Spatiotemporal Control of Reentrant Tachycardias

Friday, March 13, 1998 - 11:00am - 12:00pm
Keller 3-180
Alain Karma (Northeastern University)
Reentrant tachycardias are abnormally fast cardiac rhythms produced by the circulation of electrical activity around some anatomical obstacle in the heart, or by spiral wave rotation around a phase singularity in homogeneous tissue. These arrhythmia are especially dangerous because they can become unstable and decay into fibrillation, a wave turbulent state that destroys the main pumping function of the heart if present in the ventricle. I will discuss the results of a modeling study aimed at controlling a known oscillatory instability of reentrant excitations in both one-dimensional rings and thin two-dimensional sheets of tissue. The good news is that control can be achieved, and the decay into turbulence prevented, with a relatively small number of spatially distributed pacing electrodes and a relatively simple control scheme. The bad news, however, is that ventricular fibrillation can also be produced by a distinct three-dimensional instability of scroll wave filaments that would require a completely different control strategy, yet to be developed.