EKG

Question 1

the contractile machinery of the heart

Answer 1

myocardial cells

Question 2

Types of heart cells: (3)

Answer 2

• pacemaker cells
• electrical conducting cells
• myocardial cells

Question 3

Pacemaker cells depolarize spontaneously. True or false?

Answer 3

true

Question 4

Myocytes are depolarized at rest. True or false?

Answer 4

false, they are polarized

Question 5

The rate of depolarization of the pacemaker cells is determined by: (2)

Answer 5

innate electrical characteristic

external neural & hormonal input

Question 6

Each depolarization serves as a source of a wave of depolarization that initiates one complete cycle of cardiac contraction and relaxation. True or false?

Answer 6

true

Question 7

A record of one electrical cycle of depolarization and repolarization of a single cell is:

Answer 7

action potential

Question 8

When there is depolarization, the heart _____.

Answer 8

contracts

Question 9

The dominant pacemaker of the heart is the ____ ____.

Rate is:

Answer 9

sinus node

60-100 bpm

Question 10

The rate of the sinus node can be altered by the autonomic nervous system, like the vagus response. True or false?

Answer 10

true

Question 11

All heart cells possess this ability to behave as a pacemaker. This is suppressed unless SA node fails.

Answer 11

automaticity

Question 12

AV node fires at ____ - _____ BPM

Answer 12

40–60

Question 13

Bundle of His fires at ___ - ____ BPM

Answer 13

30-40

Question 14

Purkinje fibers fire at a rate of ___ - ___ BPM

Answer 14

20-30

Question 15

The ventricular conducting system has been precisely defined. True or false?

Answer 15

true

Question 16

The atrial conducting system has been precisely defined. True or false?

Answer 16

false, still debated

Question 17

The amplitude of a wave is measured in:

Answer 17

millivolts

Question 18

Each small box is 1mm and equals ____ sec

Answer 18

0.04

Question 19

Each large square is ___ mm and equal to ___ sec

Answer 19

5

0.2 sec

Question 20

Vertical axis on ECG is ______.

Small square = ______

Large square = _____.

Answer 20

voltage

0. 1 mV
1. 5 mV

Question 21

recording of depolarization through the atrial myocardium

Answer 21

P wave

Question 22

The AV node delays conduction from the atria to the ventricles to allow the atria to finish contracting before the ventricles begin to contract. True or false?

Answer 22

true

Question 23

___ wave represents the wave of ventricular repolarization

Answer 23

t wave

Question 24

The wave of atrial repolarization is obscured by the QRS complex. True or false?

Answer 24

true

Question 25

Measures time from start of atrial depolarization to start of ventricular depolarization

Answer 25

PR interval

Question 26

Measures from the end of ventricular depolarization to the start of ventricular repolarization

Answer 26

ST segment

Question 27

Measures time from beginning of ventricular depolarization to the end of ventricular repolarization.

Answer 27

QT interval

Question 28

A wave of depolarization towards a positive electrode - ____ deflection

Answer 28

positive

Question 29

A wave of depolarization away from a positive electrode = _____ deflection

Answer 29

negative

Question 30

A depolarizing wave moving perpendicular to a positive electrode = _____ wave

Answer 30

biphasic

Question 31

A wave of repolarization moving toward a positive electrode gives a _______ deflection.

Answer 31

negative

Question 32

A wave of repolarization moving away from a positve electrode gives a ______ deflection.

Answer 32

positive

Question 33

Lead I is with left arm (\_\_\_) and right arm (\_\_\_\_)

Answer 33

+ -

Question 34

Lead II is with the legs (\_\_\_\_) and the right arm (\_\_\_)

Answer 34

+ -

Question 35

Lead III is with the _____ (+) and the ____ (-).

Answer 35

legs left arm

Question 36

Three augmented leads are: (3) \_\_\_\_ is with the left arm (+) and other limbs (-) \_\_\_\_\_\_ is with right arm (+) and other limbs (-) \_\_\_\_\_ is with legs (+) and arms (-)

Answer 36

AVL AVR AVF

Question 37

Which lead is placed midclavicular?

Answer 37

V4

Question 38

Which lead is in the 5th intercostal space on the anterior axillary line?

Answer 38

V5

Question 39

What lead is 5th intercostal, midaxillary line?

Answer 39

V6

Question 40

Which lead is in the 4th intercostal space on the right side of the sternum?

Answer 40

V1

Question 41

Which lead is on the 4th intercostal space on the left side of the sternum?

Answer 41

V2

Question 42

Region of the heart affected by Leads II, III, AVF:

Answer 42

inferior

Question 43

Region of the heart affected by V1, V2, V3, V4:

Answer 43

anterior

Question 44

Region of the heart affected by AVR:

Answer 44

none

Question 45

Region of the heart affected by I, AVL, V5, V6:

Answer 45

left lateral

Question 46

If viewing in the frontal plane, Lead I and AVL toward current will give ____ wave

Answer 46

positive

Question 47

If looking in frontal plane at lead III, perpendicular to the current = _____ p wave

Answer 47

biphasic

Question 48

If looking in the frontal plane at lead AVR: away from the current = _____ p wave

Answer 48

negative

Question 49

P wave amplitude is most positive in lead ___ and most negative in \_\_\_\_

Answer 49

II AVR

Question 50

The PR interval lasts ___ - ____ sec

Answer 50

0.12 - 0.2 sec PR interval represents the time from the start of atrial depolarization to the start of ventricular depolarization

Question 51

What represents depolarization of the interventricular septum? It is a tiny negative deflection in the left lateral leads I, AVL, V5, and V6

Answer 51

septal Q waves

Question 52

If you have pronounced Q waves, can indicate ______ \_\_\_\_\_

Answer 52

myocardial infarction

Question 53

Which lead has the smallest R wave?

Answer 53

V1

Question 54

Which lead has the largest R wave?

Answer 54

V5

Question 55

QRS lasts ___ to ___ sec

Answer 55

0.06 - 0.1 sec

Question 56

Represents the time from the end of ventricular depolarization to the start of ventricular repolarization. Elevation or depression by \> _____ is significant and indicates a problem

Answer 56

ST segment 1 mm

Question 57

Represents ventricular repolarization

Answer 57

t wave

Question 58

cardiac cells are

Answer 58

myocytes