Relation between pulmonary artery dicrotic notch pressure and mean
pulmonary artery pressure in humans.
Chemla, F]denis, Jean-Louis H[acute]ebert, Catherine Coirault, Sergio
Salmeron, Karen Zamani and Yves Lecarpentier.
Denis Chemla, Jean-Louis H[acute]ebert, Catherine Coirault, Sergio
Salmeron, Karen Zamani and Yves Lecarpentier
APStracts 3:0154H, 1996.
It has been suggested that pulmonary artery pressure at the end of
ejection is close to mean pulmonary artery pressure, thus
contributing to the optimization of external power from the right
ventricle. We tested the hypothesis that dicrotic notch and mean
pulmonary artery pressure could be of similar magnitude in 15 men
(50+/-12 years) referred to our laboratory for diagnostic right and
left heart catheterization. Beat-to-beat relationships between
dicrotic notch and mean pulmonary artery pressure were studied i) at
rest over 10 consecutive beats; and ii) in five patients, during the
Valsalva maneuver (178 beats studied). At rest, there was no
difference between dicrotic notch and mean pulmonary artery pressures
(21.8+/-12.0 vs 21.9+/-11.1 mmHg). There was a strong linear
relationship between dicrotic notch and mean pressure i) over the 10
consecutive beats studied in each patient (mean r=0.93); ii) over the
150 resting beats (r=0.99); and iii) during the Valsalva maneuver in
each patient (r=0.98-0.99) and in the overall beats (r=0.99). The
difference between dicrotic notch and mean pressure was -0.1+/- 1.7
mmHg at rest and -1.5+/-2.3 mmHg during the Valsalva maneuver.
Substitution of the mean pulmonary artery pressure by the dicrotic
notch pressure in the standard formula of the pulmonary vascular
resistance (PVR) resulted in an equation relating linearly end
-systolic pressure and stroke volume. The slope of this relation had
the dimension of a volume elastance Epa (mmHg/ml), a simple estimate
of Epa being obtained as 1.06 PVR/T, where T is duration of the
cardiac cycle. In conclusion, dicrotic notch pressure was of similar
magnitude than mean pulmonary artery pressure. These results
confirmed primary hypothesis and indicated that human pulmonary
artery can be treated as if it is an elastic chamber with a volume
elastance Epa=1.06 PVR/T.
Received 11 December 1995; accepted in final form 2 April 1996.
APS Manuscript Number H1147-5.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 23 April 96