LATEST EXAM WITH VERIFIED
QUESTIONS AND RELIABLE ANSWERS
PLUS DETAILED RATIONALES (MOST
RECENT !!!)
1. Normal Sinus Rhythm (NSR)
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Lead II - 6-second strip
R R R R R R R R
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P QRS T P QRS T P QRS T P QRS T P QRS T
Rate: 60-100 bpm (Regular)
P waves: Upright & uniform before each QRS
PR Interval: 0.12-0.20 sec (1-2 small boxes)
QRS: <0.12 sec (narrow)
2. Sinus Bradycardia
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Rate: <60 bpm (approx 45-50 bpm)
R R R R R R
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P QRS T P QRS T P QRS T P QRS T P QRS T
Everything else is the SAME as NSR - just SLOWER
P waves are upright and normal
PR interval is normal (0.12-0.20)
QRS is narrow
3. Sinus Tachycardia
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Rate: 100-150 bpm (approx 120 bpm)
R R R R R R R R R R R
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P QRS P QRS P QRS P QRS P QRS P QRS
Everything is the SAME as NSR - just FASTER
P waves are visible and upright
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,PR interval is normal
QRS is narrow
Rate >100 bpm but <150 bpm
4. Sinus Arrhythmia
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Rate varies with respiration (60-90 bpm)
R R R R R R R R R
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P QRS P QRS P QRS P QRS P QRS P QRS P
Characteristic: R-R intervals are IRREGULAR
P waves are ALL present and NORMAL
The rhythm speeds up during INSPIRATION
The rhythm slows down during EXPIRATION
THINK: "Irregularly irregular but with P waves"
5. Atrial Fibrillation (A-Fib)
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Rate: Usually 100-150 bpm (or variable)
R R R R R R R R
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P? QRS P? QRS QRS P? QRS QRS P? QRS
Characteristic:
- NO discernible P waves
- wavy baseline (fibrillatory waves) - looks like "sawtooth" or "squiggly line"
- R-R intervals are COMPLETELY IRREGULAR
- QRS is narrow (unless aberrancy)
- "Irregularly irregular"
- Ventricular rate is often fast but can be controlled
6. Atrial Flutter
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Rate: Atrial rate 250-350 bpm, Ventricular rate variable
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R R
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F F F F F F F F F F
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