Cardiovascular mechanics
This model isolates how preload, afterload, and contractility shape one ventricular beat. Read the circulation chapter's discussion of cardiac output, then use the controls to test the relationships rather than memorizing them.
Read the Cardiac Pump chapterLive model
Cardiac Output & Frank-Starling
Change one ventricular condition and watch the pump respond. Start with preload, then compare what happens when the ventricle faces more afterload or contracts more strongly.
Each control is relative to a baseline of 100%. Heart rate is held at 70 beats/min so the effect of ventricular mechanics stays visible.
Stroke volume
105 mL
Cardiac output
7.3 L/min
Ejection fraction
66%
MAP
87 mmHg
One-beat volume loop
Simplified ventricular volumes
Estimated oxygen delivery
1470 mL/min
Read the change
Move a control to see which part of the beat changes first.
Teaching model, not a clinical calculator. The relationships are intentionally simplified to make the mechanics visible: cardiac output = stroke volume × heart rate.