Chaos Detection In Ventricular Wall Thickness Pulsatility

Introduction: The presence of nonlinearities in physiological interactions imposes a limitation to linear analysis in providing a full description of the underlying dynamics. In this sense, when a cardiovascular time series is considered, useful information about the involved system can be obtained through the application of chaos theory. In the present work, chaotic metrics were applied to the pulsatility of the ventricular wall thickness (VWT) in order to perform the characterization of its source process. Materials and Methods: Five mongrel dogs were operated on, where two pairs of ultrasonic microcrystals were implanted at the left ventricular walls for continuous VWT measurements. Nonlinear analysis of VWT was performed by means of phase space reconstruction, determinism evaluation and largest Lyapunov exponent assessment. Results: VWT Chaotic behavior was verified by means of determinism factor values closer to 1 and positive largest Lyapunov exponents. Conclusion: Nonlinear system characterization of ventricular wall pulsatility can be related to a chaotic process.