Shortening versus isometric contractions in isolated human failing and non-failing left ventricular myocardium: dependency of external work and force on muscle length, heart rate and inotropic stimulation

Cardiovascular Research
C HolubarschH Just

Abstract

For reasons of simplicity, studies on isolated human myocardium have been conducted using exclusively isometric contractions, although positive inotropic interventions may differently influence force development, extent of shortening and myocardial work performance. We investigated human left ventricular failing and non-failing preparations comparing isometric versus isotonic, i.e., shortening contractions. (1) When muscle length is increased from 90% to 100% lMAX, peak developed force increases by 36% and 43% (p < 0.05) in non-failing and failing human left ventricular myocardium, respectively. Maximum performed work increases similarly in non-failing but decreases in failing myocardium. It can be shown that this discrepancy is due to significantly higher resting tension and does not present an insufficient intrinsic shortening capacity in failing myocardium. (2) When stimulation rate is increased from 0.5 to 2.0 Hz, isometric force increases significantly by 59% in non-failing and decreases by 27% in failing myocardium, whereas maximum performed work increases by 98% and decreases by 46%, respectively. (3) Pharmacological positive inotropic interventions by 7.2 mM calcium (n = 9), 3 x 10(-8) M isoproterenol (n = 7), 3 x 10(-8...Continue Reading

Citations

Mar 10, 1999·Progress in Biophysics and Molecular Biology·S C Calaghan, E White
Dec 15, 2007·Cardiovascular Research·Laurin M HanftKerry S McDonald
Oct 19, 2010·Cardiovascular Research·Steven A NiedererNicolas P Smith
Apr 21, 2009·American Journal of Physiology. Heart and Circulatory Physiology·Subash C GuptaPaul M L Janssen
Feb 1, 2003·European Journal of Heart Failure·Barry GreenbergSergio Perrone
Aug 24, 2013·Journal of Healthcare Engineering·Diana MassaiUmberto Morbiducci
Feb 4, 2010·Molecular and Cellular Endocrinology·Yun-Ying WangZhi-Bin Yu
Jan 15, 2015·Stem Cells and Development·Christiaan C VeermanMilena Bellin
Sep 26, 2003·Current Opinion in Critical Care·Andreas LehmannJürgen Kirchner
Dec 25, 2003·American Journal of Physiology. Heart and Circulatory Physiology·David G SoergelAnne M Murphy
Oct 30, 2019·Birth Defects Research·Nicola A PhilbrookLouise M Winn
May 23, 2017·Frontiers in Cell and Developmental Biology·Gaetano J Scuderi, Jonathan Butcher
Feb 20, 2020·The Journal of Physiological Sciences : JPS·Nathalie A Balakina-VikulovaLeonid B Katsnelson
Aug 4, 2009·American Journal of Physiology. Heart and Circulatory Physiology·Lucía RomeroBlanca Rodríguez
Nov 25, 2020·Journal of Biomedical Materials Research. Part B, Applied Biomaterials·Rui ZhangFeng Lan
Jul 28, 2020·Progress in Biophysics and Molecular Biology·Francesca MargaraBlanca Rodriguez
Aug 16, 2005·International Journal of Cardiology·Sergio V Perrone, Edgardo J Kaplinsky
Oct 23, 2019·ACS Biomaterials Science & Engineering·Marita L RodriguezMarc N Hirt

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