parsa Flashcards
What is the cause of most MIs, unstable anginas and sudden deaths? Why?
recent/partially stenotic artherosclerotic plaques
because they are softer and more susceptible to ACUTE PLAQUE CHANGE (change/rupture/hemorrhage). thrombus–> total or partial occlusion
What is the difference in causes of angina pectoris vs an MI?
angina=transient ischema ==> stable atherosclerosis
MI=acute plaque change with total thrombotic occlusion
What are the 3 types of angina?
stable: coronary stenosis, increased demand and decreased delivery, NO plaque disruption
prinzmetal or variant angina: vasospasm
unstable angina: acute plaque change with partial thrombosis and possible vasospasm and or embolism
How long does it take for irreversible injury to begin in ischemic cardiac myocytes? Which layer of the heart will be affected first?
20-40 minutes
subendocardium
What is the most common vessel involved in transmural infarcts?
LAD (40-50%) –> RCA (30-40%)
What treatment is important to prevent the progression of an MI?
reperfusion!!!
within 15-20 minutes to prevent all necrosis
within 2-4 hours to salvage some fibers
What is the appearance of a reperfused irreversible infarct? why?
hemorrhagic from the ischemic-injured microvasculature leaking when the flow is restored
contraction bands–> hyper contracted sarcomeres due to exaggerated contraction of dead fibers being exposed to high {Ca2+}
how can reperfusion injure cells?
due to the generation of oxygen free radicals (promoted by neutrophils and endothelial cells)
Which lab would be helpful in determining if a pt is having a second MI within a few days?
CKMB
What pathologic morphologic change can be seen in a pt who went through sudden cardiac death?
subendocardial myocyte vacuolization
What are the 3 factors that might trigger rupture of a plaque?
- adrenergic stimulation (highest 6am -12pm) –> cause systemic HTN and local vasospasm
- increased platelet reactivity –> occlusive thrombosis
- inflammation –> destabilize plaque
Are reperfusion consequences more or less with preconditions (previous angina)?
less
previous angina is protected
What is one of the most likely complications after an infarct?
papillary muscle rupture
What is the most common primary tumor in the heart?
Where is it normally located?
myxomas (benign neoplasms associated with abnormalities of chromosomes 12 and 17)
in the left atria
What is the most common tumor metastatic to the pericardium?
lung carcinoma
