Chapter 5: Rhythm, Part 1: Arrhythmias of Focal Origin

Question 1

Arrhythmia literally means…

Answer 1

…without rhythm.

p. 97

Question 2

All automaticity foci pace at a…

Answer 2

…regular rhythm.

p. 99

Question 3

In reality, a normal sinus rhythm varies _____________ with __________.

Answer 3

imperceptibly with respiration

p. 99

Question 4

Sinus arrhythmia is a normal but extremely _______ increase in _____ ____ during ___________, and an extremely minimal ________ in heart rate during __________.

Answer 4

minimal, heart rate, inspiration
decrease, expiration
(p. 100)

Question 5

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…

Answer 5

inspiration, sympathetic
expiration, parasympathetic

both divisions of the autonomic nervous system
(p. 100)

Question 6

A significant decrease in heart rate variability is actually…

Answer 6

…pathological and a valuable indicator of increased mortality.
(p. 100)

Question 7

The atrial conduction system consists of 3 specialized internodal tracts in the _____ ______, and 1 conduction tract that innervates the ____ ______.

Answer 7

right atrium
left atrium
(p. 101)

Question 8

What are the 3 internodal tracts in the right atrium?

Answer 8

the anterior, middle, and posterior

p. 101

Question 9

What is the conduction tract that innervates the left atrium?

Answer 9

Bachmann’s Bundle

p. 101

Question 10

Why are they referred to as internodal tracts?

Answer 10

Because they course from the SA node to the AV node. (p. 101)

Question 11

Bachmann’s Bundle originates in the __ ____ and distributes depolarization to the ____ ______.

Answer 11

SA Node
left atrium
(p. 101)

Question 12

Depolarization passing rapidly through the atrial conduction system does not ______ __ ___; however, depolarization of the ______ __________ produces a _ ____ on EKG.

Answer 12

record on EKG
atrial myocardium
P wave
(p. 101)

Question 13

Because there is a concentration of merging ______ __________ ______ in the immediate region of the __ ____ near the ________ _____, considerable automaticity activity originates in that area.

Answer 13

atrial conduction tracts
AV node
coronary sinus
(p. 101)

Question 14

The heart’s own venous drainage (i.e. from the __________) empties into the _____ ______ via the ________ _____.

Answer 14

myocardium
right atrium
coronary sinus
(p. 101)

Question 15

When the depolarization stimulus (passing down from the atria) reaches the __ ____, the stimulus _____ in the __ Node, producing a _____ __ ___.

Answer 15

AV Node, slows, AV, pause on EKG

p. 102

Question 16

Depolarization passing through the Purkinje fibers of the ventricular conduction system is ___ ____ to ______ __ ___; this is a form of “_________” __________.

Answer 16

too weak to record on EKG
“concealed” conduction
(p. 103)

Question 17

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.

Answer 17

rapidly, terminal Purkinje filaments, endocardial, ventricular
(p. 103)

Question 18

When the ___________ ___________ depolarizes, it produces a ___ _______ on EKG.

Answer 18

ventricular myocardium
QRS complex
(p. 103)

Question 19

Ventricular depolarization begins ______ down the ________________ ______, where the left bundle branch produces fine terminal filaments.

Answer 19

midway, interventricular septum

p. 104

Question 20

The right bundle branch does not _______ ________ _________ __ ___ ______.
As a result, ____-to-_____ depolarization of the septum occurs immediately before the rest of the ___________ __________ ___________.

Answer 20

produce terminal filaments in the septum.
left-to-right, ventricular myocardium depolarizes
(p. 104)

Question 21

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.

Answer 21

longer
ventricular repolarization, 
Purkinje fibers
small hump, U wave
(p. 104)

Question 22

A very _________ automaticity focus may suddenly pace _______.

Answer 22

irritable, rapidly

p. 105

Question 23

What are the 3 types of irregular (atrial) rhythms?

Answer 23

wandering pacemaker
multifocal atrial tachycardia
atrial fibrillation
(p. 107)

Question 24

Irregular (atrial) rhythms are usually caused by…

Answer 24

…multiple, active automaticity sites

p. 107

Question 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 ___________ _______.

Answer 25

entrance block
“protecting”
passive depolarization

cannot
overdrive-suppressed
conducted to surrounding tissue.
(p. 107)

Question 26

When an automaticity focus has entrance block, is it said to be ___________ (the focus _____, but can’t be _________-__________).

Answer 26

parasystolic
paces
overdrive-suppressed
(p. 107)

Question 27

Wandering pacemaker is an _________ rhythm produced by pacemaker activity “wandering” from the __ ____ to nearby ____________ ____.

Answer 27

irregular
SA node
automaticity foci
(p. 108)

Question 28

P’ is pronounced…

Answer 28

…“P prime”

p. 108

Question 29

What does P’ represent?

Answer 29

Atrial depolarization by an automaticity focus, as opposed to normal sinus-paced P waves.
(p. 108)

Question 30

In a given lead, each atrial automaticity focus produces its own…

Answer 30

…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)

Question 31

The 3 characteristics of a wandering pacemaker rhythm are:
P’ wave _____ ______
Atrial rate ____ ____ ___
_________ ___________ rhythm, thus the _____ lengths vary.

Answer 31

shape varies
less than 100
Irregular ventricular, cycle
(p. 108)

Question 32

Should a wandering pacemaker rate accelerate into a tachycardia, it becomes…

Answer 32

…multifocal atrial tachycardia.

p. 108

Question 33

Multifocal atrial tachycardia is a rhythm of patients with _______ ___________ _________ disease.

Answer 33

chronic obstructive pulmonary.

p. 109

Question 34

The heart rate in MAT is over ___ per minute with P’ waves of various shapes, since ____ or more ______ ____ are involved.

Answer 34

100
three
atrial foci
(p. 109)

Question 35

P’ waves from the same _____ look the ____ in a given ____.

Answer 35

focus, same, lead

p. 109

Question 36

MAT is sometimes associated with…

Answer 36

…digitalis toxicity in patients with heart disease.

p. 109

Question 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.

Answer 37

parasystole
resistance
single focus
dominance
(p. 109)

Question 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.

Answer 38

its own inherent rate
unsuppressed
rapid, irregular
(p. 109)

Question 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.

Answer 39

rapid-firing
atrial automaticity foci
occasional, random
AV Node 
irregular ventricular
(p. 110)

Question 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.

Answer 40

“irritable” atrial foci

p. 110

Question 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.

Answer 41

completely depolarizes

p. 110

Question 42

When analyzing a strip, discernible P or P’ waves rules out…

Answer 42

…atrial fibrillation

p. 111

Question 43

If the P waves are not identical, we know it is not a…

Answer 43

…sinus arrhythmia.

p. 111

Question 44

What is an escape rhythm?

Answer 44

The rhythm that occurs when an automaticity focus escapes overdrive suppression to pace at its inherent rate.
(p. 112)

Question 45

What is an escape beat?

Answer 45

A beat that occurs when an automaticity focus transiently escapes overdrive suppression to emit one beat.
(p. 112)

Question 46

What are the 3 types of escape rhythms?

Answer 46

atrial escape rhythms
junctional escape rhythms
ventricular escape rhythms
(p. 112)

Question 47

What are the 3 types of escape beats?

Answer 47

atrial escape beat
junctional escape beat
ventricular escape beat
(p. 112)

Question 48

“Escape” describes the ________ of an automaticity focus to a _____ in the ___________ activity.

Answer 48

response, pause, pacemaking

p. 112

Question 49

The SA Node’s regular pacing overdrive-suppresses all automaticity foci, but a brief pause in SA Node pacing permits…

Answer 49

…an automaticity focus to escape overdrive suppression.

p. 112

Question 50

When the SA Node stops working, an automaticity focus with the _______ ________ ____ escapes to become the ______ _________.

Answer 50

fastest inherent rate
active pacemaker
(p. 113)

Question 51

An automaticity focus is overdrive-suppressed if it is _________ ___________ __ _ ______ ____ ______ than its own inherent pacing rate.

Answer 51

regularly depolarized by a pacing rate faster

p. 113

Question 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.

Answer 52

attempt
overdrive-suppresses
(p. 113)

Question 53

An atrial escape rhythm should have a rate of…

The atrial escape rhythm should be ______ ____ the previous Sinus rate.

Answer 53

…60 - 80 beats per minute.

slower than
p. 114

Question 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 __ ____.

Answer 54

identical
SA Node
(p. 114)

Question 55

An Atrial Escape Rhythm occurs when an ______ _____ assumes ______ ______________ in the absence of _____ ______.

Answer 55

atrial focus
pacing responsibility
sinus rhythm
(p. 114)

Question 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.

Answer 56

junctional escape rhythm, 40 - 60

p. 115

Question 57

A junctional rhythm will also occur if there is a ________ __________ block in the ________ ___ of the AV Node.

Answer 57

complete conduction
proximal end
(p. 115)

Question 58

Another term for junctional escape rhythm is…

Answer 58

…idiojunctional rhythm

p. 115

Question 59

Sometimes the inherent junctional pacing rhythm may speed up beyond its usual range to produce an…

Answer 59

…accelerated idiojunctional rhythm.

p. 115

Question 60

A junctional automaticity focus may cause __________ ______ ______________, recognizable by an ________ P’ wave (in those leads that have an _______ QRS)

Answer 60

retrograde atrial depolarization
inverted
upright
(p. 116)

Question 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 ______ ______ ____ ___

Answer 61

ventricular
retrograde atrial

immediately before each QRS
after each QRS
buried within each QRS
(p. 116)

Question 62

A ventricular escape rhythm emerges with an inherent rate in the range of __ to __ beats/min.

Answer 62

20 - 40

p. 117

Question 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.

Answer 63

stimulated
above
(p. 117)

Question 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.

Answer 64

“downward displacement of the pacemaker”

p. 117

Question 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 ______!

Answer 65

syncope
Stokes-Adams Syndrome
airway
(p. 117)

Question 66

Should a ventricular rhythm speed up above the inherent rate range, it becomes an…

Answer 66

…accelerated idioventricular rhythm.

p. 117

Question 67

With a transient Sinus _____, an unhealthy SA node misses one pacing ________. This missed cycle produces a _____ during which the heart is electrically silent.

Answer 67

Block
stimulus
pause
(p. 118)

Question 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 ________.

Answer 68

cycle length
stimulus
(p. 118)

Question 69

When an atrial escape beat occurs, the P’ wave _______ from the _____-_________ P waves.

Answer 69

differs
sinus-generated
(p. 119)

Question 70

If the SA node misses a cycle, and none of the atrial foci respond, a __________ automaticity focus will escape to emit a __________ ______ ____.

Answer 70

junctional
junctional escape beat
(p. 120)

Question 71

A single Junctional Escape Beat may produce __________ atrial depolarization that records an inverted P’ immediately ______ the QRS or an inverted P’ _____ the QRS.

Answer 71

retrograde
before
after
(p. 120)

Question 72

A ventricular escape beat typically produces an…

Answer 72

…enormous QRS complex.

p. 121

Question 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.

Answer 73

SA Node, atrial, junctional, ventricular
respond, pause
transient
(p. 121)

Question 74

A premature beat occurs when an _________ _____ spontaneously fires a ______ stimulus.

Answer 74

irritable focus, single

p. 122

Question 75

___________ automaticity foci are the most sensitive __ sensors. When they sense ___ __, they become irritable, and they react!!

Answer 75

Ventricular, O2, low O2

p. 122

Question 76

Premature beats can cause _____________ in the rhythm that may _____ more serious problems such as ____________ __________ _____.

Answer 76

peculiarities, mimic,
pathological conduction blocks
(p. 122)

Question 77

Atrial and Junctional foci become irritable for a number of reasons. Name 8.

Answer 77

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)

Question 78

A VERY irritable atrial or junctional focus may fire a series of rapid pacing impulses to become the ________ _________, overdrive-suppressing all automaticity centers.

Answer 78

dominant pacemaker
(p. 123)

Question 79

Which is more prone to getting irritable from conditions/substances, atrial or junctional foci?

Answer 79

Atrial

p. 123

Question 80

How can you recognize a premature atrial beat on EKG?

Answer 80

It produces a P’ wave earlier than expected.

p. 124

Question 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.

Answer 81

too-tall, taller

Question 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.

Answer 82

upright P'
lower atrium
bottom-upwards (retrograde) 
P'
(p. 124)

Question 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 _________ ____.

Answer 83

“resets”, one cycle length, premature stimulus
depolarized, in step, premature beat

(p. 125)

Question 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 ___ _____.

Answer 84

not reach
not reset
(p. 125)

Question 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’).

Answer 85

SA Node
SA Node
(p. 126)

Question 86

Will a premature atrial beat still produce a normal QRS?

Answer 86

yes

p. 126

Question 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.

Answer 87

remains the same
lengthened
parasympathetic
(p. 126)

Question 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.

Answer 88

receptive
repolarized
refractory
aberrant ventricular contraction 
widened
(p. 127)

Question 89

Remember that, the non-___________ depolarization of the ventricles records as a slightly _______ QRS complex.

Answer 89

simultaneous
widened
(p. 127)

Question 90

A PAB/PAC may be unable to depolarize the AV Node if it is not fully ___________ and still __________ to an extra ________.

Answer 90

repolarized
refractory
stimulus
(p. 128)

Question 91

A non-conducted PAB/PAC records as a too-early, unusual __ wave that has no ___________ response.

Answer 91

P’
ventricular
(p. 128)

Question 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 _____”.

Answer 92

SA Node, resets
span of empty baseline
block
(p. 128)

Question 93

When an irritable atrial focus repeatedly couples a PAB/PAC to the end of each (otherwise normal) cycle, this is a run of _____ ________

Answer 93

Atrial Bigeminy

p. 129

Question 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.

Answer 94

cycle, cycles, couples, couplet
“group beating”
(p. 129)

Question 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.

Answer 95

QRS, P’
aberrant ventricular contraction
(p. 129)

Question 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.

Answer 96

AV Junction
atria
retrograde
(p. 131)

Question 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.

Answer 97

premature junctional or atrial beat

p. 131

Question 98

A junctional automaticity focus may cause __________ atrial depolarization.

Answer 98

retrograde

p. 132

Question 99

Since atrial and ventricular depolarization move in ________ directions from the Junctional Focus, the premature __ wave is ________ the direction of the QRS.

Answer 99

opposite
P’
opposite
(p. 132)

Question 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 ______________.

Answer 100

occasionally disappear
simultaneously
(p. 132)

Question 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.

Answer 101

SA Node
reset
atrial
(p. 132)

Question 102

An irritable junctional automaticity focus may fire a _________ stimulus coupled to the end of each normal cycle to produce __________ ________.

Answer 102

premature
junctional bigeminy
(p. 133)

Question 103

An irritable junctional automaticity focus may fire a stimulus after two consecutive, normal cycles. A repeating series of these ________ is known as __________ _________.

Answer 103

couplets
junctional TRIgeminy
(p. 133)

Question 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.

Answer 104

inverted
P'
alarming
empty baseline
(p. 133)

Question 105

A ventricular focus can be made irritable by a number of things. Name 4 main reasons and list examples.

Answer 105

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)

Question 106

Why is cocaine especially capable of evoking irritability in the heart?

Answer 106

It is known to irritate atrial and junctional foci, but it also causes coronary vasospasm, making ventricular foci hypoxic and thus, irritable
(p. 134)

Question 107

PVC may stand for…

Answer 107

…premature ventricular complex or premature ventricular contraction
(p. 135)

Question 108

PVC’s occur early in the _____. They are usually ________ the polarity of the normal QRS’s.

Answer 108

cycle
opposite
(p. 135)

Question 109

What is the most likely reason for a ventricular automaticity focus to become irritable?

Answer 109

HYPOXIA

p. 135

Question 110

Why do PVC’s result in a weaker pulse beat?

Answer 110

Because the prematurely stimulated ventricles are not completely filled.
(p. 135)

Question 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.

Answer 111

region
wide
both ventricles
(p. 136)

Question 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 _________.

Answer 112

counterbalanced
minimizes
amplitude
(p. 136)

Question 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.

Answer 113

ventricles
SA Node
SA Node, schedule
punctual P wave
(p. 137)

Question 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.

Answer 114

refractory
pause
repolarizing
sinus-generated
(p. 137)

Question 115

____________ PVC’s are rare, but are somehow sandwiched between the beats of a normal rhythm, producing no _____ and no ______ ___________.

Answer 115

Interpolated
pause
rhythm disturbance
(p. 137)

Question 116

___ or ____ PVC’s per minute is considered pathological.

Answer 116

6 or more

p. 138

Question 117

________ PVC’s all originate from the same irritable focus.

Answer 117

Unifocal

p. 138

Question 118

Ventricular automaticity foci are the heart’s _______ early _______ system. _______!

Answer 118

hypoxia, warning
Respond!
(p. 139)

Question 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 _____ ______.

Answer 119

parasystole
entrance
overdrive-suppression
Sinus Rhythm
(p. 140)

Question 120

When you see PVC’s that appear to be coupled to a ____ ______ of normal cycles, you should suspect ___________ ___________.

Answer 120

long series
Ventricular Parasystole
(p. 140)

Question 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.

Answer 121

unrelated
interval
refractory
(p. 140)

Question 122

A run of three or more PVC’s is really a run of ___________ ___________ (__). If the run lasts longer than __ _______, it is called “_________” __.

Answer 122

Ventricular tachycardia (VT)
30 seconds
“sustained” VT
(p. 141)

Question 123

In cardiac infarction, severe cardiac hypoxia can cause __________ PVC’s, which increases the chance of developing a ______ arrhythmia.

Answer 123

mulitfocal
deadly
(p. 142)

Question 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.

Answer 124

Barlow syndrome, VT, multifocal PVC’s, benign
“floppy”, left atrium
(p. 143)

Question 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 __.

Answer 125

6% to 17%
1.5% 
slender, deformity, "dizzy", anxiety-prone
20
(p. 143)

Question 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 ___________ ____________ ____.

Answer 126

chordae
papillary
stretch and ischemia
ventricular automaticity foci
(p. 143)

Question 127

MVP patients usually have a ___-________ _____ with a ___________ murmur on auscultation.

Answer 127

mid-systolic click
decrescendo
(p. 143)

Question 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.

Answer 128

T wave; R-on-T
hypoxia, hypokalemia; vulnerable
(p. 144)

Question 129

What is a tachyarrhythmia?

Answer 129

A rapid rhythm originating in very irritable automaticity foci.
(p. 146)

Question 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:

Answer 130

150 – 250
Paroxysmal atrial tachycardia
Paroxysmal junctional tachycardia
Paroxysmal ventricular tachycardia
(p. 147)

Question 131

Once you recognize a paroxysmal tachycardia, you need only…

Answer 131

…identify the focus of origin – either atrial, junctional, or ventricular.
(p. 147)

Question 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 __________.

Answer 132

higher level foci
hypoxia
another focus
tachycardia
(p. 147)

Question 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 ____________ _____.

Answer 133

Gradual
Sudden
Automaticity focus
(p. 147)

Question 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…

Answer 134

…125 per minute

p. 148

Question 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.

Answer 135

Atrial
P’
(p. 149)

Question 136

Paroxysmal atrial tachycardia with AV block has more than one __ wave spike for every ___. Suspect _________ ______ or ________.

Answer 136

P’, QRS
digitalis excess or toxicity
(p. 150)

Question 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.

Answer 137

inhibits, second

p. 150

Question 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.

Answer 138

AV Junction, 150 – 250 per minute

p. 151

Question 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.

Answer 139

Inverted P’, before, after, buried within

p. 151

Question 140

Don’t forget that with paroxysmal junctional tachycardia (PJT), the left and right bundle branches may not depolarize simultaneously, resulting in ________ ___________ __________.

Answer 140

Aberrant ventricular conduction

p. 151

Question 141

Another type of Junctional Tachycardia is called __ _____ _______ ___________.

Answer 141

AV Nodal Reentry Tachycardia

p. 152

Question 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 ___.

Answer 142

atria
ventricles
PJT (paroxysmal junctional tachycardia)
(p. 152).

Question 143

Only ________ ________ of the coronary sinus region can successfully eliminate AV Nodal Reentry Tachycardia.

Answer 143

Catheter ablation

p. 152

Question 144

The very irritable foci that produce both paroxysmal atrial and junctional tachycardias originate above the ventricles, so these arrhythmias are known as __________ ________________ ___________.

Answer 144

Paroxysmal Supraventricular Tachycardia

p. 153

Question 145

SVT, or supraventricular tachycardia (the word “paroxysmal” is often omitted), is a general term which includes both…

Answer 145

…paroxysmal atrial tachycardia and paroxysmal junctional tachycardia.
(p. 153)

Question 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.

Answer 146

P’, T

p. 153

Question 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 __ ____________.

Answer 147

150 to 250
Atria
AV dissociation
(p. 154)

Question 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.

Answer 148

receptive
QRS (capture

AV Node
ventricular focus
fusion
PVC
(p. 155)

Question 149

The presence of “________” or “_______” confirms the diagnosis of VT, because they could not occur during ___.

Answer 149

captures or fusions
SVT
(p. 155)

Question 150

Paroxysmal VT often indicates…

Answer 150

…poor oxygenation of the heart.

p. 156

Question 151

The rapid rate of VT is too fast for the heart to ________ ___________, particularly in the elderly with compromised __________.

Answer 151

function effectively
coronaries
(p. 156)

Question 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.

Answer 152

aberrant
mimics
NEVER
SVT
(p. 156)

Question 153

The QRS width in SVT, even if widened by aberrant ventricular conduction, is usually ____ sec or less in duration.

Answer 153

0. 14 sec

p. 157

Question 154

Which arrhythmia are patients with coronary insufficiency more likely to develop? Wide QRS SVT or VT?

Answer 154

VT

p. 157

Question 155

The QRS width in VT is usually…

Answer 155

…greater than 0.14 sec in duration.

p. 157

Question 156

Which arrhythmia is more likely to have AV dissociation showing captures or fusions? Wide QRS SVT or VT?

Answer 156

VT

p. 157

Question 157

What other characteristic is common in VT that is not common in wide QRS SVT?

Answer 157

extreme right axis deviation

p. 157

Question 158

Torsades de Pointes is caused by __ _________, medications that _____ _________ ________, or congenital abnormalities (i. e. ___ __ syndrome), all of which lengthen the QT segment.

Answer 158

low potassium, block potassium channels
long QT
(p. 158)

Question 159

Torsades de Pointes means…

Answer 159

…“twisting of points”

p. 158

Question 160

In atrial flutter an extremely irritable atrial automaticity focus fires at a rate of ___ to ___ per minute, producing a rapid series of ______ _______________.

Answer 160

250 - 350, atrial depolarizations

p. 159

Question 161

In atrial flutter, the __ ____ has a long ___________ period, so only ___ in a series of flutter waves conducts to the __________.

Answer 161

AV Node, refractory, one, ventricles

p. 159

Question 162

Most commonly in a flutter, only one of _____ atrial stimuli results in ventricular depolarization.

Answer 162

three

p. 159

Question 163

_________ a tracing of suspected atrial flutter can help in is ______________.

Answer 163

Inverting, identification

p. 160

Question 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.

Answer 164

AV Node refractoriness
flutter waves
(p. 160)

Question 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 _______.

Answer 165

…continous pathway from the SA Node to the AV Node.

reentry circuits
47%
reentry
p. 160

Question 166

Ventricular Flutter is produced by a ______ ventricular automaticity focus firing at an exceptionally rapid rate of ___ to ___ per minute.

Answer 166

single

250 to 350

Question 167

The distinguishing feature of ventricular flutter is the ______ ____-____ pattern.

Answer 167

smooth sine-wave

p. 161

Question 168

Ventricular flutter rarely ____-________ and is nearly always a prelude to a ______ __________.

Answer 168

self-resolves
deadly arrhythmia
(p. 161)

Question 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…

Answer 169

P’, QRS response
…inverted P’ waves that are evidence of retrograde depolarizations.
(p. 163)

Question 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 ______________.

Answer 170

entrance block, parasystolic
350 - 450, simultaneously.
(p. 164)

Question 171

Atrial fibrillation is caused by many ________ parasystolic atrial ____ firing at rapid rates, producing an exceedingly rapid, _______ atrial rhythm.

Answer 171

irritable
foci
erratic
(p. 165)

Question 172

Atrial fibrillation is usually initiated by parasystolic foci in the _________ ____ _____ of the left atrium.

Answer 172

pulmonary vein ostia

p. 165

Question 173

With atrial fibrillation, the ventricular ____ depends on the AV Node’s ________ of ______________ after it is stimulated.

Answer 173

rate, duration, refractoriness

p. 166

Question 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.

Answer 174

parasystolic
350 - 450
(p. 167)

Question 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.

Answer 175

accessory
Kent
short circuit

excites
delta wave
(p. 171)

Question 176

The accessory ______ of ____ causes ventricular pre-excitation in _____-_________-_____ Syndrome.

Answer 176

Bundle Kent
Wolff-Parkinson-White
(p. 171)

Question 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.

Answer 177

shortened PR
lengthened QRS
(p. 171)

Question 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.

Answer 178

rapid conduction, dangerously, ventricular

Kent, automaticity foci, paroxysmal tachycardia

restimulate, retrograde, circus re-entry
(p. 171)

Question 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 ______ _______.

Answer 179

Lown-Ganong-Levine, bypassed, Anterior Internodal
James bundle (or tract), His Bundle
atrial flutter
(p. 172)

Question 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.

Answer 180

PR interval, adjacent

p. 172