lecture 1 (chapter 1, 2, 4 and 7)

Question 1

beat of the heart is due to a rhythm discharge of ____ stimuli

Answer 1

electrical

Question 2

the information recorded on the EKG represents the hearts _____ activity

Answer 2

electrical

Question 3

most of the information on the EKG represents electrical activity of _____ of the myocardium

Answer 3

contraction

Question 4

while in the resting state, myocytes are polarized, the interior of every cell being ______-ly charged

Answer 4

negatively

Question 5

the interiors of resting myocytes are negative, but when these cells are depolarized, their interiors become ____ and the cells contract

Answer 5

positive

Question 6

myocardial contraction is caused by_______ of the mycoytes

Answer 6

depolarization

Question 7

a wave of depolarization advancing through the myocardium is a moving wave of _____ charges

Answer 7

positive

Question 8

what is the heart’s predominant pacemaker

Answer 8

SA node

Question 9

the ability of the SA node to generate pacemaking stimuli is known as _____

Answer 9

automaticity

Question 10

atrial depolarization is recorded as a ____ wave on EKG

Answer 10

P

Question 11

depolarization of the ventricular myocytes produces a ____ complex on the EKG and initiates contraction of the ventricles

Answer 11

QRS

Question 12

the QT interval represents the duration of ventricular ____ and is measured from the beginning of the QRS until the end of the T wave

Answer 12

systole

Question 13

when is the QT interval considered normal

Answer 13

when it is less than half of the R-to-R interval at normal rates

Question 14

the release of free Ca++ ions into the interiors of the myocytes produces myocardial

Answer 14

contraction

Question 15

following depolarization, repolarization is due to the controlled outflow of ____ ions from the myocytes

Answer 15

K+

Question 16

the amount of time represented by the distance between 2 heavy black lines is ____

Answer 16

0.2 of a second

Question 17

each small division (measured horizontally between 2 fine lines) represents ____

Answer 17

0.04 of a second

Question 18

what leads are considered lateral leads

Answer 18

leads I and IVL

Question 19

what leads are considered inferior leads

Answer 19

II, III, and AVF

Question 20

if leads V1 through V6 are imagined to be spokes of a wheel, the center of the wheel is the ____

Answer 20

AV node

Question 21

lead V2 describes a straight line directly from the front to the back of the patient. In the lead V2 the patients back is considered ____

Answer 21

negative

Question 22

when examine an EKG, you should determine the ____ first

Answer 22

rate

Question 23

what do ventricular automaticity foci all pace within the range of

Answer 23

20-40 per minute range

Question 24

what is the only conduction like between the aura and the ventricular conduction system below

Answer 24

AV node

Question 25

define arrrhythmia

Answer 25

without rhythm

Question 26

axis refers to the _____of depolarization as it passes through the heart

Answer 26

direction

Question 27

there is increased depolarization in a ____ ventricle

Answer 27

hypertrophied

Question 28

if the mean QRS vector points toward the right, we expect the QRS complex in lead I to be ____

Answer 28

negative

Question 29

if the QRS in lead I is upright, the vector points to the patient's

Answer 29

left

Question 30

the chest leads form the _____ plane

Answer 30

horizontal

Question 31

the chest electrode used for recording lead V2 is always _____

Answer 31

positive

Question 32

a wave of depolarization traveling towards a positive EKG electrode causes a/an ____ deflection of the EKG tracing

Answer 32

upward/positive

Question 33

a wave of depolarization traveling away from a positive EKG electrode causes a/an _____ deflection on the EKG tracing

Answer 33

negative/downward

Question 34

describe the PR interval

Answer 34

distance (time) from beginning of P wave to beginning of QRS complex

Question 35

describe the QT interval

Answer 35

distance (time) from beginning of QRS complex to end of T wave

Question 36

describe the ST interval

Answer 36

distance (time) from end of QRS complex to end of T wave

Question 37

what phase is the ST segment

Answer 37

plateau phase

Question 38

what is the most widely accepted cause for the U wave

Answer 38

depolarization of the purkinje fibers

Question 39

what does the vertical axis of the tracing represent

Answer 39

voltage

Question 40

what does 1mm equal at standard calibration of the vertical axis

Answer 40

0.1 mV

Question 41

what does the horizontal axis of the tracing represent

Answer 41

time

Question 42

what does 1 mm at standard paper speed on the horizontal axis represent

Answer 42

0.04 sec/ 40 msec

Question 43

how many big blocks are there per second

Answer 43

5

Question 44

how many big blocks are there per minute

Answer 44

300

Question 45

what plane are the precordial leads in

Answer 45

horizontal

Question 46

describe the 3 bipolar limb leads

Answer 46

each has 1 positive and 1 negative electrode

Question 47

describe the 3 augmented unipolar limb leads

Answer 47

each has 1 positive electrode and 1 compound reference electrode

Question 48

describe lead 1 and AVF with normal EKG (rotation)

Answer 48

both are upward

Question 49

describe lead 1 and AVF with R.A.D.

Answer 49

lead 1 is downward; AVF is upward

Question 50

describe lead 1 and AVF with extreme R.A.D.

Answer 50

lead 1 and AVF are both downward

Question 51

describe lead 1 and AVF with L.A.D

Answer 51

lead 1 is upward and AVF is downward

Question 52

what is the normal angle for AVL

Answer 52

-30

Question 53

what is the normal angle for lead 1

Answer 53

0

Question 54

what is the normal angle for AVR

Answer 54

+30

Question 55

what is the normal angle for lead II

Answer 55

+60

Question 56

what is the normal angle for AVF

Answer 56

+90

Question 57

what is the normal angle for lead III

Answer 57

+120

Question 58

how is the rotation described if the ratio of the R:S ratio changes from <1 to >1 after V4 (horizontal plane)

Answer 58

leftward axis rotation

Question 59

how is the rotation described if the ratio of the R:S ratio changes from <1 to >1 at or before V2 (horizontal plane)

Answer 59

rightward axis rotation

Question 60

how is the rotation described if the ratio of the R:S ratio changes from <1 to >1 after V2 and at or before V4 (horizontal plane)

Answer 60

normal

Question 61

what happens if in the horizontal plane the R:S ratio starts <1 and stays <1

Answer 61

leftward axis rotation

Question 62

what happens if in the horizontal plane the R:S ratio starts >1 and stays >1

Answer 62

rightward axis rotation

Question 63

what happens if in the horizontal plane the R:S ratio starts >1 and becomes <1 by V6

Answer 63

leftward axis rotation