The ____ fascicle depolarizes the interventricular septum
Answer
septal
Card 11
____ fascicle runs along the anterior wall of the left ventricle
Answer
Anterior
Card 12
The ____ fascicle sweeps over the posterior wall of the left ventricle
Answer
posterior
Card 13
If the first deflection is downward, that part of the QRS complex is called a ____
Answer
Q wave
Card 14
The first upward deflection is called an ____
Answer
R wave
Card 15
If there is a second upward deflection, it is called ____
Answer
R′ (“R-prime”)
Card 16
The first downward deflection following an upward deflection is called an ____
Answer
S wave
Card 17
If the entire configuration consists solely of one downward deflection, the wave is called a ____
Answer
QS wave
Card 18
What is hidden?
Answer
See the picture.
Card 19
What is hidden?
Answer
See the picture.
Card 20
What is hidden?
Answer
See the picture.
Card 21
What is hidden?
Answer
See the picture.
Card 22
What is hidden?
Answer
See the picture.
Card 23
What is hidden?
Answer
See the picture.
Card 24
A wave of depolarization moving ____ a positive electrode causes a positive deflection on the EKG
Answer
toward
Therefore, a wave of depolarization moving away from a positive electrode causes a negative deflection.
Card 25
A wave of depolarization moving toward a positive electrode causes a ____ deflection on the EKG
Answer
positive
Therefore, a wave of depolarization moving away from a positive electrode causes a negative deflection.
Card 26
A depolarizing wave moving perpendicularly to a positive electrode creates a ____ wave
Answer
biphasic
Card 27
Lead ____ is created by making the left arm positive and the right arm negative. Its angle of orientation is 0°
Answer
I
Card 28
Lead I is created by making the left arm positive and the right arm negative. Its angle of orientation is ____°
Answer
0
Card 29
Lead ____ is created by making the legs positive and the right arm negative. Its angle of orientation is 60°
Answer
II
Card 30
Lead II is created by making the legs positive and the right arm negative. Its angle of orientation is ____°
Answer
60
Card 31
Lead ____ is created by making the legs positive and the left arm negative. Its angle of orientation is 120°
Answer
III
Card 32
Lead III is created by making the legs positive and the left arm negative. Its angle of orientation is ____°
Answer
120
Card 33
Lead ____ is created by making the left arm positive and the other limbs negative. Its angle of orientation is -30°
Answer
aVL
Card 34
Lead aVL is created by making the left arm positive and the other limbs negative. Its angle of orientation is ____°
Answer
-30
Card 35
Lead ____ is created by making the right arm positive and the other limbs negative. Its angle of orientation is -150°
Answer
aVR
Card 36
Lead aVR is created by making the right arm positive and the other limbs negative. Its angle of orientation is ____°
Answer
-150
Card 37
Lead ____ is created by making the legs positive and the other limbs negative. Its angle of orientation is +90°
Answer
aVF
Card 38
Lead aVF is created by making the legs positive and the other limbs negative. Its angle of orientation is ____°
Answer
+90
Card 39
Leads ____, ____, and ____ are called the inferior leads
Answer
II
III
aVF
Card 40
Leads ____ and ____ are often called the left lateral leads
Answer
I
aVL
Card 41
____ is the only true right-sided limb lead.
Answer
aVR
Card 42
Which precordial lead(s) are the anterior leads?
____
Answer
V2, V3, V4
Card 43
Which of the precordial lead(s) are the left lateral leads?
____
Answer
V5, V6
Card 44
Which of the precordial lead(s) are referred to as the right ventricular leads?
____
Answer
V1
Card 45
Degrees and lead?
Answer
See the picture.
Card 46
Degrees and lead?
Answer
See the picture.
Card 47
Degrees and lead?
Answer
See the picture.
Card 48
Degrees and lead?
Answer
See the picture.
Card 49
Degrees and lead?
Answer
See the picture.
Card 50
Degrees?
Answer
See the picture.
Card 51
Degrees and lead?
Answer
See the picture.
Card 52
Degrees?
Answer
See the picture.
Card 53
The PR interval normally lasts from ____ to ____ seconds (3 to 5 mm on the EKG paper
Answer
0.12
0.2
Card 54
The PR interval normally lasts from 0.12 to 0.2 seconds (____ to ____ mm on the EKG paper
Answer
3
5
Card 55
During R wave progression, lead ____ has the smallest R wave and lead ____ the largest
Answer
V1
V5
the R wave in lead V6 is normally a little smaller than that in lead V5
Card 56
During R wave progression, the normal transition zone is at leads ____ or ____
Answer
V3
V4
the R wave in lead V6 is normally a little smaller than that in lead V5
Card 57
A normal QRS interval is ____ to ____ seconds in duration.
Answer
0.06
0.1
It shouldn't be any wider than one little square
represents the duration of the QRS complex
Card 58
The amplitude, or height, of a normal T wave is ____
Answer
one-third to two-thirds that of the corresponding R wave
Card 59
How can you tell if a QT interval is normal?
____
Answer
It is less than half the R-R interval (about 40%)
Card 60
The P wave is small and usually positive in the ____ and ____ leads (not specific)
Answer
left lateral
inferior
Card 61
The P wave is often biphasic in leads ____ and ____
Answer
III
V1
Card 62
The P wave is most positive in lead ____
Answer
II
Card 63
The P wave is most negative in lead ____
Answer
aVR
Card 64
In the QRS complex, a small initial Q wave represents ____
Answer
septal depolarization
can often be seen in one or several of the left lateral leads, and sometimes in the inferior leads.
Card 65
Most hypertrophy is caused by ____ overload
Answer
pressure
The heart is forced to pump against increased resistance
ex. systemic hypertension or aortic stenosis
Card 66
Enlargement is typically caused by ____ overload
Answer
volume
The chamber dilates to accommodate an increased amount of blood
Enlargement is most often seen with certain valvular diseases. Aortic insufficiency, for example, may cause left ventricular enlargement, and mitral insufficiency may result in left atrial enlargement.
Card 67
What are the 3 changes that can be seen on EKG when a chamber of the heart hypertrophies or enlarges?
1. ____
2. ____
3. ____
Answer
The chamber can take longer to depolarize. The EKG wave may therefore increase in duration.
The chamber can generate more current and thus a larger voltage. The wave may therefore increase in amplitude.
A larger percentage of the total electrical current can move through the expanded chamber. The mean electrical vector, or what we call the electrical axis, of the EKG wave may therefore shift.
Card 68
Which wave shows hypertrophy/enlargement of the heart?
____
Answer
B
(A) A normal wave. (B) The same wave when the chamber has enlarged or hypertrophied. The amplitude and duration of the wave have increased
Card 69
The normal QRS electrical axis lies between ____° and ____°
Answer
+90
-30
Card 70
If the QRS complex is predominantly positive in leads I and aVF then the QRS axis must be ____.
Answer
normal
Card 71
QRS complexes that are predominantly negative in lead ____ can still be normal axis if the QRS complexes in lead I and lead II are positive
Answer
aVF
this would put the axis in the -30° range
Card 72
QRS complexes that are predominantly negative in lead aVF can still be normal axis if the QRS complexes in lead ____ and lead ____ are positive
Answer
I
II
this would put the axis in the -30° range
Card 73
How do you determine if the axis is normal?
____
Answer
1. Let your R thumb be lead 1 and L thumb aVF
2. Which ever thumb is down is the direction of axis deviation
3. Check lead II if aVf is neg
QRS complexes that are predominantly negative in lead aVF can still be normal if the QRS complexes in lead I and lead II are positive
Card 74
How do you determine axis if a cardiologist is watching?
____
Answer
Look for the limb lead in which the QRS complex is most nearly biphasic. The axis has to be perpendicular to that lead
Card 75
If the axis lies between ____° and ____° we speak of right axis deviation
Answer
90
180
Card 76
If the axis lies between 90° and 180° we speak of ____ axis deviation
Answer
right
Card 77
If the QRS complex in lead aVF is ____ and lead I is ____, there is right axis devation
Answer
positive
negative
Card 78
If the QRS complex in lead aVF is positive and lead I is negative, there is ____ axis devation
Answer
right
Card 79
If the axis lies between ____° and ____°, we speak of left axis deviation
Answer
0
-90
Card 80
If the axis lies between 0° and -90°, we speak of ____ axis deviation
Answer
left
Card 81
If the QRS complex in lead I is ____ lead aVF is ____, then there is left axis deviation
Answer
positive
negative
Card 82
If the QRS complex in lead I is positive lead aVF is negative, then there is ____ axis deviation
Answer
left
Card 83
In rare instances, the axis becomes totally disoriented and lies between ____° and ____° This is called extreme right axis deviation. The QRS complex in both lead aVF and lead I will be negative.
Answer
-90
180
Card 84
In rare instances, the axis becomes totally disoriented and lies between -90° and 180° This is called extreme right axis deviation. The QRS complex in both lead ____ and lead ____ will be negative.
Answer
aVF
I
Card 85
In rare instances, the axis becomes totally disoriented and lies between -90° and 180° This is called extreme right axis deviation. The QRS complex in both lead aVF and lead I will be ____.
Answer
negative
Card 86
What is the axis?
____
Answer
Left axis deviation
This patient has left axis deviation; the QRS complex is predominantly positive in lead I and negative in lead aVF.
The QRS complex in lead aVR is approximately biphasic; therefore, the electrical axis must lie nearly perpendicular to it, that is, at either -60° or +120° Because we already know that the axis falls within the zone of left axis deviation (i.e., between 0° and -90°), the correct axis must be -60°
Card 87
The normal P-wave axis lies approximately between ____° and ____° in adults
Answer
0
70
Card 88
The normal P-wave axis lies approximately between ____° and ____° in children
Answer
0
90
Card 89
The T-wave axis is variable, but it should approximate the QRS axis, lying within ____° to ____° of the QRS axis.
Answer
50
60
Card 90
What is the axis of the QRS complex (Cardiologist method)?
____
Answer
about 0°
The QRS complex: the QRS axis is about 0°. It is nearly biphasic in aVF, implying an axis of 0° or 180°. Because the QRS complex in lead I has a tall R wave, the axis must be 0°.
The P wave: in lead aVL, the P wave is virtually invisible (isoelectric), so the P-wave axis must lie perpendicular to this lead and is either 60° or -120°. Since the P wave is positive in leads I and aVF. the axis must be 60°
The T wave: all of the leads with tall R waves have positive T waves. The T waves are flat in lead III, indicating an axis perpendicular to lead III (either +30° or -150°). Because there is a tall T wave in lead I, the axis must be about +30°
Card 91
What is the axis of the P wave?
____
Answer
about 60°
The QRS complex: the QRS axis is about 0°. It is nearly biphasic in aVF, implying an axis of 0° or 180°. Because the QRS complex in lead I has a tall R wave, the axis must be 0°.
The P wave: in lead aVL, the P wave is virtually invisible (isoelectric), so the P-wave axis must lie perpendicular to this lead and is either 60° or -120°. Since the P wave is positive in leads I and aVF. the axis must be 60°
The T wave: all of the leads with tall R waves have positive T waves. The T waves are flat in lead III, indicating an axis perpendicular to lead III (either +30° or -150°). Because there is a tall T wave in lead I, the axis must be about +30°
Card 92
What is the axis of the T wave?
____
Answer
about +30°
The QRS complex: the QRS axis is about 0°. It is nearly biphasic in aVF, implying an axis of 0° or 180°. Because the QRS complex in lead I has a tall R wave, the axis must be 0°.
The P wave: in lead aVL, the P wave is virtually invisible (isoelectric), so the P-wave axis must lie perpendicular to this lead and is either 60° or -120°. Since the P wave is positive in leads I and aVF. the axis must be 60°
The T wave: all of the leads with tall R waves have positive T waves. The T waves are flat in lead III, indicating an axis perpendicular to lead III (either +30° or -150°). Because there is a tall T wave in lead I, the axis must be about +30°
Card 93
Virtually all of the information you need to assess atrial enlargement can be found in leads ____ and ____
Answer
II
V1
Lead II is useful because it is oriented nearly parallel to the flow of current through the atria (i.e., parallel to the mean P-wave vector). It therefore records the largest positive deflection and is very sensitive to any perturbations in atrial depolarization.
Lead V1 is useful because it is oriented perpendicularly to the flow of electricity and is therefore biphasic, allowing easy separation of the right and left atrial components.
Card 94
With ____ atrial enlargement, the amplitude of the first portion of the P wave increases
Answer
right
With right atrial enlargement, the amplitude of the first portion of the P wave increases. The width does not change because the terminal component of the P wave is left atrial in origin, and this remains unchanged.
Card 95
With right atrial enlargement, the amplitude of the ____ portion of the P wave increases
Answer
first
With right atrial enlargement, the amplitude of the first portion of the P wave increases. The width does not change because the terminal component of the P wave is left atrial in origin, and this remains unchanged.
Card 96
How is the width of the P wave affected by right atrial enlargement?
____
Answer
it's unchanged :)
With right atrial enlargement, the amplitude of the first portion of the P wave increases. The width does not change because the terminal component of the P wave is left atrial in origin, and this remains unchanged.
Card 97
With right atrial enlargement, the tallest P wave may be seen in leads ____ or ____
Answer
aVF
III
Instead of the usual lead II
Card 98
What do these P waves show?
____
Answer
Right atrial enlargement
Card 99
____ atrial enlargement is diagnosed by the presence of P waves with an amplitude exceeding 2.5 mm in at least one of the inferior (II, III, aVF) leads
Answer
Right
Card 100
Right atrial enlargement is diagnosed by the presence of P waves with an amplitude exceeding ____ mm in at least one of the inferior (II, III, aVF) leads
Answer
2.5
Card 101
Right atrial enlargement is diagnosed by the presence of P waves with an amplitude exceeding 2.5 mm in at least one of the ____ leads
Answer
inferior (II, III, aVF)
Card 102
With ____ atrial enlargement, the amplitude of the second portion of the P wave may increase
Answer
left
Card 103
With left atrial enlargement, the amplitude of the ____ portion of the P wave may increase
Answer
second
Card 104
How is the duration of the P wave affected by left atrial enlargement?
____
Answer
increased
Card 105
The diagnosis of ____ atrial enlargement requires that the terminal portion of the P wave should drop more than 1 mm below the isoelectric line in lead V1
Answer
left
remember that lead V1 overlies the right heart, so when an enlarged left atrium depolarizes, the result will be a larger negative deflection in lead V1
Card 106
The diagnosis of left atrial enlargement requires that the terminal portion of the P wave should ____ (↑/↓) more than 1 mm below the isoelectric line in lead V1
Answer
drop
remember that lead V1 overlies the right heart, so when an enlarged left atrium depolarizes, the result will be a larger negative deflection in lead V1
Card 107
The diagnosis of left atrial enlargement requires that the terminal portion of the P wave should drop more than ____ mm below the isoelectric line in lead V1
Answer
1
remember that lead V1 overlies the right heart, so when an enlarged left atrium depolarizes, the result will be a larger negative deflection in lead V1
Card 108
The diagnosis of left atrial enlargement requires that the terminal portion of the P wave should drop more than 1 mm below the isoelectric line in lead ____
Answer
V1
remember that lead V1 overlies the right heart, so when an enlarged left atrium depolarizes, the result will be a larger negative deflection in lead V1
Card 109
The diagnosis of left atrial enlargement requires that the terminal portion of the P wave should be at least ____ in width.
Answer
1 small block (0.04 second)
Card 110
The classic picture of right atrial enlargement is called ____ because it is often caused by ____ disease.
Answer
P pulmonale
severe lung
Card 111
The classic picture of left atrial enlargement is called ____ because it is often caused by ____ disease.
Answer
P mitrale
mitral valve
Card 112
What do these P waves show?
____
Answer
left atrial enlargement
Card 113
Right atrial enlargement is characterized by:
1. ____
2. ____
3. ____
Answer
P waves with an amplitude exceeding 2.5 mm in the inferior leads
No change in the duration of the P wave
Possible right axis deviation of the P wave
Card 114
Left atrial enlargement is characterized by:
1. ____
2. ____
3. ____
Answer
The amplitude of the terminal (negative) component of the P wave may be increased and must descend at least 1 mm below the isoelectric line in lead V1
The duration of the P wave is increased, and the terminal (negative) portion of the P wave must be at least 1 small block (0.04 second) in width
No significant axis deviation is seen because the left atrium is normally electrically dominant
Card 115
In right ventricular hypertrophy, ____ axis deviation is present, with the QRS axis exceeding ____°
Answer
right
+100
Card 116
In right ventricular hypertrophy, the R wave is ____ (smaller/larger) than the S wave in lead V1, and the S wave is ____ (smaller/larger) than the R wave in lead V6.
Answer
larger
Card 117
In right ventricular hypertrophy, the R wave is larger than the S wave in lead ____, and the S wave is larger than the R wave in lead ____.
Answer
V1
V6
Card 118
What does this show?
____
Answer
Right ventricle hypertrophy
Card 119
The most common causes of right ventricular hypertrophy are ____ disease and ____ disease.
Answer
pulmonary
congenital heart
Card 120
In left ventricular hypertrophy, there should be increased ____-wave amplitude in leads overlying the left ventricle and increased ____-wave amplitude in leads overlying the right ventricle
Answer
R
S
Increasing R-wave amplitude in the leads overlying the left ventricle forms the basis of diagnosing left ventricular hypertrophy
Card 121
In left ventricular hypertrophy, there should be increased R-wave amplitude in leads overlying the ____ ventricle and increased S-wave amplitude in leads overlying the ____ ventricle
Answer
left
right
Increasing R-wave amplitude in the leads overlying the left ventricle forms the basis of diagnosing left ventricular hypertrophy
Card 122
The 4 most useful criteria for left ventricular hypertrophy are:
1. ____
2. ____
3. ____
4. ____
Answer
The R-wave amplitude in lead V5 or V6 plus the S wave amplitude in lead V1 or V2 exceeds 35 mm
The R-wave in lead aVL exceeds 11 mm
The R-wave in aVL plus the S wave in lead V3 exceeds 20 mm in women and 28 in men
Left axis deviation of > -15°
Card 123
The left ventricular hypertrophy criteria are are of little value in ____
Answer
individuals younger than 35 years of age and especially children
Frequently have increased voltage due to a relatively thin chest wall
These criteria are particularly unreliable in young children
Card 124
What do these leads show?
____
Answer
left ventricle hypertrophy
Card 125
The leading causes of left ventricular hypertrophy are ____ and ____
Answer
systemic hypertension
valvular disease
Card 126
Both right and left ventricular hypertrophy may slightly prolong the QRS complex, but rarely beyond ____ second
Answer
0.1
electrical activity is still being conducted along the normal paths
Card 127
What EKG findings are seen when both ventricles are hypertrophic?
____
Answer
There may be a combination of features (e.g., criteria for left ventricular hypertrophy in the precordial leads with right axis deviation in the limb leads), but in most cases, the effects of the usually dominant left ventricle obscure those of the right ventricle.
Card 128
What does this EKG show?
____
Answer
Left ventricle hypertrophy
Card 129
One of the criteria for left ventricle hypertrophy is the ____-wave amplitude in lead V5 or V6 plus the ____ wave amplitude in lead V1 or V2 exceeds 35 mm
Answer
R
S
Card 130
One of the criteria for left ventricle hypertrophy is the R-wave amplitude in lead ____ or ____ plus the S wave amplitude in lead ____ or ____ exceeds 35 mm
Answer
V5
V6
V1
V2
Card 131
One of the criteria for left ventricle hypertrophy is the R-wave amplitude in lead V5 or V6 plus the S wave amplitude in lead V1 or V2 exceeds ____ mm
Answer
35
Card 132
One of the criteria for left ventricle hypertrophy is the R-wave in lead aVL exceeds ____ mm
Answer
11
Card 133
One of the criteria for left ventricle hypertrophy is the ____-wave in ____ plus the ____ wave in lead ____ exceeds 20 mm in women and 28 in men
Answer
R
aVL
S
V3
Card 134
One of the criteria for left ventricle hypertrophy is the R-wave in aVL plus the S wave in lead V3 exceeds ____ mm in women and ____ in men
Answer
20
28
Card 135
One of the criteria for left ventricle hypertrophy is left axis deviation of ____°
Answer
> -15
Card 136
What is the most accurate single criterion for left ventricle hypertrophy?
____
Answer
the R-wave amplitude in aVL plus the S-wave amplitude in V3 exceeds 20 for women and 28 for men
Card 137
Secondary repolarization abnormalities include ____ and ____
Secondary repolarization abnormalities usually accompany ____ and may even herald the onset of ventricular dilatation
Answer
severe hypertrophy
For example, a patient with aortic stenosis and no clinical symptoms may show a stable pattern of left ventricular hypertrophy for years. Eventually, however, the left ventricle may fail, and the patient will develop severe shortness of breath and other symptoms of congestive heart failure. The EKG may then show left ventricular hypertrophy with secondary repolarization abnormalities. This progression is illustrated in the two EKGs below.
Card 139
Secondary repolarization abnormalities usually accompany severe hypertrophy and may even herald the onset of ____
Answer
ventricular dilatation
For example, a patient with aortic stenosis and no clinical symptoms may show a stable pattern of left ventricular hypertrophy for years. Eventually, however, the left ventricle may fail, and the patient will develop severe shortness of breath and other symptoms of congestive heart failure. The EKG may then show left ventricular hypertrophy with secondary repolarization abnormalities. This progression is illustrated in the two EKGs below.
Card 140
T-wave inversion in ischemia is ____ (symmetrical/asymmetrical)
Answer
symmetrical
One of the key ways to tell ischemia from secondary repolarization
-asymmetric with secondary repolarization abnormalities
-symmetric with cardiac ischemia
Card 141
T-wave inversion in secondary repolarization is ____ (symmetrical/asymmetrical)
Answer
asymmetrical
One of the key ways to tell ischemia from secondary repolarization
-asymmetric with secondary repolarization abnormalities
-symmetric with cardiac ischemia
Card 142
The mnemonic ____ should help you remember the arrhythmogenic factors
Answer
HIS DEBS
Card 143
The mnemonic HIS DEBS should help you remember the arrhythmogenic factors:
H - ____
I - ____
S - ____
D - Drugs
E - Electrolyte Disturbances
B - Bradycardia
S - Stretch
Answer
Hypoxia
Ischemia and Irritability
Sympathetic Stimulation
Card 144
The mnemonic HIS DEBS should help you remember the arrhythmogenic factors:
H - Hypoxia
I - Ischemia and Irritability
S - Sympathetic Stimulation
D - ____
E - ____
B - ____
S - ____
What is the rule for counting heart rate from the first 6 lines on an EKG (following the first R wave on a thick line)?
____
Answer
300, 150, 100, followed by 75, 60, and 50
divide 300 by the # of big boxes
Card 146
What is the heart rate?
____
Answer
75
Card 147
What is the heart rate?
____
Answer
60-55ish
Card 148
What is the heart rate?
____
Answer
150
Card 149
How can you determine heart rate in a very slow rhythm?
____
Answer
Count the number of cycles within 6 seconds and then x 10
Every EKG rhythm strip is marked at 3-second intervals, usually with a series of little lines (or slashes or dots) at the top or bottom of the strip. Count the number of cycles within two of these intervals (6 seconds) and multiply by 10 (10 x seconds = 60 seconds) to get the heart rate in beats per minute
Card 150
Just remember, the difficult arrhythmias are difficult for ____
Answer
everyone :)
including expert electrocardiographers!
Card 151
The electrical activity follows the usual conduction pathways, starting with depolarization of the sinus node, but it is too fast, too slow, or irregular. These are called ____.
Answer
arrhythmias of sinus origin
Card 152
When the electrical activity originates from a focus other than the sinus node, these are called ____ rhythms
Answer
ectopic
Card 153
When the electrical activity is trapped within an electrical racetrack whose shape and boundaries are determined by various anatomic or electrical myocardial configurations. These are called ____
Answer
reentrant arrhythmias
Card 154
When the electrical activity originates in the sinus node and follows the usual pathways but encounters unexpected blocks and delays. These are called ____
Answer
conduction blocks
Card 155
The electrical activity follows anomalous accessory conduction pathways that bypass the normal ones, providing an electrical shortcut, or short circuit. These arrhythmias are termed ____
Answer
preexcitation syndromes
Card 156
Normal heart rate is between ____ and ____ beats per minute
Answer
60
100
Card 157
What rhythm is this?
____
Answer
sinus tachycardia
Each beat is separated by two and one-half large squares for a rate of 120 beats per minute
Card 158
What rhythm is this?
____
Answer
sinus bradycardia
More than seven large squares separate each beat, and the rate is 40 to 45 beats per minute.
Card 159
____ is a normal rhythm that appears to be slightly irregular
Answer
Sinus arrhythmia
Inspiration accelerates the heart rate, and expiration slows it down
Card 160
____ occurs when the sinus node stops firing.
Answer
Sinus arrest
Card 161
Under normal circumstances, the pacemaker is the ____
Answer
sinus node
Card 162
The sinus node ____ the other pacemaker cells by delivering its wave of depolarization throughout the myocardium before its potential competitors can complete their own spontaneous depolarization
Answer
overdrives
Card 163
With sinus arrest, these other pacemakers can spring into action in a kind of rescue mission. These rescue beats are called ____
Answer
escape beats
Card 164
____ pacemakers usually discharge at a rate of 60 to 75 beats per minute
Answer
Atrial
Card 165
Atrial pacemakers usually discharge at a rate of ____ to ____ beats per minute
Answer
60
75
Card 166
Pacemaker cells located near the AV node, called ____, typically discharge at 40 to 60 beats per minute
Answer
junctional pacemakers
Card 167
Pacemaker cells located near the AV node, called junctional pacemakers, typically discharge at ____ to ____ beats per minute
Answer
40
60
Card 168
____ pacemaker cells usually discharge at 30 to 45 beats per minute.
Answer
Ventricular
Card 169
Ventricular pacemaker cells usually discharge at ____ to ____ beats per minute.
Answer
30
45
Card 170
Of all of the available escape mechanisms, ____ escape is by far the most common
Answer
junctional
Card 171
In junctional escape, a ____ is not seen
Answer
normal P wave
Often no P wave at all
Card 172
Occasionally in junctional escape, a ____ P wave can be seen
Answer
retrograde
Card 173
A ____ P wave is upright in lead aVR and inverted in lead II
Answer
retrograde
A normal P wave is upright in lead II and inverted in lead aVR wave is upright in lead
Card 174
A retrograde P wave is upright in lead ____ and inverted in lead ____
Answer
aVR
II
A normal P wave is upright in lead II and inverted in lead aVR wave is upright in lead
Card 175
What is this rhythm?
____
Answer
normal sinus
Card 176
What is this rhythm?
____
Answer
Sinus tachycardia
Card 177
What is this rhythm?
____
Answer
Sinus bradycardia
Card 178
What is this rhythm?
____
Answer
Sinus arrest or exit block
Card 179
What is this rhythm?
____
Answer
Sinus arrest or exit block with junctional escape
Card 180
What changes to this diagram would produce a reentrant rhythm?
____
Answer
Picture
Card 181
What are 4 questions to ask when assessing the rhythm?
1. ____
2. ____
3. ____
4. ____
Answer
Are normal P waves present?
Are the QRS complexes narrow or wide?
What is the relationship between the P waves and the QRS complexes? (is there 1 P wave for each QRS complex?)
Is the rhythm regular or irregular?
Card 182
If no P waves are present, then the rhythm must have originated from ____
Answer
below the atria
In the AV node or the ventricles
Card 183
The presence of P waves with an abnormal axis may reflect:
1. ____
2. ____
Answer
Activation of the atria from impulses originating from an atrial focus other than the sinus node
Retrograde activation from a site within the AV node or the ventricles, that is, from current flowing backward into the atria through the AV node or through an accessory pathway
can also be atrial enlargement
Card 184
A narrow normal QRS complex implies that ventricular depolarization is proceeding along ____ (normal/abnormal) pathways
Answer
normal
AV node to His bundle to bundle branches to Purkinje cells
This is the most efficient means of conduction, requiring the least amount of time, so the resulting QRS complex is of short duration (narrow)
Card 185
A ____ QRS complex, indicates that the origin of the rhythm must be at or above the AV node
Answer
narrow
Card 186
A narrow QRS complex, indicates that the origin of the rhythm must be ____ the AV node
Answer
at or above
Card 187
A ____ QRS complex, indicates that the origin of the rhythm must be below the AV node
Answer
wide
within the ventricles themselves
Card 188
A wide QRS complex, indicates that the origin of the rhythm must be ____ the AV node
Answer
below
within the ventricles themselves
Card 189
If the P wave and QRS complexes correlate in the usual one-to-one fashion, the rhythm almost certainly has a ____ origin
Answer
sinus or other atrial
Card 190
A lack of correlation between the P waves and QRS complexes is called ____.
Answer
AV dissociation
Card 191
____ are single ectopic supraventricular beats that originate in the atria
Answer
Premature atrial contractions (PACs)
Card 192
____ premature beats are single ectopic supraventricular beats can originate near the AV node
Answer
Junctional
Card 193
What does this show?
____
Answer
premature atrial beat
The third beat is an atrial premature beat. Note how the Pwave contour of the premature beat differs from that of the normal sinus beat
Card 194
What does this show?
____
Answer
junctional premature beat
The fourth beat is a junctional premature beat. There is no P wave preceding the premature QRS complex.
Card 195
An atrial premature beat can be distinguished from a normal sinus beat by the ____ and by the ____
Answer
contour of the P wave
timing of the beat
Contour: Because an atrial premature beat originates at an atrial site distant from the sinus node, atrial depolarization does not occur in the usual manner, and the configuration of the resultant P wave differs from that of the sinus P waves. If the site of origin of the atrial premature beat is far from the sinus node, the axis of the atrial premature beat will also differ from that of the normal P waves.
Timing: An atrial premature beat comes too early; that is, it intrudes itself before the next anticipated sinus wave.
Card 196
What does this show?
____
Answer
premature atrial beat
The third beat is an atrial premature beat. The P wave is shaped differently from the other, somewhat unusual-looking P waves, and the beat is clearly premature.
Card 197
What is the difference between a junctional premature beat and a junctional escape beat?
____
Answer
They look exactly alike, but the junctional premature beat occurs early, prematurely, interposing itself into the normal sinus rhythm. An escape beat occurs late, following a pause when the sinus node has failed to fire.
Card 198
What does this show?
____
Answer
junctional premature beat
Card 199
What does this show?
____
Answer
junctional escape beat
Card 200
A premature P wave without an ensuing QRS is called a ____
Answer
blocked atrial premature contraction
Card 201
What causes a blocked premature atrial contraction?
____
Answer
Beat may occurs so early that the AV node will not have recovered and can't conduct the atrial premature beat into the ventricles
Card 202
What does this show?
____
Answer
blocked atrial premature contraction
Card 203
____ is still referred to by some old school cardiologists as paroxysmal supraventricular tachycardia
Answer
AV nodal reentrant tachycardia (AVNRT)
Card 204
AV nodal reentrant tachycardia (AVNRT) is still referred to by some old school cardiologists as ____
Answer
paroxysmal supraventricular tachycardia
Card 205
AVNRT has a sudden onset and is usually precipated by a ____
Answer
premature supraventricular beat (atrial or junctional)
(A-C) AVNRT in four different patients.
A shows simultaneous activation of the atria and ventricles; therefore, the retrograde P waves are lost in the QRS complexes. B shows a supraventricular tachycardia mimicking a more serious rhythm called ventricular tachycardia. In C, retrograde P waves can be seen. (D) A good example of the pseudo-R' configuration in lead V1 representing the retrograde P waves (arrows) of AVNRT. (E) The AV node is usually the site of the reentrant circuit that causes the arrhythmia. Atrial depolarization therefore occurs in reverse, and if P waves can be seen, their axis will be shifted nearly 180° from normal (that is why these are called retrograde P waves).
Card 206
____, ____, or ____ can cause AVNRT
Answer
Alcohol
coffee
excitement
(A-C) AVNRT in four different patients.
A shows simultaneous activation of the atria and ventricles; therefore, the retrograde P waves are lost in the QRS complexes. B shows a supraventricular tachycardia mimicking a more serious rhythm called ventricular tachycardia. In C, retrograde P waves can be seen. (D) A good example of the pseudo-R' configuration in lead V1 representing the retrograde P waves (arrows) of AVNRT. (E) The AV node is usually the site of the reentrant circuit that causes the arrhythmia. Atrial depolarization therefore occurs in reverse, and if P waves can be seen, their axis will be shifted nearly 180° from normal (that is why these are called retrograde P waves).
Card 207
Can AVNRT occur in healthy hearts?
____
Answer
yes
(A-C) AVNRT in four different patients.
A shows simultaneous activation of the atria and ventricles; therefore, the retrograde P waves are lost in the QRS complexes. B shows a supraventricular tachycardia mimicking a more serious rhythm called ventricular tachycardia. In C, retrograde P waves can be seen. (D) A good example of the pseudo-R' configuration in lead V1 representing the retrograde P waves (arrows) of AVNRT. (E) The AV node is usually the site of the reentrant circuit that causes the arrhythmia. Atrial depolarization therefore occurs in reverse, and if P waves can be seen, their axis will be shifted nearly 180° from normal (that is why these are called retrograde P waves).
Card 208
Is AVNRT a regular or irregular rhythm?
____
Answer
regular
(A-C) AVNRT in four different patients.
A shows simultaneous activation of the atria and ventricles; therefore, the retrograde P waves are lost in the QRS complexes. B shows a supraventricular tachycardia mimicking a more serious rhythm called ventricular tachycardia. In C, retrograde P waves can be seen. (D) A good example of the pseudo-R' configuration in lead V1 representing the retrograde P waves (arrows) of AVNRT. (E) The AV node is usually the site of the reentrant circuit that causes the arrhythmia. Atrial depolarization therefore occurs in reverse, and if P waves can be seen, their axis will be shifted nearly 180° from normal (that is why these are called retrograde P waves).
Card 209
____ is most often driven by a reentrant circuit looping within the AV node
Answer
AVNRT
(A-C) AVNRT in four different patients.
A shows simultaneous activation of the atria and ventricles; therefore, the retrograde P waves are lost in the QRS complexes. B shows a supraventricular tachycardia mimicking a more serious rhythm called ventricular tachycardia. In C, retrograde P waves can be seen. (D) A good example of the pseudo-R' configuration in lead V1 representing the retrograde P waves (arrows) of AVNRT. (E) The AV node is usually the site of the reentrant circuit that causes the arrhythmia. Atrial depolarization therefore occurs in reverse, and if P waves can be seen, their axis will be shifted nearly 180° from normal (that is why these are called retrograde P waves).
Card 210
AVNRT is most often driven by a reentrant circuit looping within the ____
Answer
AV node
(A-C) AVNRT in four different patients.
A shows simultaneous activation of the atria and ventricles; therefore, the retrograde P waves are lost in the QRS complexes. B shows a supraventricular tachycardia mimicking a more serious rhythm called ventricular tachycardia. In C, retrograde P waves can be seen. (D) A good example of the pseudo-R' configuration in lead V1 representing the retrograde P waves (arrows) of AVNRT. (E) The AV node is usually the site of the reentrant circuit that causes the arrhythmia. Atrial depolarization therefore occurs in reverse, and if P waves can be seen, their axis will be shifted nearly 180° from normal (that is why these are called retrograde P waves).
Card 211
What are 3 things that can indicate AVNRT?
1. ____
2. ____
3. ____
Answer
Retrograde P waves in leads II or III (rare)
pseudo-R' in lead V1
P waves are buried within the QRS (most common)
(A-C) AVNRT in four different patients.
A shows simultaneous activation of the atria and ventricles; therefore, the retrograde P waves are lost in the QRS complexes. B shows a supraventricular tachycardia mimicking a more serious rhythm called ventricular tachycardia. In C, retrograde P waves can be seen. (D) A good example of the pseudo-R' configuration in lead V1 representing the retrograde P waves (arrows) of AVNRT. (E) The AV node is usually the site of the reentrant circuit that causes the arrhythmia. Atrial depolarization therefore occurs in reverse, and if P waves can be seen, their axis will be shifted nearly 180° from normal (that is why these are called retrograde P waves).
Card 212
What is this an example of?
____
Answer
pseudo-R' in AVNRT
Seen in lead V1
(A-C) AVNRT in four different patients.
A shows simultaneous activation of the atria and ventricles; therefore, the retrograde P waves are lost in the QRS complexes. B shows a supraventricular tachycardia mimicking a more serious rhythm called ventricular tachycardia. In C, retrograde P waves can be seen. (D) A good example of the pseudo-R' configuration in lead V1 representing the retrograde P waves (arrows) of AVNRT. (E) The AV node is usually the site of the reentrant circuit that causes the arrhythmia. Atrial depolarization therefore occurs in reverse, and if P waves can be seen, their axis will be shifted nearly 180° from normal (that is why these are called retrograde P waves).
Card 213
What is this an example of?
____
Answer
retrograde P waves in AVNRT
Most common in lead II or III
(A-C) AVNRT in four different patients.
A shows simultaneous activation of the atria and ventricles; therefore, the retrograde P waves are lost in the QRS complexes. B shows a supraventricular tachycardia mimicking a more serious rhythm called ventricular tachycardia. In C, retrograde P waves can be seen. (D) A good example of the pseudo-R' configuration in lead V1 representing the retrograde P waves (arrows) of AVNRT. (E) The AV node is usually the site of the reentrant circuit that causes the arrhythmia. Atrial depolarization therefore occurs in reverse, and if P waves can be seen, their axis will be shifted nearly 180° from normal (that is why these are called retrograde P waves).
Card 214
What is this an example of?
____
Answer
buried P waves in AVNRT
(A-C) AVNRT in four different patients.
A shows simultaneous activation of the atria and ventricles; therefore, the retrograde P waves are lost in the QRS complexes. B shows a supraventricular tachycardia mimicking a more serious rhythm called ventricular tachycardia. In C, retrograde P waves can be seen. (D) A good example of the pseudo-R' configuration in lead V1 representing the retrograde P waves (arrows) of AVNRT. (E) The AV node is usually the site of the reentrant circuit that causes the arrhythmia. Atrial depolarization therefore occurs in reverse, and if P waves can be seen, their axis will be shifted nearly 180° from normal (that is why these are called retrograde P waves).
Card 215
____ can help to diagnose and terminate an episode of AVNRT
Answer
Massaging the carotid artery
Card 216
What is this rhythm?
____
Answer
3:1 AV flutter
Card 217
____ is generated by a reentrant circuit that runs largely around the annulus of the tricuspid valve
Answer
Atrial flutter
Card 218
Atrial flutter is generated by a reentrant circuit that runs largely around the ____
Answer
annulus of the tricuspid valve
Card 219
Is the reentrant circuit going clockwise or counterclockwise around the tricuspid in this atrial flutter?
Lead II:
____
Answer
counterclockwise
Card 220
In ____, multiple tiny reentrant circuits whirl around in totally unpredictable fashion
Answer
atrial fibrillation
Card 221
The irregularly irregular appearance of QRS complexes and the absence of discrete P waves is the key to identifying ____
Answer
atrial fibrillation
Card 222
What is this rhythm?
____
Answer
a fib
Card 223
What is this rhythm?
____
Answer
a fib
Card 224
____ is the most common and clinically significant sustained arrhythmia in the general population. It is especially common in the elderly population
Answer
Atrial fibrillation
Card 225
Atrial fibrillation is the most common and clinically significant sustained arrhythmia in the general population. It is especially common in the ____ population
Answer
elderly
Card 226
The 4 most common cardiovascular causes of atrial fibrillation are:
1. ____
2. ____
3. ____
4. ____
Lifestyle risk factors for atrial fibrillation include ____ and ____
Answer
obesity
alcoholism
Card 228
____ is an important cause of nocturnal atrial fibrillation
Answer
Obstructive sleep apnea
Card 229
You often won’t be able to identify an acute precipitant in patients with atrial fibrillation, but keep in mind the possibility of a ____, ____, and ____ (serious causes)
Answer
pulmonary embolism
thyrotoxicosis
pericarditis
Card 230
Multifocal atrial tachycardia with a rate less than 100 beats per minute is often called ____
Answer
a wandering atrial pacemaker
Card 231
Multifocal atrial tachycardia (MAT) is very common in patients with ____
Answer
severe lung disease
Card 232
Multifocal atrial tachycardia (MAT) can be distinguished from atrial fibrillation by ____
Answer
the easily identifiable P waves occurring before each QRS complex
Card 233
What are 3 characteristics of multifocal atrial tachycardia (MAT)?
1. ____
2. ____
3. ____
Answer
Three different P wave morphologies
Variable PR interval
Irregular ventricular rate
Card 234
What is this rhythm?
____
Answer
Multifocal atrial tachycardia (MAT)
Card 235
How can paroxysmal atrial tachycardia (PAT) be distinguished from AVNRT?
____
Answer
Many times, you can’t. However, if you see a warm-up or cool-down period on the EKG, the rhythm is likely to be PAT
Carotid massage will slow or terminate AVNRT, whereas it has virtually no effect on PAT
Card 236
What is this rhythm?
____
Answer
paroxysmal atrial tachycardia
P waves are not always visible, but here they can be seen fairly easily. You may also notice the varying distance between the P waves and the ensuing QRS complexes; this reflects a varying conduction delay between the atria and ventricles that often accompanies PAT
Card 237
Remember: The key to diagnosing a supraventricular tachyarrhythma is to look for ____. They are most likely to be prominent in leads II and V1
Answer
P waves
Card 238
Remember: The key to diagnosing a supraventricular tachyarrhythma is to look for P waves. They are most likely to be prominent in leads ____ and ____
Answer
II
V1
Card 239
____ arrhythmias are rhythm disturbances arising below the AV node.
Answer
Ventricular
Card 240
The QRS complex of a premature ventricular contraction (PVC) appears ____ because ventricular depolarization does not follow the normal ventricular conduction pathways
Answer
wide and bizarre
However, the QRS complex may not appear wide in all leads, so scan the entire 12-lead EKG
Card 241
The QRS complex of a premature ventricular contraction (PVC) appears wide and bizarre because ____
Answer
ventricular depolarization does not follow the normal ventricular conduction pathways
However, the QRS complex may not appear wide in all leads, so scan the entire 12-lead EKG
Card 242
The QRS duration must be at least ____ seconds in most leads to make the diagnosis of a PVC
Answer
0.12
Card 243
What happens to the P waves in premature ventricular contractions (PVCs)?
____
Answer
A retrograde P wave may sometimes be seen, but it is more common to see no P wave at all
Card 244
A premature ventricular contractions (PVC) is usually followed by a ____ before the next beat apppears
Answer
prolonged compensatory pause
Card 245
____ PVCs occur between two normally conducted beats without a compensatory pause
Answer
Interpolated
Card 246
Isolated premature ventricular contractions (PVCs) are common in normal hearts but in the setting of ____ they can trigger ventricular tachycardia or ventricular fibrillation
Answer
acute myocardial infarction
Card 247
Isolated premature ventricular contractions (PVCs) are common in normal hearts but in the setting of acute myocardial infarction they can trigger ____ or ____
Answer
ventricular tachycardia
ventricular fibrillation
Card 248
If PVCs constitute more than ____% of a patient’s heartbeats, this can lead to remodeling of the myocardium with the development of dilated cardiomyopathy
Answer
10
Card 249
The rules of malignancy for premature ventricular contractions (PVCs) are:
1. ____
2. ____
3. ____
4. ____
5. ____
Answer
Frequent PVCs
Runs of consecutive PVCs
Multiform PVCs
PVCs falling on the T wave of the previous beat
Any PVC occurring in the setting of an acute myocardial infarction
Card 250
What does this show?
____
Answer
premature ventricular contraction (PVC)
Card 251
What does this show?
____
Answer
bigeminy
Card 252
If the ratio is one normal sinus beat to one PVC, the rhythm is called ____
Answer
bigeminy
Trigeminy refers to two normal sinus beats for every one PVC, and so on.
Card 253
How many PVCs does this show?
____
Answer
3 PVCs
Card 254
What does this show?
____
Answer
PVC that falls on the T wave
Card 255
A run of three or more consecutive PVCs is called ____
Answer
ventricular tachycardia
Card 256
____ (Uniform/Polymorphic) ventricular tachycardia is more commonly associated with acute coronary ischemia, infarction, profound electrolyte disturbances, and conditions causing prolongation of the QT interval
Answer
Polymorphic
Card 257
Polymorphic ventricular tachycardia is more commonly associated with ____, ____, ____, and ____
Answer
acute coronary ischemia
infarction
profound electrolyte disturbances
conditions causing prolongation of the QT interval
Card 258
____ (Uniform/Polymorphic) ventricular tachycardia is more often seen with healed infarctions
Answer
Uniform
The scarred myocardium provides the substrate for the reentrant ventricular tachycardia
Card 259
Uniform ventricular tachycardia is more often seen with ____
Answer
healed infarctions
The scarred myocardium provides the substrate for the reentrant ventricular tachycardia
Card 260
What is this rhythm?
____
Answer
v tach turning into v fib
Card 261
What is this rhythm?
____
Answer
ventricular tachycardia
Card 262
What is this rhythm?
____
Answer
accelerated idioventricular rhythm
Card 263
Accelerated idioventricular rhythm is a benign rhythm that is sometimes seen during ____ or during ____
Answer
an acute infarction
the early hours following reperfusion
Card 264
A prolonged QT interval is generally the result of prolonged ____
Answer
ventricular repolarization
Card 265
A PVC falling during an elongated T wave can initiate ____
Answer
torsade de pointes
Card 266
____ looks just like ordinary, run-of-the-mill ventricular tachycardia, except that the QRS complexes spiral around the baseline, changing their axis and amplitude
What is one common instance in which supraventricular beats can produce wide QRS complexes?
____
Answer
a supraventricular beat is conducted aberrantly through the ventricles
Card 270
How can an atrial premature beat produce aberrancy?
____
Answer
occurs so early in the next cycle that the Purkinje fibers in the ventricles have not had a chance to repolarize fully
The right bundle branch is particulary sluggish about repolarizing
Card 271
A wide QRS complex can signify 2 things:
1. ____
2. ____
Answer
A beat originating within the ventricles
A supraventricular beat conducted aberrantly
Card 272
P wave before a wide QRS = ____ (PVC or aberrant supraventricular beat)
Answer
supraventricular beat conducted aberrantly
Card 273
No P wave before a wide QRS = ____ (PVC or aberrant supraventricular beat)
Answer
PVC
Card 274
____ (V tach/AVNRT) is usually seen in diseased hearts
Answer
Ventricular tachycardia
Card 275
Ventricular tachycardia is usually seen in ____ (healthy/diseased) hearts
Answer
diseased
Card 276
____ (V tach/AVNRT) is usually seen in healthy hearts
Answer
AVNRT
Card 277
AVNRT is usually seen in ____ (healthy/diseased) hearts
Answer
healthy
Card 278
Carotid massage may terminate ____ (V tach/AVNRT)
Answer
AVNRT
Card 279
A wide complex tachycardia with cannon A waves = ____ (V tach/AVNRT)
Answer
Ventricular tachycardia
Card 280
A wide complex tachycardia with AV dissociation = ____ (V tach/AVNRT)
Answer
Ventricular tachycardia
Absence of AV dissociation doesn't mean that it is AVNRT
Card 281
In AVNRT with aberrancy, the initial deflection of the QRS complex is usually in the ____ (same/opposite) direction as that of the normal QRS complex
Answer
same
Card 282
In ventricular tachycardia, the initial deflection of the QRS complex is usually in the ____ (same/opposite) direction as that of the normal QRS complex
Answer
opposite
Card 283
What are 3 EKG clues to determine if a wide complex tachycardia is AVNRT vs v tach?
1. ____
2. ____
3. ____
Answer
AV dissociation
Fusion beats
Initial QRS deflection
Card 284
The ____ phenomenon describes a wide, aberrantly conducted supraventricular beat occurring after a QRS complex that is preceded by a long pause
Answer
Ashman
commonly seen in a fib
Card 285
____ block refers to any conduction block between the sinus node and the terminal Purkinje fibers
Answer
AV
Note that this includes the AV node and His bundle
Card 286
____ block refers to a conduction block where the sinus node fires but the depolarization is not transmitted to the atrial tissue
Answer
Sinus node
Card 287
____ block refers a conduction block in one or both of the ventricular bundle branches
Answer
Bundle branch
Sometimes, only a part of the left bundle branch is blocked; this circumstance is called a fascicular block or a hemiblock