(36d) Mechano-Electric Stabilization of Cardiac Alternans

Alternation of normal action potential morphology in the myocardium is a condition with a beat-to-beat oscillation in the length of the electric wave which is linked through the electromechanical coupling to the cardiac muscle contraction, and is believed to be the first manifestation of the onset of the life threatening ventricular arrhythmias and sudden cardiac death. Alternation of action potential is described by the small amplitude of alternans parabolic PDEs. Spatially uniform unstable steady state of the alternans amplitude is stabilized by optimal control methods through boundary and spatially distributed actuation. Mixed boundary and spatially distributed actuation is realized by the finite dimensional linear quadratic regulator (LQR) in the full state feedback control structure, and in a compensator design with the Luenberger observer, and it achieves exponential stabilization in a finite size tissue cable length. An important issue of ability to realize such control algorithm is analyzed on the basis of the structure of the amplitude of alternans equation and control methodology applied. This combined mechano-electric interaction with cardiac tissue paves new avenue in the research of applicable anti-arrhythmic cardiac devices.