EMS Registry ReadyExample 1 · lead II · 6 seconds
- Rate
- 225/min22 QRS complexes in 6 seconds × 10 = 220/min
- Rhythm
- Regular
- P waves
- Not visible
- P to QRS
- No visible P waves (retrograde P buried in the QRS)
- PR
- None to measure
- QRS
- 0.11 s, narrow
Supraventricular tachycardia (AVNRT) on an ECG strip
Regular, narrow and 150-250/min, with no visible P waves.
What to look for
A regular narrow-complex tachycardia at 150-250/min, and you won't find P waves. The retrograde P is buried in the QRS.
Examples
Each strip is 6 seconds of lead II, drawn to scale (25 mm a second, 10 mm a millivolt), so you can count boxes the way you would on paper. Each one is a different example, measured below it.
Example 2 · lead II · 6 seconds
- Rate
- 157/min15 QRS complexes in 6 seconds × 10 = 150/min
- Rhythm
- Regular
- P waves
- Not visible
- P to QRS
- No visible P waves (retrograde P buried in the QRS)
- PR
- None to measure
- QRS
- 0.07 s, narrow
Example 3 · lead II · 6 seconds
- Rate
- 245/min24 QRS complexes in 6 seconds × 10 = 240/min
- Rhythm
- Regular
- P waves
- Not visible
- P to QRS
- No visible P waves (retrograde P buried in the QRS)
- PR
- None to measure
- QRS
- 0.08 s, narrow
Don't confuse it with
- Sinus tachycardia
Sinus rhythm over 100/min: regular, with an upright P before every QRS.
- Atrial flutter
Sawtooth waves at about 300/min, with a QRS after every 2nd, 3rd or 4th wave.
Want a new strip every time? The ECG Drill in the app draws a fresh, measured example on every try and steers you toward the rhythms you miss. It's part of the Paramedic level, and you can try 5 strips a day free.
Try the ECG Drill