Ch. 5 Notes: Rhythm Strip Interpretation and Sinus Rhythms Flashcards
What is used to determine the cardiac rhythm?
Waveform, segments, and intervals
What are the 5 steps to identifying components of the rhythm?
- Atrial rhythm and rate
- Ventricular rhythm and rate
- P wave morphology
- PR interval
- QRS duration and morphology
What lead is generally used for rhythm evaluation?
Lead II
What are the two options for rhythms?
Irregular or regular
How do you determine if the rhythm is regular or irregular?
Regular rhythms have equal spacings and irregular rhythms don’t
How do you measure the atrial rhythm?
From the beginning of the P wave to the beginning of the next P wave (P-P interval)
How do you measure the ventricular rhythm?
From the R wave to the next R wave (R-R interval)
How do you calculate atrial and ventricular rates?
Count the number of small boxes between the P-P or R-R intervals and divide 1500 by that number (or look on chart)
What method should you use to calculate the atrial and ventricular rates for irregular rhythms?
Use the 6-second method; count the number of P or R waves in a 6 second strip and multiply by 10
What is normal P wave morphology?
Upright and rounded
What should normally follow every P wave?
QRS complex
How do you measure the PR interval?
From the start of the P wave to the start of the QRS complex
How do you measure the QRS duration?
From the beginning of the Q wave to the end of the S wave (J point)
What are signs of decreased cardiac output?
Confusion, dizziness, syncope, chest pain, low BP, decreased pulse volume, nausea, cramping, pallor, cool skin, diaphoresis, mottled skin, tachypnea, shortness of breath
Which rhythm is used to compare to other rhythms?
Normal sinus rhythm
Where does the normal sinus rhythm originate from?
The SA node
What is the criteria for normal sinus rhythm?
- Atrial rhythm/rate: regular, 60-100 bpm
- Ventricular rhythm/rate: regular 60-100 bpm
- P wave morphology: uniform, upright, rounded, before every QRS complex
- PR interval: 120-200 ms or 0.12-0.20 s
- QRS duration and morphology: 60-120 ms or 0.06-0.12 s, consistent and without variations
What is the criteria for sinus bradycardia?
The same as normal sinus except for the atrial and ventricular rates which are less than 60 bpm
What treatment may be needed for sinus bradycardia?
Medication or a pacemaker