Myocardial Infarction Flashcards
What is a STEMI?
What percentage of MIs are STEMIs?
ST elevation myocardial infarction = when coronary flow is completely occluded
30%
What does a partial occlusion cause?
UA or NSTEMI
What is stable angina vs unstable angina?
stable = known CV disease that hasn’t worsened/relieved
unstable angina = new/ worsening
What characterizes a non-STEMI?
ST segment depression, T wave inversion
chest pain
elevated cardiac enzymes
What characterizes an NSTE ACS?
Non ST Elevation acute coronary syndrome
ST depression w/ T wave inversion
normal cardiac enzymes
What characterizes a STEMI on EKG?
ST elevation of 2 mm or more
1.5 mm or more in woman
What do T wave changes indicate?
deficient blood supply and impaired repolarization = ischemia (subendocardial)
What do ST Segment shifts indicate?
deficient blood supply and inability to fully polarize = injury
what do inverted/abnormal Q waves indicate?
dead tissue and lack of depolarization = infarction
What would you see in a subendocardial ischemia?
usually ST depression, but sometimes elevation
T wave inversion
What would you see the first day of an an MI where ischemia and injury extend into the epicardial surface?
What about later when infarction is nearly complete?
more marked ST elevation
ST elevation, T wave inversion, and significant Q wave
What leads do you detect an anterior wall infarction?
What artery is this?
V3-V4
LAD
What leads do you detect an inferior wall infarction?
What artery is it?
II, III, AVF
RCA
What leads do you detect a lateral wall infarction?
What artery is it?
I, AVL, V5-V6
circumflex artery
What leads do you detect a posterior wall infarction?
What artery is it?
V1-V3
posterior descending artery
