Model number


The Modified Luo-Rudy Dynamic Model of the Mammalian Ventricular Myocyte.


 The Luo-Rudy Dynamic (LRd) Model of the Mammalian Ventricular Myocyte. This model describes 
 the mammalian cardiac ventricular action potential in a single cell in guinea pigs. Along 
 with the membrane sodium and potassium currents, the model focuses on processes that regulate 
 intracellular calcium and depend on its concentration. The figure in this section shows all 
 the channels and currents in the modeled single cell. The “C”code 
 was adapted, Illustrative Diagram block for block,into JSIM's Mathematical Modeling Language (MML). 
 The code was substantially modified, converting many of the expressions into ordinary 
 differential equations. Rapid equilibria have been transformed into “fast” ODE's in order to 
 avoid iterative procedures, complex polynomial solutions, etc. “C” subroutines for currents 
 were converted to ordinary differential equations where necessary. Stimulus was replaced by 
 JSIM's external function (extern real st(t);). Information pertaining to step size was removed 
 and replaced by JSim's realDomain t. Recording of maximum excursions on a beat by beat basis 
 was deleted. Double declarations (“C” construct) were replaced by real declarations 
 (JSIM's MML construct which are double precision variables.) The “C” subroutines were converted 
 to inline code and placed earlier in the structure. Fast equilibria were were replaced by ODE's 
 to avoid solving quadratic and cubic equations–the special innovation of the LR model. Any 
 errors contained in the code are not the fault of the original authors.

fig 1


Figure: This figure is the action potential (thin black line) when stimulated every 300 msec by the stimulus current (thick red line) having duration 1 msec and amplitude 35 uA/cm^2.


The equations for this model may be viewed by running the JSim model applet and clicking on the Source tab at the bottom left of JSim's Run Time graphical user interface. The equations are written in JSim's Mathematical Modeling Language (MML). See the Introduction to MML and the MML Reference Manual. Additional documentation for MML can be found by using the search option at the Physiome home page.

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  • Luo CH, Rudy Y.;A model of the ventricular cardiac action potential. Depolarization, repolarization, and their interaction, Circ Res 1991;68:1501-1526
  • Luo CH, Rudy Y.; A dynamic model of the cardiac ventricular action potential. II. Afterdepolarizations, triggered activity, and potentiation, Circ Res 1994;74:1097-1113
  • Zeng J, Laurita KR, Rosenbaum DS, Rudy Y; Two components of the delayed rectifier K+ current in ventricular myocytes of the guinea pig type. Theoretical formulation and their role in repolarization.,Circ Res 1995;77:140-152
  • Zeng J, Rudy Y.; Early afterdepolarizations in cardiac myocytes: mechanism and rate dependence., Biophys J 1995;68:949-964
  • Shaw RM, Rudy Y.; Electrophysiologic effects of acute myocardial ischemia: a theoretical study of altered cell excitability and action potential duration, Cardiovasc Res 1997;35:256-272
  • Viswanathan PC, Shaw RM, Rudy Y.; Effects of IKr and IKs heterogeneity on action potential duration and its rate dependence: a simulation study., Circulation 1999;99:2466-2474
  • Viswanathan PC, Rudy Y.; Pause induced early afterdepolarizations in the long QT syndrome: a simulation study., Cardiovas Res 1999;42:530-542
  • Clancy CE, Rudy Y.; Linking a genetic defect to its cellular phenotype in a cardiac arrhythmia. Nature 1999;400:566-569
  • Viswanathan PC, Rudy Y.; Cellular arrhythmogenic effects of congenital and acquired long-QT syndrome in the heterogeneous myocardium. Circulation. Circulation 2000;101:1192-1198
  • Faber GM, Rudy Y.; Action potential and contractility changes in [Na(+)](i) overloaded cardiac myocytes: a simulation study. Biophy J 2000;78:2392-2404
  • Beatriz Trénor, Lucía Romero, José María Ferrero (Jr), Javier Sáiz, Germán Moltó, José Miguel Alonso; Vulnerability to Reentry in a Regionally Ischemic tissue. A simulation Study, (in press)
Key terms
cardiac action potential
ionic currents
cell physiology

Please cite in any publication for which this software is used and send one reprint to the address given below:J. B. Bassingthwaighte, Department of Bioengineering, University of Washington, Seattle WA 98195-5061.

Model development and archiving support at provided by the following grants: NIH U01HL122199 Analyzing the Cardiac Power Grid, 09/15/2015 - 05/31/2020, NIH/NIBIB BE08407 Software Integration, JSim and SBW 6/1/09-5/31/13; NIH/NHLBI T15 HL88516-01 Modeling for Heart, Lung and Blood: From Cell to Organ, 4/1/07-3/31/11; NSF BES-0506477 Adaptive Multi-Scale Model Simulation, 8/15/05-7/31/08; NIH/NHLBI R01 HL073598 Core 3: 3D Imaging and Computer Modeling of the Respiratory Tract, 9/1/04-8/31/09; as well as prior support from NIH/NCRR P41 RR01243 Simulation Resource in Circulatory Mass Transport and Exchange, 12/1/1980-11/30/01 and NIH/NIBIB R01 EB001973 JSim: A Simulation Analysis Platform, 3/1/02-2/28/07.