ECG Basics (lec 2) Flashcards
(29 cards)
Small square shows?
0.04 sec and 0.1 mV
5 small squares?
= one large box
0.20 sec
Horizontal measurements determine?
heart rate
Isoelectric Line is?
flat line
no or very weak activity
use as baseline for Δ in electrical movement
P Wave produced by?
Duration?
initiation of SA node impulse,
depol of R and L atria,
impulse thru AV jxn
0.06 - 0.10 sec
PR Interval?
Duration?
start of P to start of QRS
0.12 - 0.20 sec
PR Segment?
flat line b/w end of P wave and start of QRS complex
QRS Complex?
Duration?
follows PR segment
Q = 1st neg deflection post PR seg
R = 1st + defl post Q or PR seg
S = 1st neg defl below baseline, post R
0.06 - 0.11 sec
ST Segment?
flat line post QRS complex
T Wave?
larger, asym wave post ST seg
J-Point?
where QRS complex meets ST seg
QT Interval from where to where?
Represents what?
Duration?
distance from onset of QRS Complex to end of T Wave
time of vent depol/repol
0.36 - 0.44 sec
Typical ECG rhythm?
slide 12
Artifact is?
marking not produced by heart
e.g. pt moves
Bipolar Leads record?
Which leads are bipolar?
difference in elect potential b/w electrodes
I, II, III
Lead I?
Standard Limb Lead
R wrist -> L wrist
RA neg, LA +
Lead II?
Standard Limb Lead
R wrist -> L ankle
RA neg, LL +
Lead III?
Standard Limb Lead
L wrist -> L ankle
LA neg, LL +
Unipolar Leads?
Which leads are unipolar?
use one + electrode and reference point in center of heart
Augmented limb leads, Precordial leads
Augmented Limb Leads?
use same leads as limb but only one +,
other two are grounds
aVR?
R wrist
RA +
views heart base (atria, great vessels)
aVL?
L wrist
LA +
views lateral wall of LV
aVF?
L ankle
LL +
views inferior wall of LV
Chest Leads?
precordial (horizontal plane)
all +
