rhan101277
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I wouldn't use the word fascicle, since it's easily confused with the branches of the His-Purkinje system (unless that's what you were talking about).
Ischemia frequently causes wall motion abnormalities (hypokinesis, akinesis, dyskinesis) that can effect pumping ability.
An occlusion 'higher up' in a coronary artery (proximal occlusion) threatens more of the myocardium, since all the distal branches are affected. So a proximal occlusion of the RCA causes injury to the inferior wall of the left ventricle the same way an occlusion half way down would. It also causes injury to the right atria and right ventricle, because the occlusion is 'higher up'.
Ischemia generally extends from the endocardium to the epicardim (inside out) as the ischemic zone extends over time. By the time it reaches the surface, it's considered a 'transmural' infarct. This can weaken the ventricular wall to the point where it ruptures.
By the 3-6 hour mark, serious and irreversible damage is done to the heart (assuming the absence of robust collateral circulation).
Time is muscle.
Thanks for that great description. I thought individual muscle bundles were called fascicles, or is that just for skeletal muscle and not cardiac muscle.