Junctional Rhythms

Drag and Drop

The P Wave represents ​

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. The QRS complex represents ​

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. The T wave represents ​

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Drag these tiles and drop them in the correct blank above

atrial depolarization

ventricle depolarization

ventricle repolarizations

Multiple Choice

A normal PR Interval is

• 0.12-0.20

• 0.36-0.44

• 0.04-0.08

• 0.04-0.12

Multiple Choice

With sinus tachycardia, the impulse arises from the

• SA node

• AV node

• bundle branches

• Purkinje fibers

Drag and Drop

With Sinus Bradycardia, the P waves are ​

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, the P-P interval is ​

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, the PR interval is ​

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, the QRS complex is ​

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and the rate is ​

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upright

regular

0.12-0.20

<0.12

<60 bpm

inverted

irregular

0.04-0.08

>100 bpm

60-100 bpm

Multiple Choice

With Sinus Bradycardia, the impulse originates in the

• SA node

• AV node

• bundle branches

• Purkinje fibers

Drag and Drop

With sinus tachycardia, P waves are ​

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, P-P interval is ​

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, PR interval is ​

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, QRS complex is ​

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, and the rate is ​

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.

Drag these tiles and drop them in the correct blank above

upright

regular

0.12-0.20

<0.12

100-160 bpm

<60 bpm

inverted

irregular

0.04

Multiple Choice

True or False

Atrial flutter has what is known as a saw tooth pattern.

• True

• Falsec

• I have no idea

• Could be either

Dropdown

In Atrial Flutter, the impulse originates outside the ​

Select answer

Things to Remember

●Junctional arrhythmias occur at the AV
node/bundle of His

○The SA node is suppressed and fails
to conduct

●This causes the electrical activity to the
atria flow backwards causing in an
inverted P wave (retrograde
depolarization)

**Sometimes atrial arrhythmias are mistaken for
junctional**

How to know the difference:
Look at the P-R interval

●Inverted P waves & normal P-R interval=
atrial

●Inverted P waves & <0.12 P-R interval=
junctional

PREMATURE JUNCTIONAL

COMPLEXES (PJC)

Early impulse that occurs before the next expected beat

P Wave could occur before, after or can be buried within the QRS complex

Causes: toxic levels of digoxin, caffeine, inferior wall MI, heart failure

JUNCTIONAL ESCAPE

●Impulse originating from the AV node (acting as a backup pacemaker

●Atria and ventricles receive the impulse simultaneously

●Absent or inverted P waves

●HR will not exceed 40-60 bpm (coming from the AV node)

○Can exhibit signs of reduced cardiac output due to lower HR and lack of
atrial kick

●Causes: sick sinus syndrome (group of heart issues that affect the SA node), electrolyte imbalance, digoxin toxicity, inferior wall MI

●Same as Junctional Escape, but the rate is 60-100
(absent or inverted P waves)

●Does not usually have signs of decreased cardiac output

●Causes: digoxin toxicity, hypokalemia, hyperkalemia,
inferior/posterior MI

JUNCTIONAL TACHYCARDIA

●Same as escape and accelerated but the HR is between 100-150
bpm (a form of SVT--discussed on next slide)

●Because of tachycardia, the patient is likely to experience
palpitations or fluttering

SUPRAVENTRICULAR TACHYCARDIA (SVT)

●No necessarily a junctional arrhythmia

●Included here because the impulse comes from above the
ventricles

●HR is >150 bpm

●P waves are not visible, P-R interval is unmeasurable

Match

Match the following

• Junctional Escape

• Accelerated Junctional

• Premature Junctional Complex (PJC)

• Junctional tachycardia

• Supraventricular tachycardia

inverted/absent P waves; HR 40-60

Inverted/absent P waves; HR 60-100

early impulse

HR 100-180 (ventricular rate);

HR 150-250); no P/T waves

• inverted/absent P waves; HR 40-60

• Inverted/absent P waves; HR 60-100

• early impulse

• HR 100-180 (ventricular rate);

• HR 150-250); no P/T waves

Open Ended

After today, how do you feel about the arrhythmias we have discussed? What areas do you need more review on?