Pflügers Archiv - European Journal of Physiology

, Volume 455, Issue 6, pp 987–994

Parameters of ventricular contractility in mice: influence of load and sensitivity to changes in inotropic state

Authors

  • An Van den Bergh
    • Department of Cardiovascular Diseases, Division of Experimental Cardiac SurgeryKatholieke Universiteit Leuven
  • Willem Flameng
    • Department of Cardiovascular Diseases, Division of Experimental Cardiac SurgeryKatholieke Universiteit Leuven
    • Department of Cardiovascular Diseases, Division of Experimental Cardiac SurgeryKatholieke Universiteit Leuven
Cardiovascular System

DOI: 10.1007/s00424-007-0362-8

Cite this article as:
Van den Bergh, A., Flameng, W. & Herijgers, P. Pflugers Arch - Eur J Physiol (2008) 455: 987. doi:10.1007/s00424-007-0362-8

Abstract

We examined the relative usefulness of parameters to determine left ventricular contractility in mice invasively. The optimal parameter must be sensitive to changes in inotropy and insensitive to changes in loading. Furthermore, it should be able to confirm or reject the hypothesis of altered myocardial contractility after a limited number of experiments. Left ventricular function was assessed in closed-chest mice using a microtip pressure-conductance catheter at baseline and after increases in preload, afterload, or contractility. The parameters are differentially influenced by loading conditions and inotropic state. Only those parameters that could differentiate between basal and increased contractility with a power of 0.85 in ten or less experiments were considered useful. Ejection fraction, preload-recruitable stroke work (PRSW), and dP/dtmax/Ved could demonstrate the smallest changes in contractility. Stroke work, maximal power and dP/dtmax were most influenced by preload. End-systolic elastance, ejection fraction, and stroke work were afterload-dependent. Dividing the magnitude of the effect of inotropic stimulation to that of load changes gives an index for the usefulness for each parameter. A high ratio indicates that the change in parameter reflects inotropic rather than load change. This ratio was highest for PRSW, which seems to be the best parameter for judging contractility differences in mice.

Keywords

Myocardial contractionMiceVentricular functionHeart function tests

Copyright information

© Springer-Verlag 2007