Part 1: EKG Basics

Question 1

myocardial cells exist in a…

Answer 1

polarized state

positive charge on OUTSIDE
negative charge on INSIDE

maintained by PUMPS

Question 2

how is the electrical signal transmitted through the heart

Answer 2

depolarization (more +)

it goes back to it’s steady state through repolarization–more negative

Question 3

Amplitude

Answer 3

heigh on the y axis

measured in millivolts

Question 4

.1 mV

Answer 4

one small box

Question 5

1 mV

Answer 5

two large boxes

Question 6

how does myocardial mass relate to amplitude

Answer 6

the GREATER the mass the BIGGER the amplitude it generates when it depolarizes

Question 7

width on the X axis

measured in SECONDS

Answer 7

Duration

Question 8

.04 s (40 ms)

Answer 8

small box

Question 9

.2 s (200 ms)

Answer 9

large box

Question 10

1 s (1000 ms)

Answer 10

5 large boxes

Question 11

demonstrate electric activity between electrodes

Answer 11

leads

Question 12

wave of depolarization moves TOWARDS the positive electrode

Answer 12

positive deflection (moves upward)

Question 13

give a good view through the inferior hear and lateral heart

Answer 13

limb leads

Question 14

II, III, aVF

Answer 14

inferior heart

since this is visible in the VERTICAL plane only the limb leads show it

Question 15

V1, V2, V3

Answer 15

anteiror heart (horizontal plane)

Question 16

V1, V2

Answer 16

inverted image of posterior heart

Question 17

I, aVL and V4 through V6

Answer 17

inverted image of the posterior heart

Question 18

I, aVL and V4-V6

Answer 18

LEFT side of the heart

Question 19

aVR and VI

Answer 19

RIGHT side of the heart