Study of self maintaining spatial spiral waves in ventricular tissue

Aims: This study focuses on the most important cardiac malfunction cases responsible for sudden cardiac death and on detailed visualization of all formation phases of the deadly, self maintaining spiral waves (SW) that may occur in the ventricular tissue and develop ventricular fibrillation (VF). Methods: We developed a spatio-temporal computerized model of the whole heart that handles half millimeter sized compartments using 1μs time step. We employed the effect of muscle fiber direction, laminar sheets, depolarization period and other parameters. In presence of ischemia, normal parameter values were no longer maintained. In our simulation the depolarization wave (DW) conduction speed of the injured-but still functioning-tissue was decreased by up to 20 times, while the chance of spontaneous ectopic-firing (SEF) was increased by up to 1000 times. Results: Under normal conditions the development probability of the SW was under 2% using 1-hour simulated period and had a 90% correlation with ventricular stimulation speed, and 75% with minimal depolarization period of the ventricular tissue. Conclusion: Large size and low conducting speed of the injured ventricular tissue and the high probability of SEF are the main generating factors of SW.