You re causing ectopy...oh. He s dead. It s alright, keep trying. Those were the words of a fellow biomedical engineer this past May at the annual Heart Rhythm meeting. I was using a cath lab simulator, trying to insert an ICD lead into a simulated heart. The technician was doing his best to help me. He recommended various wires and other devices, told me where to put things, when to twist, when to feed it in further. To me, the image on the fluoroscope looked like a wire wiggling rhythmically in empty space. Eventually, I had to leave and gave up, though not without some taunting from the technician.

The reason for my difficulty is that I don t normally do that type of work. I m a Ph.D. student in Tulane University s Computational Cardiac Electrophysiology Lab. As such, when I was approached about writing this article, I was concerned that I would be addressing the wrong crowd. However, I welcome this opportunity to show you what we do in a computational lab. First, I ll tell you who we are and why we re here. Next, I ll outline our major projects, and how we accomplish them. Finally, I ll try to tie our experiments in with your daily work.

Dr. Natalia Trayanova, who has had over 80 publications since 1982, directs our lab. Our research analyst, Robert Blake, maintains and continually improves our software. Viatcheslav Gurev, our newest postdoctoral researcher, has been working on simulating electro-mechanical feedback. The bulk of the research work in the lab is done by a complement of eight students. Six are Ph.D. students, including David Bourn, Molly Maleckar, Samuel Kuo, Weihui Li, Xiao Jie, and myself. The other two, Jason Constantino and Hermenegild Arevalo, are master s students.

Why use a computational model to study the heart? There are fundamental problems with the use of live models for cardiac electrophysiology research. Studying human subjects is typically encumbered by a lot of red tape, and the studies that can be done are limited. The use of large grids of plunge electrodes or optical mapping in humans is next to impossible. These techniques are usable in animal models. However, even the best experiments using them are limited in critical ways. Grids of plunge electrodes have coarse resolutions. The plunge electrodes can also damage the tissue and thereby cause recording artifacts. Even when the resolution is sufficient, large shocks can saturate recording equipment and prevent data collection during the critical time following said shocks. The most popular alternative, optical mapping, is limited to the surface of the tissue sample. Even with the use of mathematical tricks, it cannot reveal the pattern of conduction more than three or four cells deep. Despite these shortcomings, there is no question at this time that human and animal studies are both useful and necessary. A real heart is the system that we wish to understand. However, computational modeling of that system can contribute greatly to our understanding of harmful arrhythmias.