Reentrant mechanisms triggered by ectopic activity in a three-dimensional realistic model of human atrium. a computer simulation study

Atrial fibrillation (AF) is the most common tachiarrhythmia. The pulmonary veins (PVs) have the predominant source of ectopic activity involved in the initiation of AF. Atrial remodelling, due to rapid and irregular activation during AF, leaves the tissue vulnerable to reentries. In this work the effects of electrical remodelling were incorporated in a 3D anisotropic model of human atrium. An ectopic focus was applied near to PVs. Electrograms were computed in simulated-electrodes in back wall of left atrial. The ectopic focus induced a figure-of-eight reentry that degenerated to mother rotor, after collisions and wave breaks were observed. Electrograms were more irregular during figure-of-eight reentry and collisions than during rotor activity. Spectral analysis shows multiple frequency peaks, as a consequence of changes of reentrant patterns. Dominant frequency was similar in all measuring points.