CardiacCycle logoCardiacCycle 3D制作人：于快 (yukuai@gmc.edu.cn)
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THE HEART IN MOTION

Drag to orbit · scroll to zoom · click to explore

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R↑ AL
Preparing your physiology laboratory…

With the 3D view focused: W/A/S/D orbit, +/− zoom. Use the structure menu to inspect anatomy.

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Follow the pressure gradient

Select a chamber, vessel, or valve to connect its anatomy with the current phase.

PRESSURE–VOLUME LOOP

LV

FIVE CELLS. ONE CONDUCTION SEQUENCE.

Cell-specific action potentials with activation offsets. Voltage: mV; time: ms.

Epicardial cells usually repolarize earlier because their action potentials are shorter. Reversal of the repolarization sequence and polarity helps explain an upright T wave in leads with a positive QRS; the full T wave reflects three-dimensional regional gradients. The long ventricular refractory period prevents summation and tetanus.

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v1.0.0

Heart mesh: Z-Anatomy / BodyParts3D (CC BY-SA), modified · Source & changes

Current values · paused

A frozen reading from the shared clock. Close this dialog and use Play or the timeline to continue.

Current values · paused

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Welcome to the Cardiac Cycle Lab

The heart starts beating once it has loaded, and the heart, curves and readouts share one clock. Start with normal sinus rhythm: pause at valve closure and compare the pressure gradient, volume and heart sound. Scroll down for the action potentials of five cardiac cells; tick "Why is the T wave upright?" to compare endocardial and epicardial repolarization. On the realistic heart, X-ray shows the valves and chords; the 2D heart gives a simpler drawing. Choose the exercise scenario to see diastasis disappear at high heart rates. Press "⚡ Ectopic stimulus" on the Wiggers card: inside the effective refractory period the ventricles do not respond; after it a premature ventricular beat follows, then a full compensatory pause. On the Rhythm strip the two RR intervals around it add up to two sinus RR intervals, with a weak pulse and a stronger beat after the pause. The "Chest leads V1–V6" tab lists each scenario's ECG findings. A short quiz waits at the bottom of the page.

Keyboard: Space play/pause · ← / → step through phases · 1–8 jump to a phase; every slider also works with the arrow keys.

About the model: the heart uses the Z-Anatomy atlas mesh (CC BY-SA, modified) and an original 2D drawing; pressures, volumes, ECG and heart sounds come from an idealized teaching model whose timing corrections are documented. The lab is built for physiology teaching; it is not patient-specific and is not a diagnostic or clinical decision tool.

The realistic heart: the atlas heart moves on the shared clock, its atria and ventricles follow the model's volume curves and its valves open and close with the modelled valve state. X-ray makes the walls translucent to show the valves, papillary muscles and chords. Colours follow textbook conventions (left heart warm red, right heart cooler, valve tissue ivory, pulmonary trunk blue); the colour-safe palette also separates the sides by brightness, the key marks synthesized parts, and Original atlas restores uniform colours. Conduction shows the activation wave spreading over the walls and the conduction system; Filling shows the blood in the chambers and a jet through each valve (in mitral regurgitation, a jet back into the left atrium); Blood flow shows streaks of blood moving from the veins through the atria and open valves into the great arteries, faster through narrow openings. Motion, paths and jets are teaching illustrations, not measured wall mechanics or flow.

Reading the heart views: each chamber is drawn at the size its volume curve gives it, so the ventricles fill in diastole and empty in systole, and a dilated failing ventricle looks larger; in bundle branch block the blocked ventricle contracts later by the branch delay; valve leaflets swing with the modelled valve state. These are illustrations; read exact volumes, pressures and ejection fraction from the curves and readouts.

微信小程序码：心动周期 / WeChat mini program code: Cardiac Cycle
你还可以用微信扫一扫打开「心动周期」小程序，并点击右上角「···」将它添加到「我的小程序」，以后在微信里随时打开。在微信内打开本页时，长按小程序码即可识别。 You can also scan this code with WeChat to open the Cardiac Cycle (心动周期) mini program, then tap “···” at the top right and add it to “My Mini Programs” to reopen it any time in WeChat. If you are reading this page inside WeChat, press and hold the code to open it.