J. Lisauskas et al., The relation of the peak doppler E-wave to peak mitral annulus velocity ratio to diastolic function, ULTRASOUN M, 27(4), 2001, pp. 499-507
Previous observations (Garcia et al, 1998; Sohn et al, 1997; Nagueh et al,
1997) indicate that mitral annulus velocity may be viewed as a "load-indepe
ndent" index of filling and that wedge pressure is linearly related to the
transmitral flow velocity (V-E) to mitral annulus velocity (V-MA) ratio (V-
E/V-MA) measured at maximum velocity. In healthy subjects, the mean value o
bserved for [V-E](max)/[V-MA](max) was 1:0.23 congruent to 4, No prior phys
iologic or physical explanation for the basis of, or for the magnitude of,
the ratio has been proposed. We propose a physiologic, model-based, quantit
ative explanation for these observations and test our simplified model's pr
ediction in an invasive (n = 30) and noninvasive (n = 34) test groups of su
bjects. The simplified geometric model is based on the known constant volum
e (within a few percentage points) attribute of the four-chambered heart. A
ccordingly, left-atrial and left-ventricular volumes reciprocate so that th
eir sum is constant throughout the cardiac cycle. The model predicts that:
1. the ratio (V-E/V-MA) is a constant congruent to3 in healthy hearts; and
2, V-E/V-MA should be linearly proportional to left ventricular end-diastol
ic pressure (LVEDP), Model prediction was tested using V,and V-MA echocardi
ographic data from 34 subjects (noninvasive group), and simultaneous echoca
rdiographic and high-fidelity hemodynamic (LVEDP) data in 30 subjects (inva
sive group). Excellent agreement was observed between model prediction and
observed data. For the noninvasive (healthy) group, [V-E](max)/[V-MA](max)
= 4.20 +/- 1,11, For the invasive group, [V-E](max)/[V-MA](max) was observe
d to be linearly related to LVEDP, [V-E](max)/[V-MA](max) = 0.19 (LVEDP) 1.54, r = 0.92, Hence, [V-E](max)/[V-MA](max) is a legitimate flow-derived
index of diastolic function because it is a derivable consequence of the he
art's constant-volume pump attribute. (C) 2001 World Federation for Ultraso
und in Medicine & Biology.