ECGs Flashcards
what does height and width indicate
height: voltage
width: time
what is height and width of 1 small box
H: 0.1mV
W: 40ms
what is height and width of large box
H 0.5mV
W: 200ms
what does pulse at beginning mean
1mV
how long is a full strip
10s
2 ways to figure out HR
- count all and x6
2. 300/# of squares between beats
what does pos vs neg wave mean
direction of wave
what is key to measure of whether pos or neg
area under the curve
which leads measure coronal vs. transvers
coronal: limb leads
transverse: precordial
where are leads 1,2,3
1 - left arm 0deg
2 - left leg +60
3 - right arm +120
where are aVL, aVF, aVR
aVL: -30
aVF: +90
aVR: -150
which 2 pairs are perpendicular
- 1 and aVF
2. 2 and aVL
where do precordial leads go
V1 and V2: either side of sternum
V4: midclavicular
V6: mid axillary
what do V1 and V2 measure
septum
what do V3 and V4 measure
L vent
what measures lateral wall
1, aVL, V5, V6
what measures inferior wall
2, 3, aVF
where is normal vent. polarization from
1 and 2
where is normal QRS axis
-30 to +90
where is left axis deviation (LAD)
-90- -30
where is RAD
+180 - +90
what do P R T wave represent
P - atrium
R - ventricles
T - reporlarization
what is normal P wave amplitude and duration
amp: <0.25mv (2.5 small boxes)
dur: 40-120 (1-3 small boxes)
what is PR interval and what does it represent
start of P to start of R
- time through atria and AV node
