Lecture 7- MI

Question 1

sub-epicardial

Answer 1

entire thickness of cardiac wall is affected

Question 2

sub-endocardial

Answer 2

partial thickness of cardiac wall is affected

Question 3

ventricular remodeling

Answer 3

after MI
both infarcted and non-infarcted areas
changes in shape and thickness

Question 4

is ischemia reversible?

Answer 4

yes

Question 5

if EDV is higher, therefore

Answer 5

stroke volume is lower

Question 6

sympathetic activation during MI (4)

Answer 6

increase HR and BP
constrict arterioles
venoconstriction
increased RAA

Question 7

compensatory mechanisms during MI (3)

Answer 7

aren’t actually helping

sympathetic NS
hypertrophy
vasovagal response

Question 8

vasovagal response

Answer 8

leads to bradycardia and hypertension

Question 9

symptoms during MI

Answer 9

chest discomfort
nausea
dyspnea (difficulty breathing)
diaphoresis (sweating)
weak 
hypertension 
arrhythmia

Question 10

biomarkers in MI

Answer 10

myoglobin
CK-MB
Trop 1
Trop 2
CK
LDH

Question 11

which biomarkers will remain elevated

Answer 11

trop 1 and 2 (best markers)

Question 12

area of necrosis

Answer 12

tissue is dead

Question 13

what causes changes in T wave?

Answer 13

ischemia prolongs repolarization

inversion or tall T wave- early sign

Question 14

3 I’s

Answer 14

ischemia
injury
infarct

Question 15

ischemia

Answer 15

T wave inversion or tall T

Question 16

injury

Answer 16

ST elevation- subepicardial injury

ST depression- subendocardial injury

Question 17

infarct

Answer 17

abnormal Q wave

Question 18

J point

Answer 18

where ST segment begins
above baseline- elevation
below baseline- depression

Question 19

smiley

Answer 19

in healthy pt, benign

Question 20

frowny

Answer 20

myocardial damage

Question 21

EKG changes during MI

Answer 21

onset of pain, normal EKG w/ tall T wave
1 hr- ST elevation means myocardial necrosis
if given drugs- ST reduces by 50%
24 hrs- ST returning to normal, T wave inverted
months- deep Q wave

Question 22

what do leads II, III, aVF see?

Answer 22

RCA, inferior surface

Question 23

what do leads V5, V6, I, aVL see?

Answer 23

LCX, lateral surface

Question 24

what do leads V3, V4 see?

Answer 24

LAD, anterior surface

Question 25

what do leads V1, V2 see?

Answer 25

LCA, septal

Question 26

treatment for MI

Answer 26

reduce O2 demand, increase blood flow

how- O2, rest, beta blockers, calcium channel blockers

Question 27

grafts used for bypass

Answer 27

internal mammary artery
radial artery
saphenous vein (most common)
gastroepipolic artery