- Selected Pics
- Project Aims
- Background
- Videos
- Installation
- Building And Running
- Simulation Setup File
- Simulation Runtime Controls
- Changelog
- License
- Contributing Authors
- Funding Sources
- Acknowledgements
- References
Our project has several key objectives. Firstly, we aim to utilize N-body techniques to develop an interactive model of the left atrium. This model will allow users to manipulate various parameters in real-time, facilitating the induction and observation of common arrhythmias.
Secondly, we seek to create a training and study tool for electrophysiologists, researchers, and medical students. By accurately simulating left atrial arrhythmias and their treatment using simulated ablations, the model will serve as a valuable educational resource, enhancing understanding and skill development in this critical medical field.
Additionally, the project aims to advance research in electrophysiology by providing a platform for exploring novel treatment strategies and studying arrhythmia mechanisms. This could lead to new insights and innovations in the field, ultimately benefiting patients with cardiac arrhythmias.
In summary, the project's objectives include developing a cutting-edge model for arrhythmia simulation, providing an advanced training tool for medical professionals, and advancing research in electrophysiology.
Heart disease and strokes rank among the leading causes of death globally [1,2]. Supraventricular Tachycardia (SVT) significantly contributes to strokes, heart failure, and, in some cases, acute myocardial infarction [3-5]. Therefore, reducing SVT occurrence is crucial in our efforts to promote healthier lives free of cardiovascular diseases and strokes.
SVT encompasses all cardiac arrhythmias originating above the ventricles. This abnormal heartbeat can disrupt the natural synchronization between the atria and ventricles, causing blood to stagnate in the left atrium (LA) and forming potentially lethal blood clots known as mural thrombi [6]. These clots can dislodge and travel to the brain or coronary arteries, leading to a stroke or heart attack, as seen in individuals with atrial fibrillation (AF) who face a five-fold increased stroke risk [7].
Normally, the sinus node acts as the heart's pacemaker, generating an electrical impulse that dictates the heart's rhythm. Ectopic electrical impulses can disrupt this rhythm, causing the atria to flutter or beat out of sync with the ventricles [8].
While SVT can often be controlled with medication and lifestyle changes, some drugs can be challenging to tolerate, and certain effective medications can have hepatotoxic effects [9]. Catheter ablation, though more invasive, has proven to be the most efficacious and safest method for treating recurring SVT [10-13].
Advancements in radiofrequency (RF) catheter ablation and electro-anatomical mapping have enabled doctors to perform procedures on beating hearts that were once thought impossible [14,15]. However, much remains unknown about the causes of heart arrhythmias and how to treat them using RF catheter ablation [16]. A computer model of the LA, such as the one we have developed, can assist doctors, researchers, and medical students in rapidly and inexpensively testing ideas and observing outcomes.
The LA was chosen for modeling due to its role in complex arrhythmias [17-20]. Our model simulates both electrical and mechanical activity, allowing users to adjust parameters at the muscle level and introduce ectopic events. These tools enable users to induce arrhythmias in the LA that can be eliminated through simulated ablations, all in an interactive simulation setting.
Video 1-D Base: https://youtu.be/1LfkSLHCras
Video 2-D Base: https://youtu.be/uiBhadBPQuk
Video 2-D Reentry: https://youtu.be/9or9AD9T4vQ
Video 3-D Base: https://youtu.be/mIRA23GSZKs
Video 3-D Micro-reentry: https://youtu.be/9KuRWVdBDR0
Video 3-D Higher Node Count: https://youtu.be/SaPKsIT6DkM
Video LA Base: https://youtu.be/9QzJhKyeVGc
Video LA PV Flutter: https://youtu.be/E1mbqbofrDo
Video LA Micro-reentry: https://youtu.be/qZ7-WLGbyLQ
Video LA Roof Flutter: https://youtu.be/LkOr0d9mS2c
Video Realistic LA: https://youtu.be/G_ZcHeLRRjc
- This simulation requires a CUDA-enabled GPU from Nvidia. Click here for a list of GPUs.
| *Note: These are guidelines, not rules | CPU | GPU | RAM |
|---|---|---|---|
| Minimum: | AMD/Intel Six-Core Processor | Any CUDA-Enabled GPU | 16GB DDR4 |
| Recommended: | AMD/Intel Eight-Core Processor | RTX 3090/Quadro A6000 | 32GB DDR5 |
Disclosure: This simulation only works on Linux-based distros currently. All development and testing was done in Ubuntu 20.04/22.04
Install Nvidia CUDA Toolkit:
sudo apt install nvidia-cuda-toolkit
Install Mesa Utils:
sudo apt install mesa-utils
Navigate to the cloned folder and run the following command to build and compile the simulation:
./compile
After compiling, run the simulation:
./run
Length is in millimeters (mm)
Time is in milliseconds (ms)
Mass is in grams (g)
You can start a new run using the nodes and muscles files, or you can continue a previous run.
NodesMusclesFileOrPreviousRunsFile = 0, run from the selected nodes and muscles file
NodesMusclesFileOrPreviousRunsFile = 1, run from a previous run file
If you selected 0, then you must set
InputFileName = ***;
to the name of the nodes and muscles file you want to run from the list below.
{Line11, Circle24, CSphere340, CSphere5680, IdealLeftAtrium13.0KNotTriangle, LeftAtriumRealRemovedAppendage}
If you selected 1, then you must set
PreviousRunFileName = ***;
to the name of a previous run file you saved in the PreviousRunsFile folder. The three previous run files listed below
are already placed in this folder to use as demos.
{PVFlutterDemo, MicroReentryDemo, RoofFlutterDemo}
You can set the size of the nodes and muscles with the
LineWidth = ***;
NodeRadiusAdjustment = ***;
Colors to help distinguish between simulation events can all be customized at the end of the setup file.
Note: This only affects the viewing of the simulation; no actual functionality is changed with these parameters.
Myocyte Force Per Mass strength = 596.0 mm/ms^2
BloodPressure = 80.0; millimeters of mercury converted to g/(mm*ms*ms) in the program.
MassOfAtria = 25; g
RadiusOfAtria = 17.8; mm
BaseMuscleRelaxedStrength = 2.0; This is just a force that helps the model keep its shape.
BaseMuscleCompresionStopFraction = 0.7 This only lets a muscle fiber reduce its length by 30%
BeatPeriod = 1000.0; (ms)
MaxNumberOfperiodicEctopicEvents = 50; This just sets an upper limit to the number of ectopic beats a simulation can have.
Note: ectopic beats are extra pulse nodes that the user sets in an active simulation. Ectopic triggers are single events
stimulated by mouse clicks.
The above are typical values and are all changeable in the setup file. These values are read in at the start of a simulation.
They are not changeable once the simulation starts.
BaseMuscleContractionDuration = 200.0; (ms)
BaseMuscleRechargeDuration = 200.0; (ms)
BaseMuscleConductionVelocity = 0.5; (mm/ms)
The above are typical values read in from the setup file at the start of a simulation. These values are all changeable in an active simulation.
PrintRate = 100.0; How often the program prints new information to the terminal screen.
DrawRate = 1000; How often the program draws a new simulation picture.
Dt = 0.001; How many Leap-Frog iterations are done for each ms of simulation time.
Refer to the changelog for details.
- This code is protected by the MIT License and is free to use for personal and academic use.
- Bryant Wyatt (PI)
- Gavin McIntosh
- Avery Campbell
- Melanie Little
- Leah Rogers
- Derek Hopkins
- Zachary Watson
- Brandon Wyatt
This research was supported by the NVIDIA cooperation’s Applied Research Accelerator Program. Student support was provided by Tarleton State University’s Presidential Excellence in Research Scholars and the Bill and Winnie Wyatt Foundation.
We would like to thank Tarleton State University’s Mathematics Department for use of their High-Performance Computing lab for the duration of this project.
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