardium resulting in transient or reversible injury to the myocardium
What CAUSES ischemia?
Partial occlusion of a coronary artery due to atherosclerotic plaque
How does ischemia appear on ECHO?
there is normal wall motion at rest but abnormal wall motion with stress/exercise
What is an INFARCTION?
Irreversible injury to the myocardium due to prolonged ischemia
What CAUSES infarction?
Acute thrombotic total occlusion at the atherosclerotic plaque (plaque ruptures and clots so heart muscle dies)
How does infarction appear on ECHO when ACUTE (happening rn)?
demonstrates abnormal wall motion at rest (hypokinetic, akinetic, or dyskinetic) and unaffected segments are hyperkinetic bc they’re trying to compensate for failing segments
Define AKINETIC
absence of inward endocardial motion or wall thickening in systole - not thickening at all, moving very little
Define DYSKINETIC
outward motion or “bulging” of the segment in systole instead of moving inward
Define ANEURYSMAL
the wall segment is dyskinetic and bulging out in systole and diastole
Define HYPOKINETIC
wall thickening looks reduced during systole but is not absent
What is RIGHT DOMINANCE?
when RCA gives rise to the posterior descending artery in 80% of people
What is LEFT DOMINANCE?
when circumflex gives rise to the posterior descending artery in 20% of people
What type of MI demonstrates HYPOKINESIS? & How does it appear?
- transient rest ischemia or NSTEMI
- less wall thinning/brightness
What type of MI demonstrates AKINESIS? & How does it appear?
- STEMI transmural
- wall thinning/brightness
What 3 things are used to rule in infarct in the ER?
( only 2 of the 3 needed)
- typical clinical presentation
- diagnostic ECG changes
- elevation in cardiac enzymes ( troponin, creatine, kinase)
When is echo for EVALUATION OF INTERVENTIONAL THERAPY done?
when patient went to cath lab to get intervention done
What are the 2 types of intervention?
- PCI (angioplasty/stent)
- CABG
Why is an echo for EVALUATION OF INTERVENTIONAL THERAPY done?
to assess its effectiveness
When should an echo for EVALUATION OF INTERVENTIONAL THERAPY be performed and why?
- several days post reperfusion therapy
- bc when blood is restored, “stunned” myocardium needs several days to respond
When is an echo for EVALUATION OF RESIDUAL IMPACT done?
4-6 weeks post MI
What are we looking at during an echo for EVALUATION OF RESIDUAL IMPACT?
we are looking at the status/extent of infarcted segments. so the degree of wall motion and scarring
What type of echo can we evaluate for hibernating myocardium?
echo for eval of residual impact
What is HIBERNATING MYOCARDIUM?
border myocardium that is chronically ischemic but not infarcted
How do we identify HIBERNATING MYOCARDIUM?
dobutamine stress testing: wall motion improves with a small dose and declines with higher doses
What complications of MI can we see on echo?
- MR
- ventricular rupture
- pericardial effusion
- RV Infarction associated with inferior LV infarct
- LV aneurysm
- LV thrombus
- Acute or End Stage Ischemic Cardiomyopathy
What can MR lead too?
- papillary muscle dysfunction
- rarely a partia or complete rupture of PM
- a new systolic murmur post MI
How does a rarely a partial/complete rupture of PM appear on ECHO?
flail leaflet with attached mass
What two types of ventricular rupture are there?
- ventricular septal defect
- ventricular free wall rupture
Ventricular septal defect is due to what?
necrosis then rupture of a focal area of the IVS
Rupture of focal area of ventricular free wall is due to what?
due to blood into pericardial sac
How can ruptures be temporarily contained?
by a pseudoaneurysm that is preventing free flow of blood into pericardial sac
How do you identify a pseudoaneurysm?
- wall is composed of pericardium
- narrow neck
- abrupt
- typically thrombus filled
- harsh transition from myocardium to nothing
When is PERICARDIAL EFFUSION seen?
- 2-4 days after MI
- in transmural, large or anterior MI
What is PERICARDITIS?
small to mod amount of fluid in pericardial sac accompanied by chest pain and ECG changes and is response to injury
What is DRESSLER’S SYNDROME?
delayed form of pericarditis (weeks to months) & is an autoimmune response to the altered myo/pericardium
What occurs during DRESSLER’S SYNDROME?
- antibodies attack the area and cause inflammation and fluid accumulation
- patient has chest pain and fever
Why does Right Ventricular infarction associate with Inferior LV infarct?
Proximal occlusion of RCA impacts inferior LV and RV bc it feeds both
A LV Aneurysm is due to what?
extensive damage of thinning dyskinetic walls creating distinct outpouching of an area of the ventricle
How does a LV Aneurysm appear?
- Wall is a thin layer of myocardium
- Neck is wide
- smooth transition from normal to thin myocardium
What type of aneurysms are the most common?
apical aneurysms
How does an LV THROMBUS form?
Akinetic walls → stasis of blood → clot protruding or laminated against wall
What increases the likelihood of a LV THROMBUS?
- Poor LV function
- Aneurysm
- Akinetic area
- Spontaneous contrast
How can we differentiate a LV THROMBUS?
looking for an area of different echogenicity, distinct from the endo
What happens when a THROMBUS embolizes?
- LV stroke
- pulmonary embolus of RV
What is Acute or End Stage Ischemic Cardiomyopathy?
severe LV dysfunction and dilation due to an acute multi vessel or proximal event or many ischemic events over time
What is a Non-ischemic cardiomyopathy?
poorly functioning ventricle that is not due to CAD or valvular disease but to other infection, virus or toxin
