Spike duration/Field potential duration (FPD) calculation

Hello Thomas,

I'm using Cardio2D 2.0.2.0 and Cardio2D+ analyzer 2.0.2.0. I was wanting to know how one could calculate the FPD from the information listed for each channel in the result file (.c2r - minimum, maximum rise times with timestamp in microseconds). As a preliminary method, I directly subtracted MinTS from MaxTS and obtained an interval that was too small for action potential duration of a cardiomyocyte (I got values ranking from 2-8 ms when the FPD that I should obtain ranges from 200-400ms which is the characteristic APD of a cardiomyocyte). It would be great if you help me out by indicating what quantities should I consider in order to obtain the correct FPD duration from the result file of each recording.

Thanks in advance,

Shwetha

Dear Shwetha,

please update your C2D software ;-) We have version 2.2.3 available for download from our homepage.

The detection timestamps all refer to the depolarisation peak (minimum, maximum, time of maximal slope).
To obatin FPD we have added a QT-Analysis module to Cardio2D+

Greetings

Thomas

http://download.multichannelsystems.com/download_data/software/Cardio2D+/Cardio2D+_2.1.3.exe
http://download.multichannelsystems.com/download_data/software/Cardio2D/Cardio2D_2.2.3_Full.exe

Hello Thomas,

I downloaded the latest version of cardio2D (I already was using the latest version of the cardio2D+). I played around with the QT Analyzer tab and could not understand a few things. After re-analyzing the raw data files with the QT Analyzer and HB averager on (with desired paramters), I see that the QT analyzer window shows only two field potentials per channel and displays the QT interval beside it (is this is the Field potential duration also ?) . If I look at the resultant result file (.c2r), I see that after every channel data (under ch<ID>ch) the Na peaks and QT interval count is displayed and in my file it specifically shows "QTinterval = 1" for all channel IDs. Is that right? I apologize if I am asking some basic questions! (just that I am new to this plugin and don't quiet follow). I read the manual and still could not clearly understand how it works. It would be great if you could elucidate some details of it.

Thanks in advance,
Shwetha

Dear Shwetha,

a value of 1 is indeed indicating a not succesfull detection of the QT duration in the result file.
I suggest you try to adjust the settings for detection and QT parameters.

To see how it looks in the result file when a value is detected you can just manually drag the line to
QT max / end.

Thomas