Spatio-temporal correlation of paced cardiac tissue

Complex spatiotemporal alternans patterns of action potential duration have been recently observed in large mammalian hearts. Multiple routes between the occurrence of high-order rhythms (discordant alternans) and their transition to chaos (ventricular fibrillation) have also been reported. In this work we extend the analysis of voltage optical mapped signals from right canine ventricles during rhythmic and arrhythmic regimes. We evaluate the correlation length between pairs of points of large spatial domains to extract the typical length scale of the system in different regimes. Critical scale length transitions are discussed with respect to regular pacing frequencies and onset of fibrillation.