Acute myocardial ischemia Flashcards
definition
ischemia that’s only lasted minutes to hours
or at most a few days
What can occur after only one minute of ischemia?
loss of glycogen
mitochondrial swelling
cellular swelling
loss of contractility
What may precede irreversible injury to myocytes?
fatal arrhythmia
What do the manifestations of acute myocardial ischemia look like with light microscopy?
Not visible. Generally myocytes look normal (they aren’t dead yet, but they don’t work)
Some manifestations don’t show up because they are functional, not structural
Some manifestations show up under electron microscopy
What happens if adequate blood supply is restored?
myocytes GRADUALLY recover contractile function
may take several hours, days, or weeks depending on severity of ischemia
Why do myocytes take longer time to recover?
accumullation of:
excess calcium
oxygen-derived free radicals
damage to cytoplasmic proteins and organelles
