EKG Flashcards
normal PR interval
0.12-0.2 seconds
normal QT interval
0.4 - 0.43 seconds
p wave means
atrial depolarization
QRS complex means
ventricular depolarization, ventricular conduction
t wave means
ventricular repolarization
QT interval means
condition of ventricals
one small box horizontal
0.04 seconds
one large horizontal box
0.2 seconds
5 large boxes
1 second
normal QRS duration
0.06 - 0.12
R-R interval
0.6-1 second
HR calculation
count number of seconds between 2 R waves, divide 60/#
delay in conduction from SA to AV node
PR interval too long or short
when the AV node is the pacemaker, what will you see?
PR interval short, retrograde, hidden in QRS, or absent
bundle branch defect will show
wide QRS
delayed ventricular repolarization looks like
long QT
unipolar leads
V1-V6
limb leads
I, II, III, aVR, aVL, aVF
normal axis deviation
-30 to 90 degrees
QRS axis deviation
how to ensure proper lead placement
lead I positive, lead aVR negative
dextrocardia would be opposite
RCA location
inferior
CFX location
lateral
LAD location
anterior
inferior MI leads
II, III, aVF
lateral MI leads
I, aVL, V5, V6
anterior MI leads
V2, V3, V4
septal leads
V1, V2
inferolateral leads
II, III, aVF, V5, V6
anterolateral leads
V2, V3, V4, V5, V6
ischemia will show
t wave inversion
injury will show
ST elevation
infarction will show
Q wave (1/3 of R)
infarct is not old (weeks-months)
early - large, uniform, peaked T waves, then inverted T waves, then back to normal
significant ST depression/elevation
one small box/1mm in 2 leads of the same area
reciprocal changes
areas of ST depression opposite of ST elevation
helpful in diagnosing TRUE STEMI & ID high risk complications (poor outcomes)
common w inferior, anterior & lateral MIs
how to determine axis
lead II should be most positive
verify II positive, aVR, negative
EKG reading steps
1 verify lead placement
2 determine rate & rhythm
3 determine axis
4 r wave progression
5 look for signs of ischemia, injury, or infarct
