The AV node is made up of specialized cells located in
lower portion of the left atrium
upper portion of the right atrium
upper portion of the left atrium
lower portion of the right atrium
The delay of electrical impulses in the AV Node
allow the junction to contract
allow the atria to complete filling of ventricles before next contraction
makes the rate of discharge of SA node slower
forces electrical impulses to travel retroactively
makes pacemaker cells capable of discharging at a rhythmic rate of 40-60 bpm
The bundle of His
connects AV node with bundle branches
has pacemaker cells capable of discharging at rythmic rate of 30-50 bpm
activates atria in a backward (retrograde direction)
transmits impluses from the AV to the left atrium
A and C
AV Junction is comprised of
the AV node and branching portion of bundle of His
the AV node, branching, and nonbranching portion of bundle of His
the non branching portion of bundle of His
nonbranching portion, AV node, and purkinje fibers
the AV node, nonbranching portion, and His bundle
If the rate of discharge of SA node is slower than AV junction
the SA node has failed to discharge
the AV junction has failed to discharge
an impulse from the SA node has been conducted through the atria but not to the ventricles
the His junction has failed to generate an impulse
the AV junction must assume responsibility for conducting impulses to the atria
the AV node and nonbranching portion of the bundle of His may assume responsibility for pacing the heart
the AV junction may assume responsibility for pacing the heart if:
the AV node fails to discharge
the SA node fails to discharge
the rate of discharge of SA node is faster than AV junction
an impulse from the SA node is generated and conducted through the ventricles but not to the atria
the rate of discharge of SA node is slower than AV junction
an impulse from the SA node is generated and conducted through the atria but not to ventricles
B, E, and F
B, C and F
When the AV junction is pacing the heart
electrical implulse must travel in a forwards direction to activate ventricles
electrical impulse must travel in a backwards direction to activate ventricles
electrical impulse must travel in a backward direction to activate atria
electrical impulses must travel in a retrograde direction to activate ventricles
electrical impulses must travel in a retrograde direction to activate ventricles and atria
When an AV junction has assumed responsibility for pacing the heart, the P wave may appear
before QRS complex
after QRS complex
during QRS complex
before or during QRS complex
during or after QRS complex
before, during or after QRS complex
a QRS of <0.12 seconds
is usually indicative of a premature junctional complex
is always followed by a non-compensatory (incomplete pause)
is fast
We can recognize a PJC
because it arises from irritable site within the SA junction
it fires before its next expected sinus beat
QRS is usually <0.21 sec
often followed by a non-compensatory pause
A and B
B and D
A, B and D
The PJC replaces normal beats
The ability to recognize a PJC wave include all of the following symptoms except;
a P wave, QRS <0.12 sec, a non-compensatory (incomplete) pause, rate within normal ranges
a P wave may/may not be present, regular heart rhythm with premature beats
QRS <0.12 sec unless aberrantly conducted or an intraventricular conduction delay exists
P waves may occur before, during, or after QRS, rate usually within normal range, regular rhythm with premature beats
In a PJC, heart rates are usually...
within normal range, but depends on underlying rhythm
outside of normal range, but depends on underlying rhythm
within normal range, but depends on medical history
outside of normal range, but depends on whether or not the PJC arises from an irritable site
When trying to recognize a PJC, the rhythm should be
regular, but depends on the QRS
above average, with premature beats
regular, with premature beats
To recognize a PJC, we should look at...
rate, rhythm, QRS and PRI
rhythm, QRS, P waves and PRI
rate, QRS, PRI, rhythm and P waves
QRS, P waves, ectopic beats, underlying rhythm
rhythm, rates, PRI, QRS, and ectopic beats
In recognizing PJC's, P waves...
may occur before or afterQRS
may occur only before or during QRS
can occur before, during, or after QRS
In recognizing PJC's, if visible, P waves...
is inverted in leads I, II, III and aVF
is inverted in leads II, III and aVF
is inverted in leads !, !! and aVF
is inverted in leads I, III and aVF
If P wave occurs before QRS in a PJC,
PRI will usually be equal to or less than 0.12 seconds
PRI will usually be less than 0.12 seconds
PRI will usually be 0.12 seconds
PRI will usually be greater than 0.12 seconds
there is no PRI
If no P wave occurs before QRS in a PJC,
then there is no PRI
PRI will usually be equal to or greater than 0.12 seconds
PRI will be less than 0.12 seconds
PRI will be 0.12 seconds
PRI will be greater than 0.12 seconds
QRS in a PJC,
is usually equal to or less than 0.12 seconds unless aberrantly conducted or an intraventricular conduction delay exists
is usually equal to or less than 0.21 seconds unless aberrantly conducted
is usually equal to or less than 0.12 seconds unless a P wave occurs before the QRS
is usually equal to or less than 0.21 seconds intraventricular conduction delay exists
is usually equal to or less than 0.12 seconds unless aberrantly conducted or accompanied by a PRI of greater than 0.12 seconds
is usually equal to or less than 0.12 seconds unless an intraventricular conduction delay exists, or accompanied by a PRI of greater than 0.12 seconds
When recognizing a PJC, all except the following are true:
rate is usually within normal range, rhythm is regular with premature beats, and p waves may occur before, during, or after QRS
QRS is usually greater than 0.12 seconds unless aberrantly conducted, rate is usually within normal ranges, and rhythm is regular with premature beats
PRI will usually be equal to, or less than 0.12 seconds if P wave occurs before QRS, rhythm will be regular with premature beats, and QRS is usually equal to or greater then 0.12 seconds
rate is usually within normal ranges but depends on underlying rhythm, QRS is usually equal to or greater than 0.12 seconds unless aberrantly conducted, and there will be no PRI if P wave occurs before QRS
Causes for PJC include all of the following except;
congestive heart failure, digitalis toxicity, stimulants, and mental and physical fatigue
acute coronary syndromes, mental and physical fatigue, valvular heart disease, and electrolyte imbalance
caffeine, only physical fatigue, valvular heart disease, and acute coronary syndromes
rheumatic heart disease, tobacco and other stimulants, acute coronary syndromes, and digitalis toxicity
Most individuals with PJCs are asymptomatic
PJCs...
may lead to symptoms of palpitations or feeling of skipped beats
always require treatment
are caused by stimulants, and thus should be avoided
are caused only by physical fatigue
A, C and D
Which of the following are true about junctional rhythms
rate: 40-60 rhythm: regular p waves: before and during QRS
rate: 30-50 rhythm: regular p waves: before, after and during QRS
rate: 40-60 rhythm: regular p waves: inverted if visible
rate: 40-60 rhythm: regular p waves: before, and after QRS
rate: 40-70 rhythm: regular p waves: before, after and during QRS; inverted if visible
when the rhythm is slower than expected, it is called
junctional bradycardia
deceletrated junctional rhythm
junctional tachycardia
what are the two types of rapid junctional rhythms
accelerated junctional rhythm and junctional tachycardia
junctional tachycardia and rapid junctional rhythm
rapid junctional rhythm and accelerated junctional rhythm
junctional tachycardia and junctional bradycardia
the two types of rapid junctional rhythms have bpms that range between
60-100 and 100-140
55-100 and 100-140
60-100 and 100-130
55-100 and 100-130
what is the difference between the two types of rapid junctional rhythms
rate
rhythm
p waves
all but the following are causes of accelerated junctional rhythm
acute myocardial infarction, CODP, rheumatic fever
hypokalemia, COPD, cardiac surgery and rheumatic fever
digitalis toxicity, acute myocardial infarction, caridac surgery and hypokalemia
acute myocardial infarction, digitalis toxicity and rheumatic fever
ventricles may assume responsibility for pacing the heart in all but which case;
SA node fails
SA node generates impulse but is blocked as it exists SA node
SA node discharge is faster than ventricles
irritable site in either ventricle produces early beat or rapid rhythm
ventricles may assume responsibility for pacing heart if the SA node discharge is slower than ventricles
when the SA node fails or its impulse is blocked as it exists the SA node, may assume responsibility
select all that apply. Ventricles may assume responsibility for pacing the heart if:
impulse from SA node generated but blocked as it exists SA node
SA node discharge slower than ventricles
we can recognize premature ventricular complexes by observing that the T wave is usually
in the opposite direction of QRS
parallel to QRS
in the same direction of QRS
non-existant
in premature ventricular complexes, all but which of the following are true
QRS typically greater than 0.12 seconds
occurs earlier than next expected sinus beat
T wave usually in opposite direction of QRS
arise from irritable focus in either ventricle
premature ventricular complexes arise from irritable focus in either ventricle
a PVC is usually followed by a
full compensatory pause
backward electrical impulse
a non-compensatory pause
2 sequential PVCs are called
runs or bursts
couplets
ventricular bigeminy
bigeminal PVCs
ventricular trigeminy
3 sequential PVCs are called
trigeminal PVCs
Bigeminal PVCs are when ____________ occurs
more than 3 sequential PVCs
2 sequential PVCs
every other beat is a PVC
every 3rd beat is a PVC
When every 3rd beat is a PVC, it is known as
ventrucular quadrigeminy
C and D
Quadrigeminal PVCs are when
there are 4 sequential PVCs
every other beat is a PVC, for greater than 4 occasions
every 4th beat is a PVC
uniform PVCs are distinct in that they
have similar morphology in same lead, and originate from the same ectopic focus
have similar morphology in same lead, and originate from different ectopic focus'
have different morphology, and originate from the same ectopic focus
have different morphology, and originate from different ectopic focus'
when PVCs have different morphology in the same lead they are easily recognized as...
uniform PVCs
multiform PVCs
R-on-T PVCs
ventricular rhythms
multiform PVC's
often (but not always) arise from different foci
always arise from different foci
never arise from different foci
PVCs are named R-on-T PVCs, because the
R wave falls on the T wave of preceding beat
T wave falls on the R wave of preceding beat
R wave refracts on the T wave of preceding beat
T wave refracts on the R wave of preceding beat
2 PVCs in a row are called
paired PVCs
bursts
salvo
"salvo," "run," or "burst" of VT are all ways of describing
greater than 5 PVCs in a row at a rate greater than 100 bpm
greater than 3 PVCs in a row at a rate greater than 50 bpm
greater than 5 PVCs in a row at a rate greater than 50 bpm
greater than 3 PVCs in a row at a rate greater than 100 bpm
greater than 3 PVCs in a row at a rate greater than 120 bpm
The rate of a PVC is
usually normal, but depends on underlying rhythm
usually higher than normal, but depends on underlying rhythm
usually lower than normal, but depends on underlying rhythm
usually normal, but depends on past medical conditions
The rhythm of a PVC
depends on underlying rhythm
depends on past medical history
depends on the conditions the patient are currently in
depends on underlying rhythm, with premature beats
P waves in a PVC
are usually absent
with retrograde condiction to atria, may appear after QRS
may appear after QRS, usually upright in ST-segment or T wave
may occur before after or during QRS
if visible, P wave is inverted
B and C
A, B, and C
In PVCs, QRS is
greater than 0.12 seconds, narrow and bizarre
usually in the same direction as the T wave
greater than 0.12 seconds, wide and bizarre
usually in the opposite direction of P wave
All of the following are causes of Premature Ventricular complex, except
normal variant, exercise, stimulants, increased sympathetic tone and hypoxia
stress and anxiety, medications, congestive heart failure, and valvular heart disease
digitalis toxicity, stress, myocardial ischemia, acid-base imbalance, and increased sympathetic tone
caffiene, TCA's, acute coronary syndromes, exercise and normal variant
Patients of PVC may be asymptomatic
patients of PVC who are symptomatic may complain of all the following except;
palpitations, racing heart, lower back discomfort
racing heart, neck discomfort, skipped beats
chest discomfort
if PVCs are frequent,
decreased cardiac output possible
increased cardiac output possible
no cardiac output possible
treatment of PVCs is dependent on all except which of the following
cause
signs and symptoms
clinical situation
mental and physical fatigue
These look just like a PVC, but appear LATE instead of early.
ventricular escape beats
'safety' mechanisms
AV junctions
compensatory pauses
three or more ventricular escape beats in row, with a rate of 20-40 bpm is indicative of
idiocentricular rhythm
agonal rhythm
premature junctional complexes
agonal rhythm shows a ventricular rate of
less than 20 bmp
greater than 20 bmp
equal to 30 bpm
greater than 30 bpm
between 20 and 30 bpm
you are given the following information... rate:20-bpm rhythm: essentially regular P waves: usually absent PRI: none What do you diagnose?
idioventricular rhythm
premature junctional complex
premature ventricular complex
accelerated idioventricular rhythm
P waves in idioventricular rhythms are usually absent, or with retrograde conduction to atria, may appear after before( after, before ) QRS (usually upright in ST-segment or T wave)
if no P wave occurs before QRS in _____________, then there is no PRI. In ____________, there is always no PRI.
PJCs, idioventricular rhythms
idioventricular rhythms, PJCs
rapid junctional rhythms, accelerated idioventricular rhythms
accelerated idioventricular rhythms, rapid junctional rhythms
in this rhythm, the T wave is frequently in the opposite direction of QRS complex
acceletated junctional rhythm
premature ventricular complexes
introventricular rhythms may occur in all of the following cases, except for
SA node and AV junction quit
rate of discharge of SA node or AV junction intrinsic rate is slower than ventricular rate
digitalis toxicity
impulses generated by the supracentricular pacemaker site are firing too quickly
metabolic imbalances
slow rate and loss of atrial kick in idioventricular rhythms may result in upwards cardiac output
Scenario: your patient has a QRS greater than 0.12 seconds, but an essentially regular rhythm. You notice three or more ventricular escape beats in a row, with a rate of 20-40 bpm. What should you do?
lidocaine
TCP or atropine
increase MVO2
predispose patient to ventricular dysrythmmias
three or more ventricular escape beats occur in a row, rate of 41-100 bpm. What do you diagnose?
ventricular tachycardia
some physicians consider ventricular rate range of AVIR to be 41-100, while others consider it to be 41-120 bpm
P waves are usually absent in this rhythm, though with retrograde conduction to atria, may appear after QRS (usually upright in ST-segment or T wave)
torsades de pointes
A and D
acelerated idioventricular rhythm appears in all of the following, with the exception of;
often seen during the first 12 hours of MI
post-reperfusion therapy (successful)
accelerated sinus rate
decelerated sinus rate
acute mypocarditis
accelerated idioventricular rhythm appears in all of the following, with the exception of;
cocaine toxicity
subarachnoid hemorrhage
acute myocarditis
hypertensive heart disease
all of the above are causes of accelerated idioventricular rhythm
If a patient with accelerated idioventricular rhythms is symptomatic because of loss of atrial kick, treatment can include all of the following with the exception of;
atropine
atrial pacing
ventricular antiarrhythmics
treatment is usually unnecessary in patients with accelerated idioventricular rhythms
your patient is displaying three or more PVCs in a row, rate of greater than 100 bpm. What are you observing?
accelerated idioventricular
idioventricular
asystole
nonsustained ventricular tachycardia lasts ____________, while sustained VT ________________
less than 30 seconds, more than 30 seconds
more than 30 seconds, less than 30 seconds
less than 60 seconds, more than 60 seconds
more than 60 seconds, less than 60 seconds
all of the following are possible causes of ventricular tachycardia, with the exception of;
acute coronary syndromes, cardiomyopathy and TCA overdose
TCA overdose, cocaine abuse, trauma
acid-base imbalance, mitral valve prolapse, digitalis toxicity
brugada, electrolyte imbalance, invasive cardiac procedures
myocardial contusion, abnormal QT interval, stimulants such as caffeine and tobacco
this phenomenon is a chaotic rhythm originating in the ventricles. It is always pulseless
ventricular fibrillation
ventricular fibrillation is not caused by
environment
electrolyte imbalance
hypertrophy
electrolyte imbalances
decreased SNS activity
the absence of any (ventricular) rhythm
all of the following are causes of first degree AV blocks, with the exception of which of the following;
AV node ischemia/injury
acute MI
some meds
decreased vagal tone
This type of block is defined as a prolongation of the PR interval on an ECG to more than 0.20 seconds
1st degree AV block
type 1, 2nd degree AV block
type 2, 2nd degree AV block
3rd degree AV block
your patient reveals a history of congestive heart failure on digoxin. He does not have any complaints of nausea, palpaitations, or chest pain. You run an ECG, and notice that the rhythm is regularly irregular, and the ratio of Ps to QRSs is 1:1 underlying rhythm and 2:1 where dropped beat occurs. How do you diagnose?
2nd degree AV block, type 1
2nd degree AV block, type 2
ischemic heart disease
2nd degree av block type 1 is more serious than 2nd degree av block type 2
which of the following is not a cause for type 1, 2nd degree AV blocks
increased parasympathetic tone
anterior wall MI
aortic valve disease
mitral valve prolapse
left coronary artery disease, anterior wall MI, and fibrosis of conduction system are all causes of which type of AV block
2nd degree, type 1
2nd degree, type 2
1st degree
3rd degree
your patients ECG reflects a slow rate, with present and upright P waves. You notice that the rhythm is regular for P waves, but irregular for QRS. For instance, the last impulse appeared on the ECG as P wave with no QRS after. These are features of a
