Alternans Lowers the Scaling Exponent of Heartbeat Fluctuation Dynamics: A Detrended Fluctuation Analysis in Animal Models and Humans

The period-2 rhythm so called as ldquoAlternansrdquo is an arrhythmia exhibiting alternating amplitude or alternating interval from heartbeat to heartbeat, which was first described in 1872 by Traube. Recently, Alternans was finally recognized as the harbinger of a cardiac disease, because physicians noticed that an ischemic heart exhibits Alternans. To quantify irregularity of the heartbeat, including Alternans, we used the detrended fluctuation analysis (DFA). We revealed that in both, animal models and humans, the Alternans rhythm lowers the scaling exponent. With the scaling exponents calculation by the DFA it might be possible to find out a reliable sign for a risk for the ldquofailingrdquo heart.