Junctional Rhythms

Question 1

Steps for Interpreting EKG

Answer 1

> Is it regular or irregular?
-look at the P-P (atrial) if present and R-R (ventricular)

> What is the rate?

> Are there P waves?

• do they look the same or are they different?
• is there a P wave in front of every QRS?

> If there are P waves, is there a regular PR interval?
-is it 0.12-0.20 seconds?

> What does the QRS look like?

• narrow (< 0.10)- above ventricles
• wide (> 0.10)- above the ventricles- wide QRS
• wide (> 0.10)- below the ventricles

> What is the QT interval?

• is it between 0.36-0.44 seconds?
• normal QT should be less than half the R-R interval (less than R-R interval is normal, the same it is borderline, and longer it is prolonged)

> Interpretation?
Intervention?

Question 2

The different junctional rhythms

Answer 2

• Premature junctional complexes (PJCs)
• Junctional Rhythm (40-60 bpm)
• Accelerated Junctional Rhythm (60-100 bpm)
• Junctional Tachycardia (100-180 bom)

> the only difference is the rates
in PJC rate is determined by the underlying rhythm

Question 3

P wave of the AV junction

Answer 3

• may appear before, during, or after the QRS
• no “p” wave before the QRS or
• inverted “p” wave before the QRS, or
• an inverted “p” wave after the QRS

Question 4

Premature Junctional Complexes (PJC)

Answer 4

arises from an irritable site within the AV junction that fires before the next expected sinus beat

• Narrow QRS
• PR interval: <0.12

Question 5

Difference between PACs and PJCs

Answer 5

• the PR interval of a PAC is normal 0.12-0.20

- the PR interval of a PJC is <0.12

Question 6

ECG characteristics of a PJC

Answer 6

• Regular: except for premature beats
• Rate: depends on underlying rhythm
• P wave: either inverted and before QRS, during QRS w/ no “p” wave, or inverted after the QRS
• PR interval: if “p” wave before QRS it is 0.12 or less; if “p” wave in the QRS or after the QRS there is no PR interval
• QRS complex: 0.10 seconds (wide)
• QT interval: 0.44 or less

Question 7

How to treat a PJC

Answer 7

• assess patient

- correct the underlying cause

Question 8

Junctional Rhythm on EKG

Answer 8

• Regular: Yes
• Rate: 40-60 bpm
• P waves: either inverted and before the QRS, during QRS w/ no “p” wave, or inverted after the QRS
• PR interval: if “p” wave before the QRS it will be 0.12 or less; if “p” wave in the QRS or after the QRS there is no PR interval
• QRS complex: 0.10 seconds (wide)
• QT interval: 0.36-0.44 (the lower the rate the longer the QT)

Question 9

Accelerated Junctional Rhythm

Answer 9

• Regular: Yes
• Rate: 60-100 bpm
• P waves: either inverted and before the QRS, during the QRS w/ no “p”, or inverted and after the QRS
• PR interval: if “p” wave before the QRS it is 0.12 or less; If “p” wave in or after the QRS there is no PR interval
• QRS complex: 0.10 seconds (wide)
• QT interval: 0.36-0.44 seconds (the lower the rate the longer the QT)

Question 10

Junctional Tachycardia

Answer 10

• Regular: Yes
• Rate: 100-180 bpm
• P waves: either inverted and before QRS, during QRS w/ no “p” wave, or inverted and after the QRS
• PR interval: If “p” wave before QRS it is 0.12 or less, if the “p” wave is in the QRS or after the QRS there is no PR interval
• QRS complex: 0.10 seconds (wide)
• QT interval: 0.44 or less (
• often starts abruptly and is preceded by a PJC

Question 11

What to do about Junctional Rhythms

Answer 11

• assess patient
• treat if low or high heart rate (HR) is causing symptoms
• identify and treat underlying cause