Analysis of a Modified Feedback Control Technique for Suppressing Electrical Alternans in Cardiac Tissue

Alternans is an abnormal cardiac rhythm in which action potential duration alternates from beat-to-beat. In order for an implanted pacemaker to successfully seize control of the heart rhythm, its electrical stimuli have to be carefully timed relative to the firing of the heart’s specialized pacemaker cells. In this manuscript, we use mathematical techniques to analyze a novel feedback control algorithm for suppressing alternans. We model the cardiac rhythm and the effect of the controller using a system of two nonlinear difference equations. Our analysis reveals that it is often advantageous not to allow the pacemaker to intervene in every beat when attempting to control alternans.