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

PAWP by E/e'

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 4-chamber 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 short-cut 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'

 

Short-cut 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; 30:1527-33.