Determinants of left ventricular preload-adjusted maximal power

Patrick Segers, Vincent Tchana-Sato, H Alex Leather, Bernard Lambermont, Alexandre Ghuysen, Jean-Michel Dogne, Patricia Benoit, Philippe Morimont, Patrick F Wouters, Pascal Verdonck, Philippe Kolh

Résultats de recherche: Contribution à un journal/une revueArticleRevue par des pairs

Résumé

Maximal left ventricular (LV) hydraulic power output (PWR(max)), corrected for preload as PWR(max)/(V(ed))(beta) (where V(ed) is the end-diastolic volume and beta is a constant coefficient), is an index of LV contractility. Whereas preload-adjusted maximal power (PAMP) is usually calculated with beta = 2, there is uncertainty about the optimal value of beta (beta = 1 for the normal LV and 2 for the dilated LV). The aim of this work is to study the determining factors of beta. The data set consisted of 245 recordings (steady state and vena cava occlusion) in 10 animals in an ischemic heart pig model. The occlusion data yielded the slope (E(es); 2.01 +/- 0.77 mmHg/ml, range 0.71-4.16 mmHg/ml) and intercept (V(0); -11.9 +/- 22.6 ml; range -76 to 39 ml) of the end-systolic pressure-volume relation, and the optimal beta-factor (assessed by fitting an exponential curve through the V(ed)-PWR(max) relation) was 1.94 +/- 0.88 (range 0.29-4.73). The relation of beta with V(ed) was weak [beta = 0.60 + 0.02(V(ed)); r(2) = 0.20]. In contrast, we found an excellent exponential relation between V(0) and beta [beta = 2.16e(0.0189(V(0))), r(2) = 0.70]. PAMP, calculated from the steady-state data, was 0.64 +/- 0.40 mW/ml(2) (range 0.14-2.83 mW/ml(2)) with a poor correlation with E(es) (r = 0.30, P
langue originaleAnglais
Pages (de - à)H2295-301
journalAmerican Journal of Physiology-Heart and Circulatory Physiology
Volume284
Numéro de publication6
Les DOIs
Etat de la publicationPublié - juin 2003

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