Junctional Rhythms Flashcards
What is retrograde conduction?
When the impulse spreads upwards from AV node to the atria
In junctional arrhythmias does the p wave precede the QRS complex consistently?
NO
Depends on whether the Atria or ventricles were depolarized first
What comes first if the ventricles are depolarized before the atria?
The QRS complex
What comes first if the atria is depolarized before the ventricles?
The P wave
What happens when the atria and ventricles depolarize simultaneously?
The P waves will be hidden within the QRS complex
How long is the PRI In junction all rhythms?
Less than .12 second
An inverted P wave originates in what two places?
AV node
Atria
What are four basic mechanisms that produce Arrhythmias in the AV junction?
Premature junctional complex
Junctional escape rhythm
Accelerated junctional rhythm
Junctional tachycardia
Premature junctional complex
Regularity
Depends on underlying rhythm
Premature junctional complex
Rate
Depends on underlying rhythm
Premature junctional complex
P Wave morphology (2)
Inverted
Falls before during or after QRS complex
Premature junctional complex
PRI
Less than .12
Only measured if precedes QRS complex
Premature junctional complex
QRS
Less than .12
Junctional escape rhythm
Regularity
Regular
Junctional escape rhythm
Rate
40-60
Junctional escape rhythm
P wave morphology
Inverted
Can fall before after or during QRS complex
Junctional escape rhythm
PRI
Less than .12 if p wave precedes QRS complex
Junctional escape rhythm
QRS
Less than .12
What two categories are junctional tachycardia divided into?
Accelerated junctional rhythm
Junctional tachycardia
What rate is the junction firing during accelerated junctional rhythm?
60-100
What rate is the junction firing during junctional tachycardia?
100-180
Accelerated junctional tachycardia
Regularity
Regular
Accelerated junctional tachycardia
Rate
60-100
Accelerated junctional tachycardia
P wave
Inverted before after or in between QRS complex
Accelerated junctional tachycardia
PRI
Less than .12 only if precedes QRS complex
Accelerated junctional tachycardia
QRS complex
Less than .12
Junctional tachycardia
Regularity
Regular
Junctional tachycardia
Rate
100-180
Junctional tachycardia
P Wave
Inverted
Can fall before after or in between QRS complex
Junctional tachycardia
PRI
Less than .12 if preceding QRS complex
Junctional tachycardia
QRS
Less than .12
What is the only difference you will see on an EKG between:
junctional escape rhythm
accelerated junctional rhythm
junctional tachycardia?
The rate
What is the rate for junctional escape rhythms?
40-60
What three junctional arrhythmias are caused by irritability?
Premature junctional complex
Junctional tachycardia
Accelerated junctional tachycardia
What is supraventricular tachycardia? (SVT)
Used to describe a category of several regular tachyarrythmias that can’t be identified more accurately
When do you label an EKG as a supraventricular tachycardia?
Regular arrhythmia
Indistinguishable p wave
Similar rate ranges
What rate ranges do you commonly call supraventricular tachycardia?
150-250 BPM
Where do impulses go when the AV node assumes pacemaking responsibility?
In the atria and ventricles
