Cardiology 7.10 Flashcards
draw out bipolar leads I, II, III
pg 122
dipole is most parallel to what lead
II
dipole is always pointing towards
resting tissue
mean dipole is referring to
average height of QRS complex
if mean dipole is oriented towards positive side
max positive signal
if mean dipole is oriented toward negative side get
max negative signal
orientation of dipole in regards to electrodes tell you fif signal is going
up or down
when dipole is perpendicular to electrodes
isoelectric
for every lead there is a 180 degree sweep
where it can be positive or negative
draw out where chest leads are placed
pg 123
precordial leads mean
chest leads
if dipole is approaching positive electrode what kind of signal
positive
what are the augmented unipolar limb leads
aVR
aVL
aVF
drraw out aVR
pg 124
draw out aVL
pg 124
draw out aVF
pg 124
large box is what timing
200 msec/large box
what is the timing of small box
40 msec/small box
how do you determine HR
either divide by 300
or memorize 300, 150, 100, 75, 60, 50, 43
1 box RR interval is what HR
300
list out the HR for R-R interval 107
pg 126
what is P interval
beginning of P to beginning of Q
QRS is determine what
signal propegates through ventricles
if there is bundle branch block what happens to ventricles
decreases
QT duration is good index of
overall AP duration
loss of potassium channel what happens to AP
long AP duration
QT interval is sensitive to
HR
PR interval major part is due to propagation through
AV node
what is displayed at bottom of ECG
rhythm strip
what does rhythm strip show
regularity of beating
first degree heart block
abnormally long conduction velocity through AV node
if you were to draw what average dipole is as it moves through atria
the red line pointing on pg 133 circled in pink
review normal activation sequence and how dipole affects ECG
pg 133
because epicardial cells have shorter AP duration they will
replarize first
during ischemia it’s not uncommon for endocardial surface to become ischemiac beofre
epicardial
if endocardial surface repol faster than epicardial what happens to dipole
it will switch around and T wave will be negative
review pg 137
pg 137
mean axis oriented most ___ to the lead with largest net amplitude
parallel
if AVF is isoeletric what does angle have to be pg 140
0 or 180
review pg 140
140
pg 141 there is question!
141
if QRS is mainly positive leads I and II then main axis is between
+90 and -30 and is normal
less than 60 beats per min is
bradycardia
more than 100 beats for min is
tachycardia
