Case Study: Studies of Cardiac Arrhythmia at Duke University

At Duke University, equations drive the mathematical and computer models that biomedical engineering students and researchers use to study heartbeats and causes of cardiac arrhythmias, or irregular heartbeats. Advanced Visual Systems' AVS software brings these students and researchers a step closer to understanding heart dysfunction by allowing them to illustrate the equations using powerful 3D representations.

Reconstructed pig heart from MRI images, showing simulated extracellular potential distribution arising from midwall stimulation in a 3D bidomain model of tissue (black marks indicate local fiber direction). Below the block are simulated cardiac action potentials generated from the Luo-Rudy membrane model. (Click to enlarge)

Instead of writing individual equations, testing each hypothesis and illustrating results with cumbersome numerical charts and one-dimensional graphs, students can now manipulate equation variables and combine more data into a single visualization. AVS makes it easy for students -- from first-semester freshmen to advanced graduate students -- to understand their data and represent it in a way others can learn from it as well, such as illustrating model data points that represent the heart's electrical activity using a range of colors.

"With AVS, students have a way to look at data from different perspectives and get an accurate picture of it," said Dr. Craig Henriquez, assistant professor of biomedical engineering at Duke University. "Students can learn the fundamentals of AVS in less than a week and do remarkable things with their own data. Instead of spending their time writing visualization code, they can better spend their time analyzing data and drawing research conclusions."

Researchers have studied cardiac tissues and electrical activity to understand cardiac arrhythmias for many years, but these experiments are limited in scope because electrodes cannot be placed on a living heart. Mathematical and computer models provide a means of using information from experimentation on single cells and bits of tissue to form a more precise understanding of the organized contraction of the whole heart.AVS allows integration of laboratory and simulated modeling data to capture not only what is happening on the outside of the heart, but also everything that is happening between the walls for a comprehensive view of activity.

"The eventual goal is to model heart conduction of a given patient to visualize the spread of electrical activation across the muscle. This will help us determine the source of, and the best treatment for, arrhythmia," explained Henriquez. "AVS is helping students develop computer models to understand how the heart works and make advances in cardiac research. Using AVS and AVS/Express in the future, these same models may be integrated directly into medical devices to help clinicians diagnose and treat life-threatening arrhythmias, providing better quality care," concluded Henriquez.