EMS Registry ReadyExample 1 · lead II · 6 seconds
- Rate
- 133/min13 QRS complexes in 6 seconds × 10 = 130/min
- Rhythm
- Regular
- P waves
- Upright in II, uniform
- P to QRS
- 1:1, a P before every QRS
- PR
- 0.17 s
- QRS
- 0.09 s, narrow
Sinus tachycardia on an ECG strip
Sinus rhythm over 100/min: regular, with an upright P before every QRS.
What to look for
Sinus rhythm over 100/min, with an upright P before every QRS. As the rate climbs, each P creeps closer to the T wave before it. Once the P merges into the T, you can't tell the rhythm from SVT on a strip. The strips here stop at 150/min, the usual line where SVT is considered, and they always keep the P clear of the T.
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
- 116/min12 QRS complexes in 6 seconds × 10 = 120/min
- Rhythm
- Regular
- P waves
- Upright in II, uniform
- P to QRS
- 1:1, a P before every QRS
- PR
- 0.12 s
- QRS
- 0.10 s, narrow
Example 3 · lead II · 6 seconds
- Rate
- 106/min11 QRS complexes in 6 seconds × 10 = 110/min
- Rhythm
- Regular
- P waves
- Upright in II, uniform
- P to QRS
- 1:1, a P before every QRS
- PR
- 0.18 s
- QRS
- 0.10 s, narrow
Don't confuse it with
- Supraventricular tachycardia (AVNRT)
Regular, narrow and 150-250/min, with no visible P waves.
- 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