Electromechanical properties of Purkinje fiber strands isolated from human ventricular endocardium

The Journal of Heart and Lung Transplantation : the Official Publication of the International Society for Heart Transplantation
Fan-Yen LeeCheng-I Lin

Abstract

Abnormalities in the regulation of intracellular Ca2+ were observed in cardiac cells obtained from failing human hearts. However, the electromechanical properties and pharmacologic responses of human ventricular Purkinje fibers have not been well characterized. Strands of free-running Purkinje fibers and/or trabecular muscle fibers with a diameter of around 1.5 mm were removed from the endocardial surface of ventricles obtained from 16 transplant recipient hearts. Action potential (AP) was detected by conventional microelectrode techniques and twitch force by a force-displacement transducer. The human Purkinje fiber strands as revealed by histologic examination were composed of Purkinje cells and the surrounding ventricular muscle cells. In well-polarized Purkinje fibers (mean +/- SE of maximum diastolic potential [MDP] = -85 +/- 1 mV) showing fast-response AP (Phase 0 Vmax >100 V/sec), the cardiotonic agents isoproterenol and strophanthidin (1 to 2 micromol/liter) accelerated the slope of diastolic depolarization and induced delayed afterdepolarization but not spontaneous APs. Steady-state contraction and the post-rest potentiation of contraction (PRPC) were similar in both Purkinje fibers and ventricular muscles, but inotropi...Continue Reading

References

Apr 1, 1992·Cardiovascular Research·M VassalleC I Lin
Mar 7, 1980·European Journal of Pharmacology·C I Lin, M Vassalle
Jun 2, 1995·International Journal of Cardiology·C Y ChangC I Lin
May 8, 1993·Lancet·A L Waldo, A L Wit
Sep 1, 1993·Journal of Molecular and Cellular Cardiology·D M BersL V Hryshko
Apr 6, 1999·Trends in Cardiovascular Medicine·R G GourdieT Mikawa
Apr 12, 2003·Clinical and Experimental Pharmacology & Physiology·Jeng WeiCheng-I Lin

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Citations

May 6, 2009·Philosophical Transactions. Series A, Mathematical, Physical, and Engineering Sciences·Philip StewartHenggui Zhang
Jan 20, 2016·Nature Communications·George EngGordana Vunjak-Novakovic
Aug 2, 2016·Clinical Medicine Insights. Cardiology·Bijay LimbuMakarand Deo

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