24. & 25. MI/ECGs Flashcards
(38 cards)
What does an EKG do
records electrical activity (depol) of heart from viewpoint of each ind lead
what plane do the limb leads show depol
frontal (coronal)
what leads show depol in the horizontal plane
precordial leads
what is the normal direction of depol
upper right to lower left (RA to LV)
a positive deflecion on the QRS is ____
toward the lead
a negative deflection is ____ from the lead
away
QRS lead 1 (+) & avF (-) mean–
left axis deviation
what problems can lead to left axis deviations
ascities ( move herat & diaphragm up)
large belly
LV hypertrophy
QRS lead 1 = (-) & avF = (+)
right axis deviation
lung dieases show what kind of deviation
right axis deviation
what are symptoms associated with MIs
nausea, vomiting, diaphoresis, dyspnea
chest discomfort: heavy, pressure crushing
retrosternal, L, across chest, radiate into neck, jaw, L arm/shoulder, epigastrium or btn shoulder blades
what could be present with partial occlusion
unstable angina
NSTEMI
if coronary flow is occluded, pt presents w/
STEMI
what is the most likely cause of MI
atherosclerosis
If there is ischemia - you’ll see –
T wave changes - inverted, tall peak or depressed
-deficient blood supply & impaired repol
myocardial injury is seen by
ST segment shifts
deficient blood supply & inability to fully polarize
infarctions are seen w/ —
changes in Q waves (wide)
dead tissue, lack depol
when is tropinin I & T detectable during a MI
1-4 hours after onset
-pears at 10-24 hr
what can cause false positive cTnT
renal failure
how much ST elevation shows STEMI
men - >= 2 mm at J poin in V2-3
women- >= 1.5 mm
what leads are supplies by the L circumflex A
avL
lead 1
V5-6
= lateral wall of heart
which leads are supplied by left anterior descending A
V1 - V4
= anterior wall of heart
which leads are supplied by the right coronary A
lead 2, 3
aVF
= inferior wall of heart
which leads are supplied by the posterior descending A
V1-3
= posterior wall of heart
