Deck 2: Basic Electrophysiology

Question 1

Leads I,aVL,V5,and V6 view the _____ surface of the left ventricle.

A) anterior
B) septal
C) inferior
D) lateral

Answer 1

D
Leads I,aVL,V5,and V6 view the lateral surface of the left ventricle.

Question 2

In the heart's conduction system,the _____ receive(s)an electrical impulse from the bundle of His and relay(s)it to the Purkinje fibers in the ventricular myocardium.

A) atrioventricular (AV)node
B) atria
C) sinoatrial (SA)node
D) right and left bundle branches

Answer 2

D
The right and left bundle branches divide into smaller and smaller branches and then into a special network of fibers called the Purkinje fibers.These fibers spread from the interventricular septum into the papillary muscles.They continue downward to the apex of the heart,composing an elaborate web that penetrates about one third of the way into the ventricular muscle mass.The fibers then become continuous with the muscle cells of the right and left ventricles.

Question 3

In most ECG leads,a normal Q wave is less than 0.04 seconds in duration and less than one third the amplitude of the R wave in that lead.

Answer 3

True
With the exception of leads III and aVR,a normal Q wave in the limb leads is less than 0.04 seconds (one small box)in duration and less than one third the height of the R wave in that lead.An abnormal (pathologic)Q wave is more than 0.04 seconds in duration or more than one third the height of the following R wave in that lead.Myocardial infarction is one possible cause of abnormal Q waves.

Question 4

Depolarization is the same as contraction.

Question 5

_____ is the ability of cardiac pacemaker cells to spontaneously initiate an electrical impulse without being stimulated from another source,such as a nerve.

A) Excitability
B) Conductivity
C) Automaticity
D) Contractility

Question 6

The period of time during the cardiac cycle when cells cannot respond to a stimulus,no matter how strong,is the relative refractory period.

Question 7

How do you determine whether the atrial rhythm on an ECG tracing is regular or irregular?

A) Compare QT intervals.
B) Compare PR intervals.
C) Compare R to R intervals.
D) Compare P to P intervals.

Question 8

If the wave of depolarization (electrical impulse)moves toward the positive electrode,the waveform recorded on ECG graph paper will be upright (positive deflection).

Question 9

Leads II,III,and aVF view the _____ surface of the left ventricle.

A) anterior
B) inferior
C) septal
D) lateral

Question 10

In the heart's conduction system,the _____ receive(s)an electrical impulse from the right and left bundle branches and relay(s)it to the ventricular myocardium.

A) AV node
B) SA node
C) Purkinje fibers
D) atrial pacemaker cells

Question 11

The point where the QRS complex and the ST segment meet is called the ST junction or J-point.

Question 12

In most patients,the sinoatrial (SA)and atrioventricular (AV)nodes are supplied by the _____ coronary artery.

A) right
B) left main
C) circumflex
D) left anterior descending

Question 13

Lead II records the difference in electrical potential between the _____ leg and _____ arm.

A) left; left
B) left; right
C) right; left
D) right; right

Question 14

In the limb leads,the ST segment is normally isoelectric,or less than 1 mm above or below the isoelectric line.

Question 15

What does the QRS complex represent?

A) Atrial depolarization
B) Ventricular contraction
C) Ventricular repolarization
D) Ventricular depolarization

Question 16

The intrinsic rate of the atrioventricular (AV)bundle is _____ beats/min.

A) 20 to 40
B) 40 to 60
C) 60 to 80
D) 80 to 100

Question 17

The period during the cardiac cycle when cells cannot respond to a stimulus,no matter how strong,is called the _____ period.

A) depolarized
B) supranormal
C) relative refractory
D) absolute refractory

Question 18

On an ECG,what is the first negative deflection seen after the P wave?

A) Q wave
B) R wave
C) S wave
D) T wave

Question 19

A conduction problem above the level of the bundle branches will largely affect the P wave and PR interval.

Question 20

The normal pacemaker of the heart is the _____ node,which is found in the _____ atrium,and has an intrinsic firing rate of _____ beats/min.

A) sinoatrial; left; 40 to 60
B) sinoatrial; right; 60 to 100
C) atrioventricular; left; 20 to 40
D) atrioventricular; right; 100 to 180

Question 21

The appearance of coved ("frowny face")ST-segment elevation is called a(n)_____ _____ _____.

Question 22

On the ECG,the T wave represents _____.

A) atrial contraction
B) atrial repolarization
C) ventricular contraction
D) ventricular repolarization

Question 23

In an adult,the normal duration of the QRS complex is _____.

A) 0.12 to 0.20 seconds
B) 0.10 seconds or less
C) 0.04 to 0.14 seconds
D) 0.20 seconds or less

Question 24

On the ECG,the P wave represents atrial _____ and the QRS complex represents ventricular _____.

A) depolarization; depolarization
B) repolarization; repolarization
C) repolarization; depolarization
D) depolarization; repolarization

Question 25

When the cardiac muscle cell is stimulated,the cell is said to _____.

A) polarize
B) recover
C) depolarize
D) repolarize

Question 26

Tall,peaked T waves observed on the ECG are most commonly seen in patients with _____.

A) hypokalemia
B) hyperkalemia
C) hyponatremia
D) hypernatremia

Question 27

The portion of the ECG tracing between the QRS complex and the T wave is called the ____.

A) PR segment
B) ST segment
C) TP segment
D) QT interval

Question 28

The absolute refractory period begins with the onset of the _____ and terminates _____.

A) P wave; with the end of the QRS complex
B) QRS complex; at approximately the apex of the T wave
C) QRS complex; with the end of the T wave
D) P wave; with the beginning of the QRS complex

Question 29

The intrinsic rate of the SA node is _____ beats/min.

A) 40 to 60
B) 60 to 100
C) 100 to 180
D) 200 to 260

Question 30

_____ cells are working cells of the heart that contain contractile filaments and form the muscular layer of the atrial walls and the thicker muscular layer of the ventricular walls.

A) Pacemaker
B) Myocardial
C) Specialized
D) Electrical

Question 31

_____ is a term used to describe the period of recovery that cells need after being discharged before they are able to respond to a stimulus.

A) Irritability
B) Conductivity
C) Polarization
D) Refractoriness

Question 32

Which of the following is the first positive deflection seen on the ECG after the P wave?

A) Q wave
B) R wave
C) S wave
D) T wave

Question 33

The PR interval is considered prolonged if it is more than _____ seconds in duration.

A) 0.06
B) 0.12
C) 0.18
D) 0.20

Question 34

The QT interval is measured from the beginning of the _____.

A) QRS complex to the end of the T wave
B) P wave to the end of the QRS complex
C) QRS complex to the beginning of the T wave
D) P wave to the beginning of the QRS complex

Question 35

An ECG lead that has a positive and negative electrode is called a(n)_____ lead.

Question 36

_____ is the ability of cardiac cells to spontaneously initiate an electrical impulse without being stimulated from another source.

Question 37

Which of the following correctly reflects examples of ectopic (latent)pacemakers?

A) The SA node and AV junction
B) The AV junction and ventricles
C) The SA node and right bundle branch
D) The AV junction and left bundle branch

Question 38

On the ECG,the time necessary for the spread of an electrical impulse through the AV node,bundle of His,right and left bundle branches,and the Purkinje fibers is reflected by the _____.

A) TP segment
B) PR segment
C) QT interval
D) QRS duration

Question 39

Which part of the conduction system receives an impulse from the bundle of His and relays it to the Purkinje fibers?

A) SA node
B) AV node
C) Right and left atria
D) Right and left bundle branches

Question 40

The intrinsic rate of the Purkinje fibers is _____ beats/min.

A) 20 to 40
B) 40 to 60
C) 60 to 100
D) 100 to 180

Question 41

MATCHING
a.Electrolyte
b.Voltmeter
c.Chemical
d.Ectopic
e.Reciprocal changes
f.Atrial
g.Indicative changes
h.Amplitude
i.Repolarization
j.Supranormal
k.Ventricular
l.Reentry
m.Positive
n.Augmented
Element or compound that breaks into charged particles (ions)when melted or dissolved in water or another solvent

Question 42

MATCHING
a.Electrolyte
b.Voltmeter
c.Chemical
d.Ectopic
e.Reciprocal changes
f.Atrial
g.Indicative changes
h.Amplitude
i.Repolarization
j.Supranormal
k.Ventricular
l.Reentry
m.Positive
n.Augmented
The T wave represents ventricular _____.

Question 43

MATCHING
a.Electrolyte
b.Voltmeter
c.Chemical
d.Ectopic
e.Reciprocal changes
f.Atrial
g.Indicative changes
h.Amplitude
i.Repolarization
j.Supranormal
k.Ventricular
l.Reentry
m.Positive
n.Augmented
The spread of an impulse through tissue already stimulated by that same impulse

Question 44

MATCHING
a.Electrolyte
b.Voltmeter
c.Chemical
d.Ectopic
e.Reciprocal changes
f.Atrial
g.Indicative changes
h.Amplitude
i.Repolarization
j.Supranormal
k.Ventricular
l.Reentry
m.Positive
n.Augmented
During this period,a weaker than normal stimulus can cause depolarization of cardiac cells.

Question 45

MATCHING
a.Electrolyte
b.Voltmeter
c.Chemical
d.Ectopic
e.Reciprocal changes
f.Atrial
g.Indicative changes
h.Amplitude
i.Repolarization
j.Supranormal
k.Ventricular
l.Reentry
m.Positive
n.Augmented
ECG changes observed in leads opposite the affected area of the heart; also called mirror image changes

Question 46

MATCHING
a.Electrolyte
b.Voltmeter
c.Chemical
d.Ectopic
e.Reciprocal changes
f.Atrial
g.Indicative changes
h.Amplitude
i.Repolarization
j.Supranormal
k.Ventricular
l.Reentry
m.Positive
n.Augmented
Height (voltage)of a waveform on the ECG

Question 47

MATCHING
a.Electrolyte
b.Voltmeter
c.Chemical
d.Ectopic
e.Reciprocal changes
f.Atrial
g.Indicative changes
h.Amplitude
i.Repolarization
j.Supranormal
k.Ventricular
l.Reentry
m.Positive
n.Augmented
The a in aVR,aVL,and aVF

Question 48

The cells of the heart that contain contractile filaments are called _____ cells.

Question 49

MATCHING
a.Electrolyte
b.Voltmeter
c.Chemical
d.Ectopic
e.Reciprocal changes
f.Atrial
g.Indicative changes
h.Amplitude
i.Repolarization
j.Supranormal
k.Ventricular
l.Reentry
m.Positive
n.Augmented
An ECG machine is a sophisticated _____.

Question 50

On the ECG,what do the ST segment and T wave represent?

Question 51

Name the first positive deflection seen after the P wave on the ECG.

Question 52

Explain the significance of Einthoven's triangle.

Question 53

MATCHING
a.Electrolyte
b.Voltmeter
c.Chemical
d.Ectopic
e.Reciprocal changes
f.Atrial
g.Indicative changes
h.Amplitude
i.Repolarization
j.Supranormal
k.Ventricular
l.Reentry
m.Positive
n.Augmented
The stimulus that alters the electrical charges across the cell membrane may be electrical,mechanical,or _____.

Question 54

MATCHING
a.Electrolyte
b.Voltmeter
c.Chemical
d.Ectopic
e.Reciprocal changes
f.Atrial
g.Indicative changes
h.Amplitude
i.Repolarization
j.Supranormal
k.Ventricular
l.Reentry
m.Positive
n.Augmented
The QRS complex represents _____ depolarization.

Question 55

MATCHING
a.Electrolyte
b.Voltmeter
c.Chemical
d.Ectopic
e.Reciprocal changes
f.Atrial
g.Indicative changes
h.Amplitude
i.Repolarization
j.Supranormal
k.Ventricular
l.Reentry
m.Positive
n.Augmented
The P wave represents _____ depolarization.

Question 56

Complete the following chart:

Question 57

MATCHING
a.Electrolyte
b.Voltmeter
c.Chemical
d.Ectopic
e.Reciprocal changes
f.Atrial
g.Indicative changes
h.Amplitude
i.Repolarization
j.Supranormal
k.Ventricular
l.Reentry
m.Positive
n.Augmented
ECG changes observed in leads that look directly at the affected area of the heart

Question 58

MATCHING
a.Electrolyte
b.Voltmeter
c.Chemical
d.Ectopic
e.Reciprocal changes
f.Atrial
g.Indicative changes
h.Amplitude
i.Repolarization
j.Supranormal
k.Ventricular
l.Reentry
m.Positive
n.Augmented
Impulse(s)originating from a source other than the SA node

Question 59

A line between waveforms is called a(n)_____.

Question 60

MATCHING
a.Electrolyte
b.Voltmeter
c.Chemical
d.Ectopic
e.Reciprocal changes
f.Atrial
g.Indicative changes
h.Amplitude
i.Repolarization
j.Supranormal
k.Ventricular
l.Reentry
m.Positive
n.Augmented
Each electrode placed in a "V" position is a(n)_____ electrode.

Question 61

Complete the following chart:

Question 62

Generally speaking,what is the normal duration of a QT interval?

Question 63

List four major electrolytes that influence cardiac function.

Question 64

List three causes of artifact on an ECG tracing.

Question 65

List the ECG leads that view the heart in the horizontal plane,allowing a view of the front and left side of the heart.

Question 66

Is depolarization the same as contraction? Explain your answer.