the controllability of cardiac rhythm in elderly

Introduction: recent reports have shown that rare fluctuations in cardiac cycles are ‘forgotten’ quickly in healthy individuals and it is possible to quantify the “memory length” of a physiological time-series using an inverse statistical approach. methods: in the present study, we assessed the effect of aging on memory length in cardiac rhythm. results: there was a longer memory length in cardiac time-series of elderly subjects in comparison with younger adults for both decelerating and accelerating rare fluctuations in cardiac rhythm. conclusion: the increased memory length of the cardiac time-series in elderly subjects may indicate reduced controllability of cardiovascular regulatory system.