Chaos in cardiac signals.

Chaotic dynamical systems analysis has become over the last two decades a standard tool for systems analysis in the hydrodynamics of turbulence, in mechanical systems, and in electrical signals. The label "chaotic" has summarized the lack of predictability of the weather and other complex systems. We can use "chaos" theory to enhance our understanding of cardiovascular pressures, flows, heart rates, and tracer exchanges. Explaining why we cannot predict exactly is an improvement over not understanding at all, and aids in taking the next steps toward deeper insight at the biochemical and electrophysiologic levels.