EKG Interpretation Flashcards
Normal firing rate of SA node
60-100
Normal firing rate of AV node
40-60
Normal firing rate of purkinge fibers?
20-40
What does the P wave represent?
Atrial depolarization
What does the QRS complex represent?
Ventricular depolarization
What does the T wave represent?
Ventricular repolarization or recovery of the ventricles
How long should the P-R interval last on an EKG?
less than 0.2 sec or 5 small boxes
How long should the QRS complex last on an EKG?
less than 0.12 sec or 3 small boxes
What is the difference between the relative and absolute refractory periods?
Absolute- if the node fires, nothing happens
Relative- if the node fires, you can have a premature beat
*Like flushing the toilet
What 5 questions determine an EKG strip?
- What is the bpm?
- Are the P waves similar, regular, & upright?
- Is the QRS tight? (less than 3 small boxes)
- QRS for every P wave?
- IS the P-R interval less than 0.2 sec (5 small boxes or 1 large box)
What is this?
Atrial Fibrilation
- 90 bpm- NSR
- P wave- no
- QRS- less than 3 boxes
- QRS for every P- no
- PR interval- varies
What is this?
Atrial Flutter
- 70 bpm
- P-waves: regular, same and upright
- QRS- less than 3 boxes
- P-R interval- less than 5 boxes
- QRS for every P- NO, more P’s than QRS’s
What is this?
First degree Heart Block
- 60 bpm
- P waves- regular, upright, same
- QRS- less than 3 boxes
- QRS for every P- yes
- P-R interval- >5seconds, thus prolonged b/c delayed AV conduction
What is this?
Normal Sinus Rhythm
- 80 bpm- NSR
- P waves- regular, same and upright
- QRS- less than 3 boxes
- A P-wave for every QRS- yes
- P-R interval- less than 5 boxes
What is this?
Sinus Bradycardia
- 50 bpm- bradycardic
- P wave- regular, same, upright
- QRS- less than 3 boxes
- QRS for every P- yes
- P-R interval- less than 5 boxes
What is this?
Sinus Tachycardia
- 140 bpm- tachycardia
- P wave- regular, same and upright
- QRS- less than 3 boxes
- P-R interval- less than 5 boxes
- QRS for every P- yes
What is this?
Third degree heart block
- 50 bpm- bradycardia
- P wave- altered
- QRS- wide more than 3 boxes
- QRS for every P- no
- P-R interval- absent
What is this?
Second degree heart block, Type 1
- 60 bpm- NSR
- P wave- regular, same and upright
- QRS- less than 3 boxes
- QRS for every P- no
- P-R interval- progressively legnthens to absent QRS
What is this?
Second degree heart block- Type 2
- 50 bpm
- P waves- regular, same and upright
- QRS- less than 3 boxes
- QRS for every P- No
- P-R interval- irrgular intervals with absent QRS’s here and there
