Causality relation map: A novel methodology for the identification of hierarchical fibrillatory processes

Cardiac fibrillation is a complex arrhythmia whose mechanisms of onset, maintenance and interruption are not completely understood. Fibrillatory processes have usually been considered as random phenomena without any apparent coordinated pattern. However, recently developed experimental and human studies have demonstrated that a hierarchical activation may govern some fibrillatory processes. In this study a novel methodology for the identification of hierarchical activation patterns is presented. Specifically, causal relations between neighboring electrodes are used to identify predominant propagation directions. The presented methodology may be of useful to identify regions of the myocardium that may sustain a fibrillatory process and consequently are targets for arrhythmia termination.