Heart rate variability and stroke: Strange attractors with loss of complexity

摘要

The publication of James Gleick's book 'Chaos: Making a New Science in 1987 brought the terminology of the 'butterfly effect' into popular parlance [1]. This esoteric and rather poetic concept refers to the dependence of the response of a system to initial conditions, such that the flapping of the wings of a butterfly in one location can perturb the weather pattern so as to cause a tornado at a distant location. As an illustrative' concept, it was developed by the renowned mathematician and meteorologist, Edward Lorenz [2], who showed that simple perturbations with different initial conditions can evolve into different states that are unstable and exhibit a complex and chaotic behavior. These chaotic states are bounded by paths that form attractors, where the specific path is determined by initial conditions, much like the oscillation of a pendulum.