Gallery · reference compositions (R2, R2F render + primitives lane)
The spark, and how the ECG sees it
Five figures for Chapter 6 and the start of Part III, all on ONE recorded simulated heartbeat — the coupled sinus beat: the SA node fires, the wave crosses the atria, the AV node holds it, the His–Purkinje network delivers it, the ventricles activate and recover, and a torso model turns all of that into the ECG on the skin. Simulated and for teaching only; not a diagnostic tool.