Short-term forecasting of life-threatening cardiac arrhythmias based on symbolic dynamics and finite-time growth rates

Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 2000 Jan;61(1):733-9. doi: 10.1103/physreve.61.733.

Abstract

Ventricular tachycardia or fibrillation (VT-VF) as fatal cardiac arrhythmias are the main factors triggering sudden cardiac death. The objective of this study is to find early signs of sustained VT-VF in patients with an implanted cardioverter-defibrillator (ICD). These devices are able to safeguard patients by returning their hearts to a normal rhythm via strong defibrillatory shocks; additionally, they store the 1000 beat-to-beat intervals immediately before the onset of a life-threatening arrhythmia. We study these 1000 beat-to-beat intervals of 17 chronic heart failure ICD patients before the onset of a life-threatening arrhythmia and at a control time, i.e., without a VT-VF event. To characterize these rather short data sets, we calculate heart rate variability parameters from the time and frequency domain, from symbolic dynamics as well as the finite-time growth rates. We find that neither the time nor the frequency domain parameters show significant differences between the VT-VF and the control time series. However, two parameters from symbolic dynamics as well as the finite-time growth rates discriminate significantly both groups. These findings could be of importance in algorithms for next generation ICD's to improve the diagnostics and therapy of VT-VF.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms
  • Arrhythmias, Cardiac / diagnosis*
  • Arrhythmias, Cardiac / physiopathology
  • Arrhythmias, Cardiac / therapy
  • Biophysical Phenomena
  • Biophysics
  • Defibrillators, Implantable
  • Heart Failure / physiopathology
  • Heart Failure / therapy
  • Heart Rate
  • Humans
  • Models, Cardiovascular
  • Nonlinear Dynamics
  • Tachycardia, Ventricular / diagnosis
  • Tachycardia, Ventricular / physiopathology
  • Tachycardia, Ventricular / therapy
  • Ventricular Fibrillation / diagnosis
  • Ventricular Fibrillation / physiopathology
  • Ventricular Fibrillation / therapy