Copyright © 2001 Paolo Barbier

Calculated difference between the duration of the transmitral A wave (A, upper panel) and the pulmonary vein retrograde A wave (Ar, lower panel). 

Normal LV pre-a wave pressure: A - Ar > 0

Increased LV pre-a wave pressure (> 15 mmHg): A - Ar < 0 (Sensitivity= 85%, Specificity= 79%)

(Rossvoll O and Hatle LK, 1993)

Velocity calibration (distance between white dots) = 20 cm/sec 

AOP: Aortic pressure tracing
LAP: left atrial pressure tracing
LVP: left ventricular pressure tracing
a: left atrial peak a wave pressure
v: left atrial peak v wave pressure
x: left atrial x pressure trough
red arrow: pre-a wave pressure point