Nav: Home

A 'virtual heart' to simulate arrhythmia

September 06, 2017

A group of researchers from MIPT and Ghent University (Belgium) has developed the first realistic model able to reproduce the complexity of the cardiac microstructure. The researchers hope that the model will help them better understand the causes of fibrosis which affects the onset of cardiac arrhythmias. Although the model is currently only able to simulate one layer of cardiac cells, electrical wave propagation observed in the simulations was the same as in the experimental tissues. The paper was published in the journal Scientific Reports.

Nina Kudryashova, a Ph.D. student at MIPT and a co-author of the study, comments: "The chances of developing arrhythmia tend to increase with age, which is partly due to fibrosis. Unfortunately, we can only observe a fully developed clinical picture and not the process of arrhythmia development itself. That is why we have proposed a mathematical model which is able to determine the factors responsible for the formation of different fibrosis patterns."

According to the World Health Organization, cardiovascular diseases account for the highest number of deaths globally. Around 40% of these deaths occur suddenly and are caused by arrhythmia, a group of conditions in which the heartbeat is irregular. Contractions of the heart are initiated by the propagation of electrical waves in cardiac tissue. Although the tissue is made up of different types of cells, it is cardiomyocytes (CMs) that perform the electromechanical function of the heart. In addition to CMs, cardiac tissue contains non-excitable cells, i.e., cells incapable of electrical excitation, such as fibroblasts (FBs). The formation of excess fibrous connective tissue is called fibrosis; it affects wave propagation and often leads to arrhythmia. Despite the fact that it is impossible to observe the stages of arrhythmia development/progression, computer modeling of cardiac tissue could provide new opportunities to study the relation between cardiac tissue morphology and arrhythmia development.

In order to build a reliable and accurate model, the researchers collected experimental data on cell shapes. For this purpose, cardiac cells, namely CMs and FBs, were cultured under different conditions. All in all, four cases were considered in the study: Non-interacting (isolated) cells with and without nanofibres and monolayers with and without nanofibres. When grown on a scaffold of nanofibers, the cells are forced to elongate in one direction, which allows a better reproduction of the texture of cardiac muscle tissue. As a result, the researchers obtained statistical data on the shapes of FBs and CMs and their interaction.

Valeriya Tsvelaya, a Ph.D. student and another co-author of the study, explains: "Since cardiac tissue cells are elongated along the fibrous substrate, the tissue exhibits anisotropy, which is when electrical waves propagate differently depending on the propagation direction. When wave propagation is directionally independent (such as in the case of non-nanofibrous monolayer substrates), isotropy is observed."

To reproduce the formation of cardiac tissue, the researchers took a mathematical model -- one that is widely applied to study tissue growth -- and optimized it using the collected experimental data. The model they obtained provided a detailed and accurate reproduction of cell shape parameters in each of the four cases. In order to observe excitation wave propagation, the researchers stimulated the cells in the culture with an electrode. They also imitated wave propagation in virtual cardiac tissue and discovered that the wave propagation pattern accurately reproduced the experimentally observed behavior for both isotropic and anisotropic cases. This means that the proposed model can indeed be used to study cardiac tissue properties and various risk factors for arrhythmias.

Attempts to simulate wave propagation in cardiac tissue had been made before, but those were simple models which did not reproduce the complexity of cell shapes. Besides, FBs in all the previously performed simulations were arranged in a random way, while in reality CMs and FBs are arranged in a pattern arising from the peculiarities of their interaction. In their model, the researchers considered both the shapes and the interaction between the cells, thus making their computer simulations more accurate and realistic.

"The model we proposed can predict the same wave propagation patterns we observed in our experimental samples, which means it can be used to help us learn to predict the probability with which a patient will develop arrhythmia. You just vary the conditions under which a tissue is formed and see what the chances of developing arrhythmia in this tissue are," explains Konstantin Agladze, head of the Laboratory of Biophysics of Excitable Systems at MIPT.

That said, the model is currently in the initial stage of development. There are a number of factors to be considered, such as cell migration, all of which can influence tissue development. Besides, the heart is three-dimensional while the model is two-dimensional, which means the researchers still need to work out how to make it 3-D. Achieving this will open up new possibilities of describing tissues in living organisms.
-end-


Moscow Institute of Physics and Technology

Related Arrhythmia Articles:

Pacemakers and other cardiac devices can help solve forensic cases
Pacemakers and other cardiac devices can help solve forensic cases, according to a study presented today at EHRA EUROPACE - CARDIOSTIM 2017.
Tenth year of data on cardiac arrhythmia treatment launched at European congress
The tenth year of data on cardiac arrhythmia treatment is being launched at EHRA EUROPACE - CARDIOSTIM 2017.
Common antibiotic azithromycin not linked to increased risk of abnormal heartbeat
The commonly used antibiotic azithromycin is not linked to an increased risk of ventricular arrhythmia, an often life-threatening rapid, irregular heartbeat, according to a large study published in CMAJ.
Ion treatments for cardiac arrhythmia
At the GSI Helmholtz Center for Heavy Ion Research was developed and tested a new method for a future treatment of cardiac arrhythmia.
Termination of lethal arrhythmia with light
A research team from the University of Bonn has succeeded for the first time in using light stimuli to stop life-threatening cardiac arrhythmia in mouse hearts.
Building a smart cardiac patch
Harvard researchers have created nanoscale electronic scaffolds that can be seeded with cardiac cells to produce a 'bionic' cardiac patch.
Cause of heart arrhythmia in adult muscular dystrophy clarified
An international joint research group found that the cause of heart arrhythmia in myotonic dystrophy was RNA abnormalities in the sodium channel in the heart, clarifying the symptom's mechanism.
Study compares manual versus robotic approach to treating dangerous heart arrhythmia
Whether ablation of the highest-risk heart arrhythmia is best handled by a robot or the hands of an electrophysiologist should be answered by an international comparison of the two.
ADHD medication linked to slightly increased risk of heart rhythm problems
Use of methylphenidate in children and young people with ADHD is associated with a slightly increased risk of abnormal heart rhythm (arrhythmia) shortly after the start of treatment, suggests research published by The BMJ today.
UPMC researchers shine light on common heart complication after lung transplantation
Cardiac arrhythmia is a common complication following lung transplantation, and one that has a significant negative impact on long-term patient survival.

Related Arrhythmia Reading:

Basic Arrhythmias (8th Edition)
by Gail Walraven (Author)

For all courses in basic or introductory cardiography


Focused coverage and realistic hands-on practice help students master basic arrhythmias
Basic Arrhythmias, Eighth Edition
, gives beginning students a strong basic understanding of the common, uncomplicated rhythms that are a foundation for further learning and success in electrocardiography. Concepts are presented in a flexible, progressive approach to allow for self-paced or classroom learning. Chapters cover basic... View Details


ECG Workout: Exercises in Arrhythmia Interpretation
by Jane Huff (Author)

Publisher’s Note:   Products purchased from 3rd Party sellers are not guaranteed by the Publisher for quality, authenticity, or access to any online entitlements included with the product.

Grasp the electrocardiography basics and identify arrhythmias accurately, with the freshly updated ECG Workout, 7th Edition.
 
Fully addressing the most common arrhythmias, this clearly worded text will take you step-by-step through expert ECG tracing interpretation methods, including differentiating among rhythm groups, equipment use, and management protocols.... View Details


Basic Arrhythmias (6th Edition)
by Gail Walraven (Author)

Newly revised edition of a BEST-SELLING EKG book! Revised and updated to include topics such as the use of pacemakers. A FREE in-book CD will give users an opportunity to practice in an interactive and fun environment. Appropriate for any student or practicing health care provider who needs to learn or review basic EKG or arrhythmia concepts.

View Details


Catheter Ablation of Cardiac Arrhythmias, 3e
by Shoei K. Stephen Huang MD (Author), John M. Miller MD (Author)

Whether you are in the lab or the office, stay current in the ever-evolving field of electrophysiology with Catheter Ablation of Cardiac Arrhythmias. Organized by type of arrhythmia, this simple yet comprehensive medical reference book provides detailed information on anatomy, diagnoses, mapping/ablation, and troubleshooting. The book also extensively covers the updated, basic concepts of transcatheter energy applications and currently available mapping/imaging tools for ablation.

Improve accuracy with assistance from advanced catheter mapping and... View Details


Basic Arrhythmias (5th Edition)
by Gail Walraven (Author)

Appropriate for any student or practicing health care provider who needs to learn or review basic EKG or arrhythmia concepts. This classic, best-selling book has been completely updated and revised to reflect the latest knowledge in the field. Now in full color, Basic Arrhythmias, Fifth Edition covers all the basics of arrhythmia interpretation and includes appendices on Clinical Implications of Arrhythmias, Cardiac Anatomy and Physiology, 12-Lead Electrocardiography, Basic 12-Lead Interpretation, and Pacemakers. View Details


Basic Arrhythmias, 7th Edition
by Gail Walraven (Author)

This classic, best-selling book has been completely updated and revised to reflect the latest knowledge in the field!  Basic Arrhythmias, Sevent Edition covers all the basics of arrhythmia interpretation and includes appendices on Clinical Implications, Cardiac Anatomy and Physiology, 12 Lead Electrocardiography, Basic 12 Lead Interpretation, and Pathophysiology of Arrhythmias. The author takes great care in presenting a difficult topic in an easy manner with a building block approach.  Some features to this updated edition include:

Over 600 practice... View Details


Electrophysiological Maneuvers for Arrhythmia Analysis
by George J. Klein (Author), Lorne J. Gula (Author), Peter Leong-Sit (Author), Jaimie Manlucu (Author), Allan C. Skanes (Author), Raymond Yee (Author), Paul D. Purves (Author)

It goes without saying that a correct arrhythmia diagnosis is a prerequisite to catheter ablation regardless of the presence of sophisticated mapping and imaging technologies. Electrophysiological maneuvers are fundamental to this process, and proper selection and interpretation of maneuvers constitute a core skill of the electrophysiologist. In this volume, we make the case that most maneuvers are fundamentally similar in principle and can be understood by appreciating a few basic physiological and anatomical principles. The art lies not in a comprehensive knowledge by rote of every maneuver... View Details


Arrhythmia Essentials, 2e
by Brian Olshansky MD (Author), Mina K Chung MD (Author), Steven M Pogwizd MD (Author), Nora Goldschlager MD (Author)

Concise, compact, fully-illustrated and easy to read, Arrhythmia Essentials, 2nd Edition provides detailed, practical information on recognizing and treating heart rhythm disturbances for clinicians with any level of expertise. The author team, led by renowned authority in cardiac electrophysiology, Dr. Brian Olshansky, guides you skillfully through the different types of arrhythmias and how they present on ECGs. You’ll find specific examples of each arrhythmia, numerous algorithms to facilitate an approach to arrhythmia diagnosis and management, updates on medical... View Details


ECG Workout: Exercises in Arrhythmia Interpretation (Huff, ECG Workout)
by Jane Huff RN CCRN (Author)

This outstanding text and workbook is the leading reference for students, practicing nurses, paramedics, and other health professionals learning ECG interpretation. Thoroughly updated with new figures and easy-to-follow text,  ECG Workout is an excellent guide to rhythm analysis that builds on the student's knowledge in a step-by-step fashion to broaden understanding of essential ECG concepts and hone the skills necessary to confidently and accurately interpret ECG waveforms. Coverage includes cardiac anatomy and physiology, electrophysiology, waveforms, arrhythmias, and... View Details


Compact Clinical Guide to Arrhythmia and 12-Lead EKG Interpretation
by Sandra Goldsworthy RN MSc PhD(c) CNCC(C) CMSN(C) (Author), Leslie Graham RN MN CNCC(C) CHSE (Author)

Translates difficult concepts into easy-to-master competencies

This is a user-friendly, step-by-step approach to the challenging clinical topic of Arrhythmia and 12-lead EKG interpretation in the Critical Care andAcute Care settings. Thoroughly researched and authored by nurses for nurses, the guide provides detailed and comprehensive concepts of Arrhythmia and12-lead EKG interpretation with an emphasis on the nurse's role. Written by nurses with extensive experience in mentoring novice and experienced nurses asthey transition into the Critical Care arena, the book delivers the... View Details

Best Science Podcasts 2017

We have hand picked the best science podcasts for 2017. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Simple Solutions
Sometimes, the best solutions to complex problems are simple. But simple doesn't always mean easy. This hour, TED speakers describe the innovation and hard work that goes into achieving simplicity. Guests include designer Mileha Soneji, chef Sam Kass, sleep researcher Wendy Troxel, public health advocate Myriam Sidibe, and engineer Amos Winter.
Now Playing: Science for the People

#448 Pavlov (Rebroadcast)
This week, we're learning about the life and work of a groundbreaking physiologist whose work on learning and instinct is familiar worldwide, and almost universally misunderstood. We'll spend the hour with Daniel Todes, Ph.D, Professor of History of Medicine at The Johns Hopkins University, discussing his book "Ivan Pavlov: A Russian Life in Science."