ischemia and infarct Flashcards
the LAD supplies the
septum, bundle branches, and anterior and lateral left ventricle
anterolateral MI will involve
V4-V6
prolonged lack of O2 to the myocardium, beginning of cellular damage, no tissue necrosis
injury
MI involving V1-V3
anteroseptal
evolution of an acute MI
normal ECG >>> peaked (hyperacute) T wave >>> ST elevation + peaked T wave >>> pathologic Q wave + decrease in ST elevation + T wave inversion >>> just pathologic Q waves + T wave inversion >>> just pathologic Q waves + upright T waves
what causes symmetrical T wave inversion
the reversed direction of repolarization (becomes endo to epi) b/c the subepicardial layers take longer
____ T waves aka hyperacute T waves seen in the early stages of acute MI are ___ mm in limb leads and ___ mm in precordial leads
PEAKED T waves aka hyperacute T waves seen in the early stages of acute MI are MORE THAN 5 mm in limb leads and MORE THAN 10 mm in precordial leads
for subendocardial ischemia, there will be new onset angina and the ST segment will be ____
depressed
best leads for evaluating T wave changes
precordial
MI involving V2-V4
anterior
how do you differentiate T wave inversion due to strain vs ischemia
in strain, you will see R or L VH and the inverted T will be ASYMMETRICAL
the left circumflex artery supplies the
left atrium, lateral, and posterior aspects of the heart
symmetrical T wave inversion
transmural ischemia
Q wave without ST elevation or T wave abnormality
prior/ healed/ old infarction
MI involving V4-V6
anterolateral
anterior MI will involve
V2-V4
tall R waves with ST depression and reciprocal changes in V1-V2,
posterior MI caused by occlusion of the right coronary artery
Q wave/ ST segment/ T wave changes in V1-V3 with reciprocal changes in the inferior leads
anteroseptal MI caused by occlusion of the LAD
___ receptor stimulation of the coronary arteries causes vasoconstriction
alpha
for transmural ischemia, there will be variable angina and the ST segment will be ____
elevated
___ artery divides into the ___ and the ___ branches whihc supply the LA, LV, and septum
LEFT MAIN CORONARY ARTERY artery divides into the LAD and the LEFT CIRCUMFLEX branches whihc supply the LA, LV, and septum
rapidly upsloping ST segments (in ST depression) represent
a smaller area of myocardium affected
at high HR, O2 demand is ____, but O2 delivery is ___
at high HR, O2 demand is HIGHEST, but O2 delivery is REDUCED (due to decreased diastole)
non Q wave infarction aka
subendocardial MI
Q wave/ ST segment/ T wave changes in V1-V2 with reciprocal changes in the inferior leads
septal MI caused by occlusion of the LAD
asymmetrical T wave inversion
RVH with strain
MI involving lead 1, aVL V5-V6
lateral
in an anterior STEMI (V1-V4), you would see reciprocal changes in
inferior leads (2, 3, aVF)
anteroseptal MI will involve
V1-V3