Cardiac tamponade

Source: saved session 01a13959-7cbf-7486-8848-e24365d67d7f, October 14, 2026.

The original detailed write-up is preserved verbatim below. Desktop paths and verification claims refer to that original session, not this import. Educational material only; not a clinical protocol or medical device. Clinical statements, diagnostic thresholds, and treatment recommendations have not been independently verified during import. Original model assumptions and limitations are preserved; independent clinical review is required before teaching or patient-care use.

I built the tamponade figure as an interactive page. Open ~/Desktop/anatomy-tamponade/tamponade-light.html (a dark version, tamponade.html, is beside it).

The figure is a bench model of the heart in its sac. A rigid frame is the fibrous pericardium. Inside it, in a row, sit a fluid bladder (the effusion), the right-ventricle bellows, a floating septum plate and the left-ventricle bellows. A stiff spring at the far end lets the frame give a little, then go solid. That's the sac's J-shaped pressure–volume curve.

• Syringe on the bladder: pericardiocentesis.
• Dial: pericardial pressure (Pp), with a red band from 15 to 25 mmHg.
• Column on the left: venous pressure (CVP, standing in for JVP).
• Scale along the base: volume, one tick per 10 mL.

Controls:

• Hover left to right to set the effusion from 25 to 220 mL.
• Click, or press Space, to drain 60 mL with the syringe.
• Arrow keys step 10 mL (Shift for 50).
• Left alone, it runs a 22-second loop: normal, effusion builds, a tap, then it clears.

Numbers from the model. These are teaching values tuned to textbook ranges, not patient data, and the beats play at half speed.

Pressures are in mmHg. As the effusion grows:

• Venous pressure climbs to just above Pp, so diastolic pressures roughly equalise.
• Stroke volume falls and the heart rate rises.
• Pulsus paradoxus goes over 10 mmHg from about 130 mL. On inspiration the right bellows takes more room, the septum shifts left and left stroke volume drops.
• Draining 60 mL at 210 mL drops Pp from 14 to 9 mmHg and lifts stroke volume from 26 to 45 mL. That's the steep end of the J-curve.

I capped the slider at 220 mL. Past that, pulsus fell back below 10 in the model. That comes from a minimum stroke volume I set, not from real physiology.

Checks:

• Loose lines: the skill's check found none, in both themes, at rest, mid-beat, at 220 mL and after a tap.
• Rendering and behaviour: screenshots at desktop and phone width came out clean, with no console errors. Reduced-motion mode shows a still frame at end of filling.
• Bug found and fixed: a 4× close-up showed the syringe's clamp band painted over the barrel, so I split the barrel around it.

I didn't run the skill's geometry audit; it's meant for figures with pipes and turned parts, and this one has none. Files are in ~/Desktop/anatomy-tamponade/, outside your repo:

• tamponade-light.html
• tamponade.html
• build.mjs (node build.mjs --light rebuilds)
• preview-light.png
• preview-dark.png