EKG I

Question 1

Myocytes

Answer 1

cardiac cells, electrically polarized at rest

Question 2

Polarity

Answer 2

is maintaned by membrane pumps necessary to keep the inside of the cells electronegatave

Question 3

which pump maintains membrane electrical polarity

Answer 3

sodium/potassium

Question 4

Ratio of Na to K

Answer 4

3 Na outside for every 2 K inside

Question 5

What is needed to keep cell polarized

Answer 5

ATP

Question 6

pacemaker cells

Answer 6

electrical power source of the heart

Question 7

electrical conducting

Answer 7

the hard wiring of the heart

Question 8

myocardial cells

Answer 8

the contractile machinery of the heart

Question 9

what determines rate of depolarization

Answer 9

innate electrical characteristcs of the cell and the external neurohormonal input

Question 10

action potential

Answer 10

a record of one elecrical cycle of depolarization & repolarization from a single cell

Question 11

sinus node

Answer 11

dominant pacemaker of the heart, located in the RA, rate 60-100 BP, altered by Autonomic NS

Question 12

Automaticity

Answer 12

all hearts cells posses ability to behave as a pacemaker.

Question 13

intrinsic pacing SA node

Answer 13

60-100

Question 14

intrinsic pacing atrial foci

Answer 14

60-75

Question 15

junctional foci AV

Answer 15

40-60

Question 16

Ventricular foci (his bundle, etc.)

Answer 16

30-40

Question 17

horizontal small square distance in time

Answer 17

.04 sec

Question 18

horizontal large square distance in time

Answer 18

.2 sec

Question 19

vertical small square voltage

Answer 19

.1mV

Question 20

vertical large square voltage

Answer 20

.5mV

Question 21

P Wave

Answer 21

atrial depolarization

Question 22

3 parts of ventricular conduction

Answer 22

1-bundle of Hi, 2-Bundle Branches, 3-Terminal Purkinje fibers

Question 23

Q wave

Answer 23

1st downard deflection

Question 24

R wave

Answer 24

1st upward deflection

Question 25

R prime

Answer 25

a second upward upward deflection

Question 26

S wave

Answer 26

1st downard deflection following an R wave

Question 27

QS wave

Answer 27

entire configuration consits solely of one downward deflection

Question 28

Repolarization

Answer 28

restoration of electronegative state

Question 29

T wave

Answer 29

represents the wave ventricular repolarization

Question 30

PR Interval

Answer 30

from p wave to the start of QRS

Question 31

ST Segment

Answer 31

from the end of the QRS complex to the beginning of the T wave

Question 32

QT interval

Answer 32

includes the QRS complex, ST segment, and the T wave

Question 33

positive deflection

Answer 33

a wave of depolarization towards a positive electrode

Question 34

negative deflection

Answer 34

a wave of depolarization away from a positive electrode

Question 35

biphasic wave

Answer 35

a depolarizing wave moving perpendicular to a postive electrode

Question 36

deflections are reversed in repolarization

Answer 36

toward positive (negative deflection), perpendicular (negative precedes positive)

Question 37

lead I

Answer 37

right arm (-) left arm (+)

Question 38

lead II

Answer 38

right arm (-) legs (+)

Question 39

Lead III

Answer 39

left arm (-) legs (+)

Question 40

AVL

Answer 40

left arm (+) other limbs (-)

Question 41

AVR

Answer 41

right arm (+) other limbs (-)

Question 42

AVF

Answer 42

legs (+) arms (-)

Question 43

Anterior view of the heart

Answer 43

V2, V3, V4

Question 44

Left Lateral view of the heart

Answer 44

I, aVL, V5, V6

Question 45

Inferior view of the heart

Answer 45

II, III, aVF

Question 46

right ventricular

Answer 46

aVR, V1

Question 47

average movement

Answer 47

vector

Question 48

PR interval

Answer 48

0.12-0.2 sec

Question 49

Delay in AV node significance

Answer 49

allows ventricles to fill

Question 50

Q wave _mV

Answer 50

.1mV

Question 51

Q waves after inferior MI

Answer 51

strong negative Q wave.

Question 52

QRS average vector

Answer 52

0-90 degrees

Question 53

QRS Positive deflections

Answer 53

left lateral and inferior

Question 54

QRS duration

Answer 54

.06-1 sec

Question 55

> _mmhg in ST segment represents pathologic process

Answer 55

1mmhg

Question 56

QT represents _% of cardiac cycle

Answer 56

40 %