Luo-Rudy Dynamic (LRd) Model for Ventricular Cells
While the Beeler-Reuter applet and the Luo-Rudy-I applet show first generation ionic ventricular cell models, this LRd is a second generation model that includes formulation for most of the sarcolemmal currents, pumps and exchangers. The model implements cell compartmentalization (myoplasm, junctional and nonjunctional sarcoplasmic reticulum), Ca2+ buffers in the myoplasm (troponin, calmodulin) and in the junctional sarcoplasmic reticulum (calsequestrin), and calcium-induced Ca2+ release. It takes into account myoplasmic concentration changes of Na+ and K+ as well as Ca2+ concentration changes in all three compartments.
For more detailed information visit Dr. Rudy's lab CBRTC and the official LRd model web site
- The Start button initiates the applet.
Example 1 is displayed by default. It shows the voltage trace of a 1.2 second simulation of a single cell paced at a BCL (basic cycle length) of 200ms.
Use the Examples menu to choose between any of the other three examples.
Example 2: Displays Voltage and the gates f, x1, and xr for a cell paced at a BCL of 180ms. Time of simulation is 1s but only 550 ms are displayed.
Example 3: Displays Voltage and Calcium transient [Ca] for a 2.16s simulation with a BCL of 90 ms.
Example 4: Displays Voltage, [Ca],[Na] and [K] internal concentrations for a 10s simulation for a cell paced at a BCL of 150 ms.
Besides the examples, one can simulate at any time and any BCL for any amount of time.
Just enter the BCL in the BCL text field and press enter or click Replot.
The simulation time can be changed using the Time text field.
To zoom any particular portion of the simulation, indicate the starting plotting time using the Start Time text field and the
final time using the Final Time text field, then press enter or click on the Zoom buton.
Any of the 10 gate variables - m, h, j, d, f, xs1, xs2, xr, b, and g - can be plotted by using the check boxes. Values go from 0 to 1 but they are normalized to show
on the voltage plot.
The [Ca], [Na] and [K] concentrations can also be viewed by selcting their check boxes. They are also normalized to the voltage plot.
The action potential duration (APD) of the last activation is always shown in the bottom-right corner.