iElastance

Ventricular–arterial coupling

Ees, Ea and VAC, in a single beat.

Cuff pressures · Standard echo · No catheter

Six values from the bedside give end-systolic elastance, arterial elastance and their coupling, with the pressure–volume diagram. Follow each patient over time and share a PDF report. Your cases stay on your device.

Try the demo Learn more
ES V0 EDV 050100 −50050100 Volume (ml) Pressure (mmHg)
Ees 1.3 mmHg/ml Ea 1.5 · VAC 1.2

Example: SBP 120, DBP 80 mmHg, EF 60%, SV 70 ml, PET 74, TET 265 ms

6bedside values, no catheter
3indices: Ees, Ea and VAC
10recent cases, each followed over time

Features

From the bedside to the report.

Built for intensive care, anaesthesia and cardiology, where coupling guides fluids, vasopressors and inotropes.

Single beat

Chen's non-invasive method: results update while you type, with checks on impossible values.

PV diagram

ESPVR, Ea line and stroke volume drawn from your values. Tap to read each point.

Cases over time

Baseline, after fluids, after a vasopressor: every measurement of a case, with trends.

PDF report

Results, diagram, table of measurements, trends, method and reference, ready to print or share.

Method

A published, transparent formula.

Chen CH et al. Noninvasive single-beat determination of left ventricular end-systolic elastance in humans. J Am Coll Cardiol 2001;38:2028–34 (PubMed).

ESP = 0.9 × SBP
tNd = PET / TET
ENd(avg) = Σ aᵢ · tNdⁱ (i = 0…7)
ENd(est) = 0.0275 − 0.165·EF + 0.3656·DBP/ESP + 0.515·ENd(avg)
Ees = (DBP − ENd(est)·ESP) / (SV · ENd(est))
Ea = ESP / SV    VAC = Ea / Ees

What you need

Systolic and diastolic cuff pressure; ejection fraction (Simpson); stroke volume (LVOT Doppler or volumes); pre-ejection and total ejection time from the LVOT pulsed Doppler with ECG. The app's guide shows where each value comes from.

The demo

Try it now, free.

The web version is a demo: try the calculator and an example PDF report. Nothing is stored.

  1. Create an account

    Free, for healthcare professionals. Confirm your email with a link.

  2. Try the calculator

    Enter six values, read the pressure–volume diagram and create an example PDF.

  3. Get the app

    To keep your cases and follow them over time on iPhone, iPad or Android.

Checking access…