A web-based calculator for estimating peak systolic pulmonary artery pressure (EPSPAP) from pulmonary artery acceleration time (PAAT) measured by Doppler echocardiography.
🔗 Live Demo: https://parameterz.github.io/PAAT-Thing/
Conventional echocardiographic estimation of pulmonary artery pressure relies on tricuspid regurgitation (TR) velocity. However:
- 25% of patients have insufficient TR for pressure estimation
- PAAT is measurable in 99.6% of patients
This calculator provides a validated alternative method for estimating pulmonary artery pressure when TR is absent or inadequate.
✅ Simple, single-input interface
✅ Validated formula from peer-reviewed research
✅ Automatic range validation (study range: 43-186 msec)
✅ Mobile-responsive design
✅ No installation required - pure HTML/JavaScript
- Obtain PAAT measurement from pulsed-wave Doppler of the main pulmonary artery
- Enter the PAAT value (in milliseconds)
- Click "Calculate EPSPAP"
- Review the estimated peak systolic pulmonary artery pressure
Formula:
log₁₀(EPSPAP) = -0.004(PAAT) + 2.1
Validation:
- Strong inverse correlation with TR-derived EPSPAP (r = -0.95)
- Excellent interobserver variability (r = 0.97)
- Validated in 371 patients across wide pressure range (19-102 mm Hg)
Yared K, Noseworthy P, Weyman AE, McCabe E, Picard MH, Baggish AL. Pulmonary Artery Acceleration Time Provides an Accurate Estimate of Systolic Pulmonary Arterial Pressure during Transthoracic Echocardiography. J Am Soc Echocardiogr. 2011;24:687-92.
https://doi.org/10.1016/j.echo.2011.03.008
- Pure HTML5/CSS3/JavaScript
- No dependencies or frameworks
- Works offline once loaded
- Compatible with all modern browsers
MIT License - feel free to use, modify, and distribute.
Questions or suggestions? Open an issue or submit a pull request!