Read any rhythm
with confidence.
CardioLab is a live ECG simulator where students, nurses, paramedics and physicians watch rhythms trace in real time, from normal sinus to STEMI, and learn what every wave really means.
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Everything in one place
A real monitor, in your browser.
Built to mirror what you see at the bedside: calibrated ECG paper, animated waveforms, and the measurements that drive every clinical decision.
A living rhythm library
From normal sinus to atrial fibrillation, AV blocks and full STEMI evolution. Every rhythm animates exactly as it would on a real cardiac monitor.
Single-lead & 12-lead
Flip between a focused Lead II strip and a complete 12-lead layout to train pattern recognition the way you'll actually see it on the floor.
Real measurements, live
Watch HR, RR, PR, QRS, QT and QTc update beat by beat. Adjust the heart rate and noise level to see exactly how the intervals respond.
Three steps
From textbook to monitor in seconds.
Pick a rhythm
Browse a categorized library (sinus node, atrial, AV blocks, junctional, ventricular and STEMI) and select what you want to study.
Watch it trace live
The waveform animates in real time across calibrated ECG paper at 25 mm/s and 10 mm/mV, just like the real thing.
Compare & measure
Switch to the 12-lead view, read the intervals, and connect each trace to its diagnosis until recognition becomes instinct.
For every cadre
Made for everyone who reads a monitor.
Whether you're learning your first rhythm or sharpening a skill you use every shift, CardioLab meets you where you are.
Students
Build rock-solid fundamentals before clinicals. Watch the textbook come to life, one rhythm at a time.
Doctors & residents
Sharpen rapid recognition of arrhythmias and STEMI patterns on demand, anytime you have two minutes.
Nurses & paramedics
Train monitor reading and confident rhythm calls for the bedside and the field, without the pressure.
Educators & institutions
A ready-made teaching tool for classrooms, simulation suites and skills labs, with no setup required.
Built on real vectors
Physiologically faithful, not just animated.
CardioLab is a free educational ECG/EKG simulator. Limb leads are derived from a single frontal-plane vector (Einthoven and Goldberger exact), and ST injury currents are modelled as projected vectors, so STEMI elevation, reciprocal depression, and the posterior mirror pattern stay physiologically consistent across all 12 leads.