STONECREST HEALTH · INTERACTIVE LEARNING
Free ECG Simulator & Rhythm Strip Practice
Explore cardiac rhythms on a live monitor and a stationary ECG paper strip. Choose a rhythm, adjust its heart rate, and compare the waveform in monitor, paper, or split view.
Synthetic educational use only. These mathematically generated waveforms are not patient data and are not for clinical diagnosis, monitoring, or treatment.
Use the rhythm controls to explore the library. Paper strips stay fixed; use Capture monitor strip to take a new snapshot. For more room, open the full ECG Lab above.
Enrolled students complete course-linked examinations and receive recorded grades inside LearnWorlds.
BUILD YOUR RHYTHM RECOGNITION SKILLS
How to practice ECG interpretation
Start with a systematic review: check the rate and regularity, identify P waves, compare their relationship to QRS complexes, and measure the intervals. Hide rhythm labels to test yourself, then reveal the answer and compare several rhythms.
Calculate heart rate
At 25 mm/s, one small horizontal square represents 0.04 seconds and one large square represents 0.20 seconds. For a regular rhythm, divide 300 by the number of large squares between successive R waves. For an irregular rhythm, count QRS complexes in a 6-second strip and multiply by 10 for an estimate.
Measure the PR interval
Measure from the beginning of the P wave to the beginning of the QRS complex. The usual adult range is 0.12–0.20 seconds, or 3–5 small squares at 25 mm/s. Compare consecutive beats and look for changes or dropped complexes.
Review QRS duration
Measure from the first QRS deflection to the end of the complex. A narrow adult QRS is generally less than 0.12 seconds. Compare the shape and width across beats; a single measurement does not establish a diagnosis.
Use calibrated ECG paper
The lab uses 25 mm/s and 10 mm/mV, with five small cells per large square. The paper strip stays stationary. Use the calipers to measure intervals and Capture monitor strip to take a new snapshot.
Explore the rhythm library
Practice 28 rhythm scenarios: normal sinus rhythm, sinus bradycardia and tachycardia; atrial fibrillation, atrial flutter and SVT; junctional and idioventricular rhythms; PVCs, ventricular tachycardia, polymorphic VT and torsades; first-degree, Mobitz I, Mobitz II and complete AV block; ventricular fibrillation and asystole; and atrial, ventricular and dual-chamber pacing with capture and pacing failure examples.
PEA is also presented as a teaching scenario. An organized ECG alone cannot establish PEA—absence of a pulse requires clinical assessment. All lab waveforms are synthetic educational examples.
Learning references: ECG waves and intervals · ECG interpretation fundamentals.
TAKE YOUR NEXT LEARNING STEP
Enjoy practicing ECG rhythms? Learn to interpret them professionally.
Explore Stonecrest’s EKG/ECG Telemetry Monitor Technician program. Build your knowledge of cardiac conduction, rhythm interpretation, lead placement, artifact recognition, and documentation through structured online lessons, practice, and instructor support.
Applications are free. An application is not enrollment; enrollment remains pending approval and no tuition is collected now.