Phase defects as a new paradigm to understand and control electrical patterns in the heart

The human heart is a prime example of self-organization, as its mechanical contraction is steered by non-linear waves of electrical depolarization that the cardiac muscle cells pass to each other. Abnormal electrical patterns are causing cardiac arrhythmias, which are still a major cause of death worldwide. Many arrhythmias are organized by rotating vortices called rotors, whose dynamics are incompletely understood. In this work, it is shown that the classical hypothesis of a phase singularity at the center of these vortices is incomplete, and that instead a phase defect line occurs, similar to domain walls in physics and branch cuts in complex analysis. We develop a novel theoretical framework for cardiac excitation patterns, guided by experimental observations and using techniques from mathematical physics. Moreover, we discover the building blocks related to phase defects, and analyze via diagrams, which consist of bullets (events of the particles) and arrows (continuation of particles in space and time). The constructed diagrams are similar to the Feynman diagram, which is an essential tool to understand the behavior of subatomic particles in theoretical physics.