ECG Basics (lec 2)

Question 1

Small square shows?

Answer 1

0.04 sec and 0.1 mV

Question 2

5 small squares?

Answer 2

= one large box

0.20 sec

Question 3

Horizontal measurements determine?

Answer 3

heart rate

Question 4

Isoelectric Line is?

Answer 4

flat line
no or very weak activity
use as baseline for Δ in electrical movement

Question 5

P Wave produced by?

Duration?

Answer 5

initiation of SA node impulse,
depol of R and L atria,
impulse thru AV jxn

0.06 - 0.10 sec

Question 6

PR Interval?

Duration?

Answer 6

start of P to start of QRS

0.12 - 0.20 sec

Question 7

PR Segment?

Answer 7

flat line b/w end of P wave and start of QRS complex

Question 8

QRS Complex?

Duration?

Answer 8

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

Question 9

ST Segment?

Answer 9

flat line post QRS complex

Question 10

T Wave?

Answer 10

larger, asym wave post ST seg

Question 11

J-Point?

Answer 11

where QRS complex meets ST seg

Question 12

QT Interval from where to where?

Represents what?

Duration?

Answer 12

distance from onset of QRS Complex to end of T Wave

time of vent depol/repol

0.36 - 0.44 sec

Question 13

Typical ECG rhythm?

Answer 13

slide 12

Question 14

Artifact is?

Answer 14

marking not produced by heart

e.g. pt moves

Question 15

Bipolar Leads record?

Which leads are bipolar?

Answer 15

difference in elect potential b/w electrodes

I, II, III

Question 16

Lead I?

Answer 16

Standard Limb Lead
R wrist -> L wrist
RA neg, LA +

Question 17

Lead II?

Answer 17

Standard Limb Lead
R wrist -> L ankle
RA neg, LL +

Question 18

Lead III?

Answer 18

Standard Limb Lead
L wrist -> L ankle
LA neg, LL +

Question 19

Unipolar Leads?

Which leads are unipolar?

Answer 19

use one + electrode and reference point in center of heart

Augmented limb leads, Precordial leads

Question 20

Augmented Limb Leads?

Answer 20

use same leads as limb but only one +,

other two are grounds

Question 21

aVR?

Answer 21

R wrist
RA +
views heart base (atria, great vessels)

Question 22

aVL?

Answer 22

L wrist
LA +
views lateral wall of LV

Question 23

aVF?

Answer 23

L ankle
LL +
views inferior wall of LV

Question 24

Chest Leads?

Answer 24

precordial (horizontal plane)

all +

Question 25

Chest Lead placement:

V1
V2
V3
V4
V5
V6

Answer 25

V1 = 4th ICS, R of sternum (RV)

V2 = 4th ICS, L of sternum (RV)

V3 = halfway b/w V2 and V4 (septum)

V4 = 5th ICS, MCL (septum)

V5 = anterior axillary line, same horizontal plane as V4

V6 = midaxillary line, same V4

Question 26

Precordial Leads view?

Include which leads?

Answer 26

view horizontal plane,
anterior and lateral views of heart

V1 - V6

Question 27

Modified Chest Leads provide?

Answer 27

continuous monitoring in ER, ICU, telemetry

Question 28

Modified Chest Leads placement?

Answer 28

same as V1 or V6

Question 29

Anterior Leads include?

Lateral Leads include?

Inferior Leads include?

Answer 29

V1-V4

I, aVL, V5-V6

II, III, aVF