Fifty-six modules, in order, one idea each. It starts with the people who found the conduction system, builds one normal beat interval by interval, and works out from there — block, ectopy, fibrillation and flutter, pre-excitation, re-entry, the ventricular tachycardias and the channelopathies — with the circuit running live beside every idea. No rhythm is scripted: every one of them emerges from refractoriness and recovery, and you can break any of them with a slider.
Modules marked EP level go into catheter-laboratory detail — the Jackman pathways, Nogami’s P1 and P2, entrainment of scar VT — and can be left for a second pass.