14. Ventricular Fibrillation & Out-of-Hospital Cardiac Arrest: 14.1 The Chaos Theory and Electrophysiology in Ventricular Fibrillation

Chaos theory is particularly attractive to those, who are studying ventricular fibrillation, because of the way it describes complex phenomena.

The study group consisted of 15 rabbits, which were anesthetized (midazolam dose 0,75 mg/kg/h) and then ventricular fibrillation (VF) was induced: in 5 cases by pacing transesophageal electrode (12 V, 50 Hz); in 5 by epinephrine (1mg/kg) and in 5 by calcium intravenously (0,001/kg). After 5 minutes of cardiac arrest defibrillation shock was delivered. If defibrillation was unsuccessful the cardiopulmonary resuscitation was started. ECG data were analyzed using a numerical technique, based on discrete signal wavelet packet analysis of determining chaotic states of a signal.

Transition from a non-chaotic state to a chaotic state manifested itself in the magnitude and distribution of system response wavelet expansion coefficients. No features connected with chaotic processes were observed during sinus rhythm and ventricular fibrillation. Features connected with chaotic processes were associated only with ventricular tachycardia.

1. The standard EKG registration does not allow the analysis of developed chaotic process in myocardium during ventricular fibrillation. 2. Chaotic characteristic could be found in ventricular tachycardia.