Educational reference · Not a medical device
Rhythm strips,
explained the way nurses learn them.
Identifying traits, intervals, and verification steps for the rhythms tele and ED nurses see most. These pages exist as study material and bedside refresher. They do not diagnose, and they don’t replace your facility’s approved interpretation.
The 5-step method
Every strip, read the same way.
Most nursing schools teach a version of this. Different orders, same intent. Use it as the spine; each reference page below adds the specifics for that rhythm.
- 1
Rate
Count R-R intervals — 300 / (number of large boxes) for regular rhythms; six-second method (count complexes × 10) for irregular.
- 2
Rhythm
Regular or irregular? Walk a caliper across at least six R-R intervals. Regularly irregular vs. irregularly irregular changes the differential.
- 3
P waves
Present? Upright in lead II? Before every QRS? Same morphology? P-wave changes carry most of the rhythm story.
- 4
PR + QRS
PR 0.12–0.20s, QRS < 0.12s. Long PR → AV block. Wide QRS → ventricular origin or aberrancy.
- 5
QT / QTc
Use QTc (Bazett or Fridericia) because raw QT depends on rate. Critical at > 500ms — flag pharmacy.
Reference library
5 rhythms, each with the full breakdown.
Rhythm
Normal Sinus Rhythm — Nurse Reference
Educational reference: how to identify normal sinus rhythm on a strip. Not a medical device.
Open reference →Rhythm
Atrial Fibrillation — Nurse Reference
Educational reference: how to identify atrial fibrillation on a rhythm strip. Verify clinically.
Open reference →Rhythm
Sinus Tachycardia — Nurse Reference
Educational reference: how to identify sinus tachycardia on a rhythm strip. Verify clinically.
Open reference →Rhythm
Sinus Bradycardia — Nurse Reference
Educational reference: how to identify sinus bradycardia on a rhythm strip. Verify clinically.
Open reference →Rhythm
Heart Blocks — Nurse Reference
Educational reference: 1st, 2nd, and 3rd degree AV blocks on a rhythm strip. Verify clinically.
Open reference →
Frequently asked
About this reference library.
Is this a medical device or a diagnostic tool?
No. RN PocketPal is positioned as educational decision-support. The rhythm strip reference pages are study material and bedside refreshers. The Rhythm Reader feature (a separate tool) returns probabilities with full intervals so you can verify with calipers. Diagnosis is the clinician's responsibility.
How do I verify what I see on a strip?
Calipers across at least six R-R intervals for regularity. Lead II for P-wave morphology. Patient's clinical context — sinus tachycardia and bradycardia look like NSR with rate variation, but the differential isn't the same. When in doubt, refuse to interpret and escalate.
Why does the Rhythm Reader refuse to guess sometimes?
Because confidently wrong is worse than honestly uncertain. Below ~70% top-1 confidence the model returns "rhythm uncertain — verify with calipers" instead of guessing. We calibrate the confidence so 92% actually means 92% — not the uncalibrated softmax most ML demos ship.
Are these reference pages a substitute for ACLS training?
No. These pages help you keep recognition skills warm between trainings. ACLS, BLS, and PALS courses cover the protocols + scenarios you actually need to run a code — this reference is the in-between layer that helps you spot the rhythm faster when you're paged at 0300.
Try the Rhythm Reader
Reading the strip + taking the photo = one tool.
RN PocketPal is live on Google Play. The Rhythm Reader is a Pocketpal Pro feature; the reference library you’re browsing is free for everyone.