Myocardial perfusion and oxidative metabolism mismatch during
inotropic stress in cad patients with normal contractile
function.
Janier, Marc F., Xavier Andr[acute]e-Fouet, Patricia Landais, Marie
Claude Gr[acute]egoire, Franck Lavenne, Juventino Amaya, Catherine
Mercier, Jacques Machecourt, and Luc Cinotti.
Centre d'Exploration et de Recherche M[acute]edicale par Emission
de Positons (CERMEP), Universit[acute]e Claude Bernard Lyon I,
FRANCE
APStracts 3:0009H, 1996.
Using 11C-acetate, PET permits exploration of myocardial perfusion
(MBF) and oxidative metabolism (MVO2) coupling. PET imaging was
performed at rest and under dobutamine infusion in 8 normal subjects
and 10 patients with significant single vessel left anterior
descending (LAD) stenosis (>70%) and normal regional left
contractile function at rest. Rest MBF and MVO2 were similar in
remote and LAD regions of normal subjects and patients. During
dobutamine infusion, MBF and myocardial flow reserve were lower in
LAD regions of patients compared to remote regions (MBF: 1.49+/-0.42
and 2.06+/-0.57 ml.g-1.min-1, p<0.01; reserve: 1.73+/-0.59 and
2.14+/-0.47, p<0.01, respectively), while MVO2 expressed as
kmono and metabolic reserve were similar (kmono: 0.106+/-0.021 vs
0.107+/-0.017 min-1; reserve: 1.88+/-0.32 vs 1.98+/-0.37,
respectively). This is the first human study showing that, in normal
contractile regions at rest but perfused by stenosed artery, a
disparate rise in oxidative metabolism relative to the rise in
myocardial perfusion occurs during an increased cardiac work induced
by dobutamine. This flow-metabolism uncoupling probably reflects an
increase in O2 extraction.
Received 16 August 1995; accepted in final form 12 December 1995.
APS Manuscript Number H775-5.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 22 January 96