Chapter 5: Rhythm, Part 1: Arrhythmias of Focal Origin Flashcards
1
Q
Arrhythmia literally means…
A
…without rhythm.
p. 97
2
Q
All automaticity foci pace at a…
A
…regular rhythm.
p. 99
3
Q
In reality, a normal sinus rhythm varies _____________ with __________.
A
imperceptibly with respiration
p. 99
4
Q
Sinus arrhythmia is a normal but extremely _______ increase in _____ ____ during ___________, and an extremely minimal ________ in heart rate during __________.
A
minimal, heart rate, inspiration
decrease, expiration
(p. 100)
5
Q
The slight increase in the heart rate is due to ___________-activated ___________ stimulation of the SA Node. The slight decrease in pacing rate is due to __________-activated _______________ inhibition of the SA Node.
This phenomenon reminds us that sinus pacing is regulated by…
A
inspiration, sympathetic
expiration, parasympathetic
both divisions of the autonomic nervous system
(p. 100)
6
Q
A significant decrease in heart rate variability is actually…
A
…pathological and a valuable indicator of increased mortality.
(p. 100)
7
Q
The atrial conduction system consists of 3 specialized internodal tracts in the _____ ______, and 1 conduction tract that innervates the ____ ______.
A
right atrium
left atrium
(p. 101)
8
Q
What are the 3 internodal tracts in the right atrium?
A
the anterior, middle, and posterior
p. 101
9
Q
What is the conduction tract that innervates the left atrium?
A
Bachmann’s Bundle
p. 101
10
Q
Why are they referred to as internodal tracts?
A
Because they course from the SA node to the AV node. (p. 101)
11
Q
Bachmann’s Bundle originates in the __ ____ and distributes depolarization to the ____ ______.
A
SA Node
left atrium
(p. 101)
12
Q
Depolarization passing rapidly through the atrial conduction system does not ______ __ ___; however, depolarization of the ______ __________ produces a _ ____ on EKG.
A
record on EKG
atrial myocardium
P wave
(p. 101)
13
Q
Because there is a concentration of merging ______ __________ ______ in the immediate region of the __ ____ near the ________ _____, considerable automaticity activity originates in that area.
A
atrial conduction tracts
AV node
coronary sinus
(p. 101)
14
Q
The heart’s own venous drainage (i.e. from the __________) empties into the _____ ______ via the ________ _____.
A
myocardium
right atrium
coronary sinus
(p. 101)
15
Q
When the depolarization stimulus (passing down from the atria) reaches the __ ____, the stimulus _____ in the __ Node, producing a _____ __ ___.
A
AV Node, slows, AV, pause on EKG
p. 102
16
Q
Depolarization passing through the Purkinje fibers of the ventricular conduction system is ___ ____ to ______ __ ___; this is a form of “_________” __________.
A
too weak to record on EKG
“concealed” conduction
(p. 103)
17
Q
Depolarization proceeds _______ through the His bundle and right and left bundle branches and their subdivisions to rapidly transmit depolarization via the ________ ________ _________ to the ___________ surface of the ___________ myocardium.
A
rapidly, terminal Purkinje filaments, endocardial, ventricular
(p. 103)
18
Q
When the ___________ ___________ depolarizes, it produces a ___ _______ on EKG.
A
ventricular myocardium
QRS complex
(p. 103)
19
Q
Ventricular depolarization begins ______ down the ________________ ______, where the left bundle branch produces fine terminal filaments.
A
midway, interventricular septum
p. 104
20
Q
The right bundle branch does not _______ ________ _________ __ ___ ______.
As a result, ____-to-_____ depolarization of the septum occurs immediately before the rest of the ___________ __________ ___________.
A
produce terminal filaments in the septum.
left-to-right, ventricular myocardium depolarizes
(p. 104)
21
Q
Repolarization of the Purkinje fibers takes ______ than ventricular repolarization. That is, the end of the T wave marks the end of ___________ ______________; however, repolarization of the ________ ______ terminates a little later – beyond the end of the T wave. The final phase of Purkinje repolarization may record a _____ ____, the _ ____, on EKG.
A
longer ventricular repolarization, Purkinje fibers small hump, U wave (p. 104)
22
Q
A very _________ automaticity focus may suddenly pace _______.
A
irritable, rapidly
p. 105
23
Q
What are the 3 types of irregular (atrial) rhythms?
A
wandering pacemaker
multifocal atrial tachycardia
atrial fibrillation
(p. 107)
24
Q
Irregular (atrial) rhythms are usually caused by…
A
…multiple, active automaticity sites
p. 107
25
In some hearts with structural pathology or hypoxia, malfunctioning automaticity foci may suffer from ________ _____, whereby any incoming depolarization is blocked, "__________" them from _______ ______________ by any other source.
Such "protection" is not healthy. By being insensitive to passive depolarization, they ______ be _________-__________, while their own automaticity is still _________ to ___________ _______.
entrance block
"protecting"
passive depolarization
cannot
overdrive-suppressed
conducted to surrounding tissue.
(p. 107)
26
When an automaticity focus has entrance block, is it said to be ___________ (the focus _____, but can't be _________-__________).
parasystolic
paces
overdrive-suppressed
(p. 107)
27
Wandering pacemaker is an _________ rhythm produced by pacemaker activity "wandering" from the __ ____ to nearby ____________ ____.
irregular
SA node
automaticity foci
(p. 108)
28
P' is pronounced...
..."P prime"
| p. 108
29
What does P' represent?
Atrial depolarization by an automaticity focus, as opposed to normal sinus-paced P waves.
(p. 108)
30
In a given lead, each atrial automaticity focus produces its own...
...morphological signature. That is, it produces a P' wave of a distinctive shape related to the anatomical location of that focus within the atria.
(p. 108)
31
The 3 characteristics of a wandering pacemaker rhythm are:
P' wave _____ ______
Atrial rate ____ ____ ___
_________ ___________ rhythm, thus the _____ lengths vary.
shape varies
less than 100
Irregular ventricular, cycle
(p. 108)
32
Should a wandering pacemaker rate accelerate into a tachycardia, it becomes...
...multifocal atrial tachycardia.
| p. 108
33
Multifocal atrial tachycardia is a rhythm of patients with _______ ___________ _________ disease.
chronic obstructive pulmonary.
| p. 109
34
The heart rate in MAT is over ___ per minute with P' waves of various shapes, since ____ or more ______ ____ are involved.
100
three
atrial foci
(p. 109)
35
P' waves from the same _____ look the ____ in a given ____.
focus, same, lead
| p. 109
36
MAT is sometimes associated with...
...digitalis toxicity in patients with heart disease.
| p. 109
37
In MAT the atrial automaticity foci are ill, showing early signs of ___________ (entrance block) by developing a __________ to overdrive suppression. That is why no ______ _____ achieves pacemaking _________, so they all pace together.
```
parasystole
resistance
single focus
dominance
(p. 109)
```
38
Because of the multifocal origin of MAT, each individual atrial focus paces at ___ ___ ________ ____, but the total, combined pacing of multiple ____________ foci produces a _____, _________ rhythm.
its own inherent rate
unsuppressed
rapid, irregular
(p. 109)
39
Atrial fibrillation is caused by the continuous _____-______ of multiple ______ _____________ ____. No single impulse depolarizes the atria completely, and only an __________, ______ atrial depolarization reaches the __ ____ to be conducted to the ventricles; this produces an _________ ___________ rhythm.
```
rapid-firing
atrial automaticity foci
occasional, random
AV Node
irregular ventricular
(p. 110)
```
40
Atrial fibrillation is also the result of multiple "_________" ______ ____, suffering from entrance block, pacing rapidly. These multiple atrial foci are parasystolic, therefore they all pace at once.
"irritable" atrial foci
| p. 110
41
During atrial fibrillation, so single impulse __________ ___________ both atria, so there are no P waves, just a rapid series of tiny, erratic spikes on EKG.
completely depolarizes
| p. 110
42
When analyzing a strip, discernible P or P' waves rules out...
...atrial fibrillation
| p. 111
43
If the P waves are not identical, we know it is not a...
...sinus arrhythmia.
| p. 111
44
What is an escape rhythm?
The rhythm that occurs when an automaticity focus escapes overdrive suppression to pace at its inherent rate.
(p. 112)
45
What is an escape beat?
A beat that occurs when an automaticity focus transiently escapes overdrive suppression to emit one beat.
(p. 112)
46
What are the 3 types of escape rhythms?
atrial escape rhythms
junctional escape rhythms
ventricular escape rhythms
(p. 112)
47
What are the 3 types of escape beats?
atrial escape beat
junctional escape beat
ventricular escape beat
(p. 112)
48
"Escape" describes the ________ of an automaticity focus to a _____ in the ___________ activity.
response, pause, pacemaking
| p. 112
49
The SA Node's regular pacing overdrive-suppresses all automaticity foci, but a brief pause in SA Node pacing permits...
...an automaticity focus to escape overdrive suppression.
| p. 112
50
When the SA Node stops working, an automaticity focus with the _______ ________ ____ escapes to become the ______ _________.
fastest inherent rate
active pacemaker
(p. 113)
51
An automaticity focus is overdrive-suppressed if it is _________ ___________ __ _ ______ ____ ______ than its own inherent pacing rate.
regularly depolarized by a pacing rate faster
| p. 113
52
An automaticity focus esapes to emit an Escape Beat, which actually represents the first beat of the _______ by the focus to pace, but the return of SA Node pacing _________-__________ it again.
attempt
overdrive-suppresses
(p. 113)
53
An atrial escape rhythm should have a rate of...
The atrial escape rhythm should be ______ ____ the previous Sinus rate.
...60 - 80 beats per minute.
| slower than
p. 114
54
An Atrial Escape Rhythm originates in an atrial automaticity focus, so the P' waves are not _________ to the previous P waves that were produced by the __ ____.
identical
SA Node
(p. 114)
55
An Atrial Escape Rhythm occurs when an ______ _____ assumes ______ ______________ in the absence of _____ ______.
atrial focus
pacing responsibility
sinus rhythm
(p. 114)
56
If all other pacing stimuli above cease, an automaticity focus in the AV Junction may produce a _________ ______ ______ with a rate in the range of __ to __ beats/min.
junctional escape rhythm, 40 - 60
| p. 115
57
A junctional rhythm will also occur if there is a ________ __________ block in the ________ ___ of the AV Node.
complete conduction
proximal end
(p. 115)
58
Another term for junctional escape rhythm is...
...idiojunctional rhythm
| p. 115
59
Sometimes the inherent junctional pacing rhythm may speed up beyond its usual range to produce an...
...accelerated idiojunctional rhythm.
| p. 115
60
A junctional automaticity focus may cause __________ ______ ______________, recognizable by an ________ P' wave (in those leads that have an _______ QRS)
retrograde atrial depolarization
inverted
upright
(p. 116)
61
The AV Node conducts very slowly, so depolarization from a Junctional focus may delay EITHER ___________ depolarization or __________ ______ depolarization (if present)...
... as a result, if there is retrograde atrial depolarization from a junctional focus, it may record on EKG with one of these 3 patterns:
--retrograde (inverted) P' wave ___________ ______ ____ ___
--retrograde (inverted) P' wave _____ ____ ___
--retrograde (inverted) P' wave ______ ______ ____ ___
ventricular
retrograde atrial
immediately before each QRS
after each QRS
buried within each QRS
(p. 116)
62
A ventricular escape rhythm emerges with an inherent rate in the range of __ to __ beats/min.
20 - 40
| p. 117
63
With complete conduction block high in the ventricular conduction system (but below the AV Node), the ventricular foci are not __________ by atrial depolarizations from _____, so a ventricular focus escapes to pace the ventricles at its inherent rate.
stimulated
above
(p. 117)
64
Total failure of the SA Node and all automaticity foci above the ventricles is a rare and grave condition called "________ ____________ __ ___ _________". In extremis, a ventricular focus escapes to become the active ventricular pacemaker in a final, futile attempt to sustain life.
"downward displacement of the pacemaker"
| p. 117
65
Pacing from a ventricular focus is often so slow that blood flow to the brain is significantly reduced to the point of unconsciousness (_______). This is called ______-_____ ________. This unconscious patient requires an ______!
syncope
Stokes-Adams Syndrome
airway
(p. 117)
66
Should a ventricular rhythm speed up above the inherent rate range, it becomes an...
...accelerated idioventricular rhythm.
| p. 117
67
With a transient Sinus _____, an unhealthy SA node misses one pacing ________. This missed cycle produces a _____ during which the heart is electrically silent.
Block
stimulus
pause
(p. 118)
68
If there is a "sufficient" pause -- longer than the inherent pacing _____ ______ of an automaticity focus -- that focus will "escape" the SA Node's overdrive suppression to emit a ________.
cycle length
stimulus
(p. 118)
69
When an atrial escape beat occurs, the P' wave _______ from the _____-_________ P waves.
differs
sinus-generated
(p. 119)
70
If the SA node misses a cycle, and none of the atrial foci respond, a __________ automaticity focus will escape to emit a __________ ______ ____.
junctional
junctional escape beat
(p. 120)
71
A single Junctional Escape Beat may produce __________ atrial depolarization that records an inverted P' immediately ______ the QRS or an inverted P' _____ the QRS.
retrograde
before
after
(p. 120)
72
A ventricular escape beat typically produces an...
...enormous QRS complex.
| p. 121
73
Cardiac parasympathetic innervation inhibits the __ ____, the ______ and the __________ foci, but not the ___________ foci. Therefore, a burst of excessive parasympathetic activity depresses all of those foci, leaving only the ventricular foci to _______ to the _____. Such a burst of parasympathetic activity is usually _________, so the SA Node resumes its pacemaking activity.
SA Node, atrial, junctional, ventricular
respond, pause
transient
(p. 121)
74
A premature beat occurs when an _________ _____ spontaneously fires a ______ stimulus.
irritable focus, single
| p. 122
75
___________ automaticity foci are the most sensitive __ sensors. When they sense ___ __, they become irritable, and they react!!
Ventricular, O2, low O2
| p. 122
76
Premature beats can cause _____________ in the rhythm that may _____ more serious problems such as ____________ __________ _____.
peculiarities, mimic,
pathological conduction blocks
(p. 122)
77
Atrial and Junctional foci become irritable for a number of reasons. Name 8.
1) adrenaline (epinephrine) released by adrenal glands
2) increased sympathetic stimulation, or decrease in parasympathetic stimulation
3) caffeine, amphetamines, cocaine, or other beta1 receptor stimulants
4) excess digitalis and some toxins
5) occasionally ethanol
6) hyperthyroidism (this causes direct stimulation plus the heart is oversensitive to adrenergic stimulants)
7) stretch
8) to some extent, low O2
(p. 123)
78
A VERY irritable atrial or junctional focus may fire a series of rapid pacing impulses to become the ________ _________, overdrive-suppressing all automaticity centers.
```
dominant pacemaker
(p. 123)
```
79
Which is more prone to getting irritable from conditions/substances, atrial or junctional foci?
Atrial
| p. 123
80
How can you recognize a premature atrial beat on EKG?
It produces a P' wave earlier than expected.
| p. 124
81
On EKG, a PAB records as a P'. The P' may be difficult to detect when it's hiding on the peak of a T wave; the giveaway is a ___-____ T wave, ______ than the other T waves in the same lead.
too-tall, taller
82
Atrial depolarization from a focus near the SA Node produces a generally _______ __ wave, whereas a focus in the _____ ______ depolarizes the atria in a "______-_______" (__________) fashion to record an inverted __ wave in most leads.
```
upright P'
lower atrium
bottom-upwards (retrograde)
P'
(p. 124)
```
83
An active automaticity center "______" to continue pacing ___ _____ ______ from a ________ ________.
In other words, a center of automaticity (SA Node included) resets its rhythm when it is ___________ by a premature stimulus, so its pacemaking activity resets __ ____ with the _________ ____.
"resets", one cycle length, premature stimulus
depolarized, in step, premature beat
(p. 125)
84
In order to reset, the dominant (active) center of automaticity must be depolarized by the premature beat. When there is a premature stimulus that does ___ _____ the dominant pacing center, its pacing is ___ _____.
not reach
not reset
(p. 125)
85
A PAB produces a too-early depolarization of the atria that depolarizes the __ ____ as well. The __ ____ will reset its rhythm in step with the PAB (P').
SA Node
SA Node
(p. 126)
86
Will a premature atrial beat still produce a normal QRS?
yes
| p. 126
87
The pacing rate of the SA Node before and after the PAB _______ ___ ____.
That said, it reality the first cycle after a PAB/PAC is a little __________ due to a transient (baroreceptor) _______________ effect on the SA Node, which resumes pacing during systole.
remains the same
lengthened
parasympathetic
(p. 126)
88
The ventricular conduction system is usually _________ to being depolarized by a PAB/PAC, but one Bundle Branch may not have completely ___________ when the other is receptive. (That is, it's still a little __________.) This ________ ___________ __________ produces a slightly _______ QRS for that premature cycle only.
```
receptive
repolarized
refractory
aberrant ventricular contraction
widened
(p. 127)
```
89
Remember that, the non-___________ depolarization of the ventricles records as a slightly _______ QRS complex.
simultaneous
widened
(p. 127)
90
A PAB/PAC may be unable to depolarize the AV Node if it is not fully ___________ and still __________ to an extra ________.
repolarized
refractory
stimulus
(p. 128)
91
A non-conducted PAB/PAC records as a too-early, unusual __ wave that has no ___________ response.
P'
ventricular
(p. 128)
92
Although a non-conducted PAB/PAC does not depolarize the ventricles, it DOES depolarize the __ ____, which ______ its pacemaking one cycle length after the premature stimulus.
The combination of reset pacing plus the missing QRS-T creates a harmless, but dangerous-looking ____ __ _____ ________, which has the sinister appearance of "some kind of _____".
SA Node, resets
span of empty baseline
block
(p. 128)
93
When an irritable atrial focus repeatedly couples a PAB/PAC to the end of each (otherwise normal) cycle, this is a run of _____ ________
Atrial Bigeminy
| p. 129
94
```
The cycle containing the premature beat together with the _____ or ______ to which it _______, is called a "_______".
A series ("run") of couplet groups called "_____ _______" is often seen with Atrial Bigeminy, Atrial Trigeminy, etc.
```
cycle, cycles, couples, couplet
"group beating"
(p. 129)
95
Notice also that a run of atrial trigeminy or bigeminy may also have a widened (aberrant) ___ after each __ in the tracing.
________ ___________ __________ can occur after any premature atrial or junctional beat.
QRS, P'
aberrant ventricular contraction
(p. 129)
96
A premature junctional beat (PJB/PJC) occurs when an irritable automaticity focus in the __ ________ suddenly fires a premature stimulus that is conducted to, and depolarizes, the ventricles, and sometimes the _____, in __________ fashion.
AV Junction
atria
retrograde
(p. 131)
97
If you see a premature QRS complex that is slightly widened, you should consider that it may be due to a _________ __________ __ ______ ____ with aberrant ventricular conduction.
premature junctional or atrial beat
| p. 131
98
A junctional automaticity focus may cause __________ atrial depolarization.
retrograde
| p. 132
99
Since atrial and ventricular depolarization move in ________ directions from the Junctional Focus, the premature __ wave is ________ the direction of the QRS.
opposite
P'
opposite
(p. 132)
100
Just as with retrograde atrial depolarization, with a PJB, sometimes the P' wave follows the QRS, but the P' wave can also ____________ __________ within the QRS when atrial and ventricular depolarization occur ______________.
occasionally disappear
simultaneously
(p. 132)
101
Retrograde atrial depolarization from a PJB/PJC usually depolarizes the __ ____ as well. So the SA Node pacing is _____ in step with the retrograde ______ depolarization.
SA Node
reset
atrial
(p. 132)
102
An irritable junctional automaticity focus may fire a _________ stimulus coupled to the end of each normal cycle to produce __________ ________.
premature
junctional bigeminy
(p. 133)
103
An irritable junctional automaticity focus may fire a stimulus after two consecutive, normal cycles. A repeating series of these ________ is known as __________ _________.
couplets
junctional TRIgeminy
(p. 133)
104
Don't forget that on EKG you may see an ________ retrograde __ wave with every PJB in either bigeminy or trigeminy. Also the SA Node will reset its pacing with each retrograde atrial depolarization; this can produce ________ (but innocent) gaps of _____ ________ between couplets.
```
inverted
P'
alarming
empty baseline
(p. 133)
```
105
A ventricular focus can be made irritable by a number of things. Name 4 main reasons and list examples.
3 Big Reasons, 1 little reason: hypoxia, low K+, pathology (such as mitral valve prolapse, stretch, myocarditis, QT-prolongation), and to a lesser degree, beta1 stimulants (especially cocaine)
Now, there's a long list under hypoxia, but examples include anything that limits oxygen delivery to the heart muscle:
1) airway obstruction
2) near-drowning
3) suffocation
4) low O2 content in air
5) PE
6) pneumothorax
7) reduced cardiac output from hypovolemic shock, cardiogenic shock, or any other kind of shock
8) Coronary insufficiency or infarction
(p. 134)
106
Why is cocaine especially capable of evoking irritability in the heart?
It is known to irritate atrial and junctional foci, but it also causes coronary vasospasm, making ventricular foci hypoxic and thus, irritable
(p. 134)
107
PVC may stand for...
...premature ventricular complex or premature ventricular contraction
(p. 135)
108
PVC's occur early in the _____. They are usually ________ the polarity of the normal QRS's.
cycle
opposite
(p. 135)
109
What is the most likely reason for a ventricular automaticity focus to become irritable?
HYPOXIA
| p. 135
110
Why do PVC's result in a weaker pulse beat?
Because the prematurely stimulated ventricles are not completely filled.
(p. 135)
111
When an irritable ventricular automaticity focus suddenly fires an impulse, that ______ depolarizes before the rest of the ventricle, and then the depolarization wave creeps to the other ventricle which depolarizes, producing an enormously ____ ventricular complex. In contrast, a normal depolarization would pass through the entire thickness of ____ __________ at once.
region
wide
both ventricles
(p. 136)
112
The reason a normal QRS is shorter and more slender than a PVC is that left ventricular depolarization in the leftward direction tends to be _______________ by the simultaneous right ventricular depolarization in the opposite direction. This _________ the QRS _________.
counterbalanced
minimizes
amplitude
(p. 136)
113
PVC's depolarize only the __________, not the __ ____, so the __ ____ still discharges on ________. In fact, by measuring P-P cycles, you can often locate the ________ _ ____ within a PVC.
```
ventricles
SA Node
SA Node, schedule
punctual P wave
(p. 137)
```
114
That punctual P wave following a PVC occurs while the ventricles are still __________. When the normal stimulus arrives, they can't depolarize, so there is a _____ as the ventricles finish ____________, making them receptive to the next _____-_________ cycle.
```
refractory
pause
repolarizing
sinus-generated
(p. 137)
```
115
____________ PVC's are rare, but are somehow sandwiched between the beats of a normal rhythm, producing no _____ and no ______ ___________.
Interpolated
pause
rhythm disturbance
(p. 137)
116
___ or ____ PVC's per minute is considered pathological.
6 or more
| p. 138
117
________ PVC's all originate from the same irritable focus.
Unifocal
| p. 138
118
Ventricular automaticity foci are the heart's _______ early _______ system. _______!
hypoxia, warning
Respond!
(p. 139)
119
Ventricular __________ is produced by a ventricular automaticity focus that suffers from ________ block (but is not irritable). The parasystolic focus is not vulnerable to _________-___________, so it paces at its inherent rate, and the ventricular complexes that it generates poke through the dominant _____ ______.
```
parasystole
entrance
overdrive-suppression
Sinus Rhythm
(p. 140)
```
120
When you see PVC's that appear to be coupled to a ____ ______ of normal cycles, you should suspect ___________ ___________.
long series
Ventricular Parasystole
(p. 140)
121
In Ventricular Parasystole, recognize that you are seeing two _________, independent rhythms, so the ________ between the normal cycle and large ventricular complex is not always consistent.
Occasionally, a large ventricular complex may fail to appear because the ventricular focus happens to discharge during the __________ period of the sinus-paced ventricles.
unrelated
interval
refractory
(p. 140)
122
A run of three or more PVC's is really a run of ___________ ___________ (__). If the run lasts longer than __ _______, it is called "_________" __.
Ventricular tachycardia (VT)
30 seconds
"sustained" VT
(p. 141)
123
In cardiac infarction, severe cardiac hypoxia can cause __________ PVC's, which increases the chance of developing a ______ arrhythmia.
mulitfocal
deadly
(p. 142)
124
Mitral valve prolapse (MVP), also known as _____ ________, can causes runs of __ and __________ ____, yet it is considered a ______ condition.
With MVP, the mitral valve is "______" and billows into the ____ ______ during ventricular systole.
Barlow syndrome, VT, multifocal PVC's, benign
"floppy", left atrium
(p. 143)
125
MVP is quite common; it occurs in ___ to ____ of females, and about ____ of males.
Females with MVP typically have a _______ body with a slight chest _________, experience "_____" spells, and are _______-_____. They first experience symptoms after age __.
```
6% to 17%
1.5%
slender, deformity, "dizzy", anxiety-prone
20
(p. 143)
```
126
In people with MVP, the billowing valves pull on the _______ that tether them to the _________ muscles in the left ventricle. This traction can cause localized _______ and ________, irritating adjacent ___________ ____________ ____.
```
chordae
papillary
stretch and ischemia
ventricular automaticity foci
(p. 143)
```
127
MVP patients usually have a ___-________ _____ with a ___________ murmur on auscultation.
mid-systolic click
decrescendo
(p. 143)
128
If a PVC falls on a _ ____, it may cause _ on _ phenomenon. This is of particular concern in situations of _______ or ____________; this phenomenon occurs during a __________ period, and dangerous arrhythmias may result.
T wave; R-on-T
hypoxia, hypokalemia; vulnerable
(p. 144)
129
What is a tachyarrhythmia?
A rapid rhythm originating in very irritable automaticity foci.
(p. 146)
130
A paroxysmal tachycardia occurs when a very irritable automaticity focus suddenly paces rapidly, in the range of ___ to ___ beats/min.
The 3 types are:
```
150 – 250
Paroxysmal atrial tachycardia
Paroxysmal junctional tachycardia
Paroxysmal ventricular tachycardia
(p. 147)
```
131
Once you recognize a paroxysmal tachycardia, you need only…
…identify the focus of origin – either atrial, junctional, or ventricular.
(p. 147)
132
Generally speaking, stimulants make ______ _____ ____ irritable, whereas more threatening physiological conditions like _______ make ventricular foci irritable.
In addition, a single premature stimulus from _______ _____ can provoke an irritable focus into a run of paroxysmal __________.
```
higher level foci
hypoxia
another focus
tachycardia
(p. 147)
```
133
In contrast to a paroxysmal tachycardia, sinus tach is the SA Node’s _______ response to exercise, excitement, etc. Although it may become quite rapid, it is neither ______ nor does it originate in an ____________ _____.
Gradual
Sudden
Automaticity focus
(p. 147)
134
While the rate range of paroxysmal tachycardia is defined as 150 – 250 in this book, some authors now set the lower limit of paroxysmal tachycardia at…
…125 per minute
| p. 148
135
Paroxysmal atria tachycardia (PAT) is caused by the sudden, rapid firing of a very irritable ______ automaticity focus. Because the origin is atrial, the atrial depolarizations of PAT are __ waves that do not look like sinus-generated ones.
Atrial
P’
(p. 149)
136
Paroxysmal atrial tachycardia with AV block has more than one __ wave spike for every ___. Suspect _________ ______ or ________.
P’, QRS
digitalis excess or toxicity
(p. 150)
137
Digitalis can provoke an atrial focus to suddenly pace very rapidly, but at the same time, it markedly ________ the AV Node, so that only every ______ stimulus conducts to the ventricles.
inhibits, second
| p. 150
138
Paroxysmal Junctional Tachycardia is caused by the sudden rapid pacing of a very irritable focus in the __ ________ that paces at a rate of ___ to ___ per minute.
AV Junction, 150 – 250 per minute
| p. 151
139
Just as with a PJB/ PJC, Paroxysmal Junctional Tachycardia (PJT) may also depolarize the atria from below in a retrograde fashion to record an ________ __ immediately ______ each upright QRS, or _____ each upright QRS, or ______ ______ each QRS.
Inverted P’, before, after, buried within
| p. 151
140
Don’t forget that with paroxysmal junctional tachycardia (PJT), the left and right bundle branches may not depolarize simultaneously, resulting in ________ ___________ __________.
Aberrant ventricular conduction
| p. 151
141
Another type of Junctional Tachycardia is called __ _____ _______ ___________.
AV Nodal Reentry Tachycardia
| p. 152
142
A theoretical “reentry circuit” may continuously circle (like perpetual motion) through the AV Junctional region, giving off a depolarization stimulus to the _____ and to the __________ with each pass in the circuit. This rhythm looks suspiciously like ___.
atria
ventricles
PJT (paroxysmal junctional tachycardia)
(p. 152).
143
Only ________ ________ of the coronary sinus region can successfully eliminate AV Nodal Reentry Tachycardia.
Catheter ablation
| p. 152
144
The very irritable foci that produce both paroxysmal atrial and junctional tachycardias originate above the ventricles, so these arrhythmias are known as __________ ________________ ___________.
Paroxysmal Supraventricular Tachycardia
| p. 153
145
SVT, or supraventricular tachycardia (the word “paroxysmal” is often omitted), is a general term which includes both…
…paroxysmal atrial tachycardia and paroxysmal junctional tachycardia.
(p. 153)
146
Paroxysmal atrial tachycardia can be so rapid that all __ waves run into the preceding _ waves to become indistinguishable. This can make differentiation between PAT and PJT very difficult.
But… since treatment for both is so similar, the umbrella term “SVT” suffices.
P’, T
| p. 153
147
Paroxysmal Ventricular Tachycardia (or just VT) is produced by a very irritable ventricular automaticity focus that suddenly paces in the ___ to ___ per minute range. During VT, the SA Node still paces the _____, but the large, dramatic ventricular complexes hide the individual P waves that can be seen only occasionally. So, there is independent pacing of the atria and the ventricles… a type of __ ____________.
150 to 250
Atria
AV dissociation
(p. 154)
148
On occasion during VT, a (sinus-paced) depolarization stimulus from the atria finds the entire ventricular conduction system _________ to depolarization and produces a normal-appearing ___ (_______ beat) in the midst of the VT.
More commonly during VT, an atrial depolarization finds a receptive __ ____, but ventricular depolarization only proceeds so far before it meets ventricular depolarization progressing from the ___________ _____. This produces a ______ beat, which is a blend on EKG of a normal QRS with a ___-like complex.
receptive
QRS (capture
```
AV Node
ventricular focus
fusion
PVC
(p. 155)
```
149
The presence of "________" or "_______" confirms the diagnosis of VT, because they could not occur during ___.
captures or fusions
SVT
(p. 155)
150
Paroxysmal VT often indicates...
...poor oxygenation of the heart.
| p. 156
151
The rapid rate of VT is too fast for the heart to ________ ___________, particularly in the elderly with compromised __________.
function effectively
coronaries
(p. 156)
152
A rapid junctional or atrial SVT with ________ conduction can produce a tachycardia with widened QRS's that ______ VT. You must differentiate the two because you should _____ give medications for ___ to a patient with VT.
```
aberrant
mimics
NEVER
SVT
(p. 156)
```
153
The QRS width in SVT, even if widened by aberrant ventricular conduction, is usually ____ sec or less in duration.
0. 14 sec
| p. 157
154
Which arrhythmia are patients with coronary insufficiency more likely to develop? Wide QRS SVT or VT?
VT
| p. 157
155
The QRS width in VT is usually...
...greater than 0.14 sec in duration.
| p. 157
156
Which arrhythmia is more likely to have AV dissociation showing captures or fusions? Wide QRS SVT or VT?
VT
| p. 157
157
What other characteristic is common in VT that is not common in wide QRS SVT?
extreme right axis deviation
| p. 157
158
Torsades de Pointes is caused by __ _________, medications that _____ _________ ________, or congenital abnormalities (i. e. ___ __ syndrome), all of which lengthen the QT segment.
```
low potassium, block potassium channels
long QT
(p. 158)
```
159
Torsades de Pointes means...
..."twisting of points"
| p. 158
160
In atrial flutter an extremely irritable atrial automaticity focus fires at a rate of ___ to ___ per minute, producing a rapid series of ______ _______________.
250 - 350, atrial depolarizations
| p. 159
161
In atrial flutter, the __ ____ has a long ___________ period, so only ___ in a series of flutter waves conducts to the __________.
AV Node, refractory, one, ventricles
| p. 159
162
Most commonly in a flutter, only one of _____ atrial stimuli results in ventricular depolarization.
three
| p. 159
163
_________ a tracing of suspected atrial flutter can help in is ______________.
Inverting, identification
| p. 160
164
Vagal maneuvers increase __ ____ ______________, allowing fewer flutter waves to be conducted to the ventricles. This produces a longer series of _______ _____ that are easier to identify.
AV Node refractoriness
flutter waves
(p. 160)
165
The "Maze" surgical procedures cuts (and resutures) the atria into a maze of channels that provides a...
This procedure eliminates any possibility of _______ ________. Yet a study of patients recovering from the maze procedure, revealed that __% developed atrial flutter or fibrillation post-op. This raises considerable doubt that the origin of atrial flutter could be _______.
...continous pathway from the SA Node to the AV Node.
| reentry circuits
47%
reentry
p. 160
166
Ventricular Flutter is produced by a ______ ventricular automaticity focus firing at an exceptionally rapid rate of ___ to ___ per minute.
single
| 250 to 350
167
The distinguishing feature of ventricular flutter is the ______ ____-____ pattern.
smooth sine-wave
| p. 161
168
Ventricular flutter rarely ____-________ and is nearly always a prelude to a ______ __________.
self-resolves
deadly arrhythmia
(p. 161)
169
You know a rhythm is paroxysmal atrial tachycardia (PAT) without block when each __ wave produces a ___ ________. And you know it is atrial and not junctional because of the lack of...
P', QRS response
...inverted P' waves that are evidence of retrograde depolarizations.
(p. 163)
170
In all types of fibrillation, the irritable foci all suffer from ________ _____, so they are ____________.
The "rate" of ___ to ___ per minute is not a true rate, since many of the foci discharge ______________.
entrance block, parasystolic
350 - 450, simultaneously.
(p. 164)
171
Atrial fibrillation is caused by many ________ parasystolic atrial ____ firing at rapid rates, producing an exceedingly rapid, _______ atrial rhythm.
irritable
foci
erratic
(p. 165)
172
Atrial fibrillation is usually initiated by parasystolic foci in the _________ ____ _____ of the left atrium.
pulmonary vein ostia
| p. 165
173
With atrial fibrillation, the ventricular ____ depends on the AV Node's ________ of ______________ after it is stimulated.
rate, duration, refractoriness
| p. 166
174
Ventricular fibrillation (VF) is caused by rapid discharges from many irritable, ____________ ventricular automaticity foci, producing an erratic twitching of the ventricles at a rate of ___ to ___ per minute.
parasystolic
350 - 450
(p. 167)
175
In Wolff-Parkinson-White syndrome, an abnormal, _________ AV conduction pathway, the bundle of ____, can "_____ _______" the usual delay of ventricular conduction in the AV node. This prematurely depolarizes or "pre-_______" a portion of the ventricles, producing a _____ ____ on EKG just before normal ventricular depolarization begins.
accessory
Kent
short circuit
excites
delta wave
(p. 171)
176
The accessory ______ of ____ causes ventricular pre-excitation in _____-_________-_____ Syndrome.
Bundle Kent
Wolff-Parkinson-White
(p. 171)
177
The delta wave in WPW Syndrome creates the illusion of a _________ __ interval and __________ QRS. The delta wave actually records the depolarization of an area of ventricular pre-excitation.
shortened PR
lengthened QRS
(p. 171)
178
Patients with WPW syndrome can have paroxysmal tachycardia but three different mechanisms:
1. ) _____ __________ -- SVT (including atrial flutter or fib) may be rapidly conducted 1:1 through this accessory pathway producing ___________ high ___________ rates.
2. ) Some ____ Bundles have been found to contain ____________ ____ that can initiate a __________ ___________.
3. ) Re-entry -- ventricular depolarization may immediately ___________ the atria in a __________ fashion via the accessory pathway causing a theoretical ______ _______ loop.
rapid conduction, dangerously, ventricular
Kent, automaticity foci, paroxysmal tachycardia
restimulate, retrograde, circus re-entry
(p. 171)
179
In patients with ____-______-______ (LGL) Syndrome, the AV node is ________ by an extension of the ________ __________ Tract.
Without the conduction delay in the AV Node, this "_____ ______" conducts atrial depolarizations directly to the ___ ______ without delay. This can pose a serious problem with rapid atrial arrhythmias like ______ _______.
Lown-Ganong-Levine, bypassed, Anterior Internodal
James bundle (or tract), His Bundle
atrial flutter
(p. 172)
180
With LGL Syndrome, the AV Node is bypassed, so there is no significant __ ________ delay; the P waves are ________ to their QRS's on the EKG.
PR interval, adjacent
| p. 172
