ECHONOMY
Tools for Echocardiographic Calculations
Muhamed Saric, MD, PhD
New York University


Purpose

To
estimate pulmonary artery wedge pressure (PAWP) from mitral blood and annular tissue
Doppler velocities in early diastole. 
Technical Hints

Mitral annular e' velocity can be
measure at either medial (septal) or lateral annulus in the apical 4chamber
view. However, bear in mind that published data on E/e' ratio (LAP normal if
E/e' < 8; LAP elevated if E/e' > 15) are based on the medial e'
velocity. 
Calculator

Peak mitral inflow E velocity: 

cm/sec 
Peak mitral annular e' velocity: 

cm/sec 


Answers

E/e' ratio: 





Mean PAWP
(by full regression formula) 

mm Hg 
Mean PAWP
(by shortcut formula) 

mm Hg 



Interpretation 
E/e' Ratio 
Mean PAWP
(descriptive) 
Mean PAWP
(mm Hg) 

< 8 
Normal 
< 12 

8  15 
Indeterminate 
Any value 

> 15 
Elevated 
> 12 


Formulas
Full regression equation formula: PAWP
= 1.9 + 1.24 * E/e' Shortcut
formula: PAWP = 4 + E/e' 
Reference

Nagueh SF, Middleton KJ, Kopelen
HA, Zoghbi WA, Quinones MA. Doppler tissue imaging: a noninvasive technique
for evaluation of left ventricular relaxation and estimation of filling
pressures.
J Am Coll Cardiol 1997; 30:152733. 