Mechanism of Stroke

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Simusid

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here is my dumb EMT-B question of the day. Stroke mechanism vs MI mechanism. In an MI, a plaque breaks free and causes rapid clotting at the site. I was re-reading about a-fib and the comment that "The biggest danger from A-Fib is stroke. Because your heart isn't pumping out properly, blood can pool in your atria, particularly in the Left Atrial Appendage. Blood clots can form and travel to the brain causing stroke."

There's no mention of an atherosclerotic clot in the brain breaking free and causing a thrombolytic clot. Does that happen?
 
Yes, it can and does.


A fair number (if not most, but I don't have stats) of stroke patients do not have a history of A-fib.
 
Simusid said:
here is my dumb EMT-B question of the day. Stroke mechanism vs MI mechanism. In an MI, a plaque breaks free and causes rapid clotting at the site. I was re-reading about a-fib and the comment that "The biggest danger from A-Fib is stroke. Because your heart isn't pumping out properly, blood can pool in your atria, particularly in the Left Atrial Appendage. Blood clots can form and travel to the brain causing stroke."

There's no mention of an atherosclerotic clot in the brain breaking free and causing a thrombolytic clot. Does that happen?
Click to expand...
^^^ What Linuss said.

I would also add as a little educational extra that there are multiple pathologies of MI and stroke. To say that an MI or Stoke is only caused by emboli or thrombus secondary to plaque or is an over-simplification and may confuse you later on when someone gets in an MVA and dissects a vertebral artery and looks like they are having a stroke but is an otherwise healthy 20-something yro.
 
Simplificatin' .

Two types of CVA (cerebro-vascular accident, intracranial infarct): bleeders (rupture of a blood vessel causing tissue irritation and sometimes pressure, but always tends to deprive the artery's intended destination tissue of circulation) and blockers (clots or other embolii).
Generally, CVA's are considered to be independent of head trauma (that has its own set of subsets, a'la Natasha Richardson).

Intracranial atherosclerosis article: http://www.medscape.com/viewarticle/730742

Not good.

Differential effects upon pre-hospital care: at root, not much, since a scan is needed to differentiate the two and dictate whether a "clot buster" Rx can be used, or surgery is needed, or they need monitoring and a careful dose of "wait and see" applied. Oxygen, sit up, record data and hx, didi mau to CVA treatment center. Get a line in and watch for seizures. Be ready to guard airway. See local protocols. Reassure the pt!!

Otherwise seemingly health individuals can drop from a CVA. Arteries ascending to the head can suffer insults which cause global or hemiglobal CVA-like affect and effect (a'la Robert Heinlein). Mostly the source of embolii has to start at the left side of the heart because most stuff big enough to block a cranial arteriole would block a pulmonary one if it came from the right side.
 
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