PV Loop & EF / Stroke Work Laboratory

Set contractility, diastolic stiffness, arterial load and filling pressure to observe how the pressure-volume loop, Frank–Starling cardiac function curve, and 3D EF and stroke work surfaces respond in unison.

(a) Pressure–Volume Loops

EDPVR ESPVR Ea

(b) Frank–Starling & SW Function

Stroke work (left) PVAiso (right) Hover point to trace loop

(c) 3D Ejection Fraction Landscape

Ees vs α → EF (%) · Drag to rotate

(d) 3D Stroke Work Landscape

Ees vs α → SW (mmHg·mL) · Drag to rotate
Ventricle State EDP EDV ESV SV EF BP Ea Ea/Ees SW PVAiso CO
mmHg mL mL mL % mmHg mmHg/mL mmHg·mL mmHg·mL L/min

Biophysical Coupling: Time-varying elastance model P(V,t) = e(t)·Ees·(V−V0) + (1−e(t))·β·(e^(α(V−V0)) − 1). Activation e(t) rises smoothly to 1 at end-systole and relaxes with time constant τ. The ventricle fills from the left atrium through a mitral resistance (Rmv) and ejects into a 3-element Windkessel (Zc, R, C). The Frank–Starling curve sweeps filling pressure from 2 to 30 mmHg; each point represents the area of one steady-state loop. The 3D surfaces map EF and stroke work across contractility (Ees) and diastolic stiffness (α) with arterial load held constant.