Letter by Jalife et al Regarding Article, “Quantitative Analysis of Localized Sources Identified by Focal Impulse and Rotor Modulation Mapping in Atrial Fibrillation”

> Nothing is more irredeemably irrelevant than bad science > > —John C. Polanyi> > German-Canadian chemist > > Nobel Prize for Chemistry in 1986 In 1998, we introduced a unique phase mapping algorithm that markedly enhanced the characterization of complex spatiotemporal patterns of cardiac fibrillation.1 We used a potentiometric dye and video imaging to record the dynamics of transmembrane potentials at many sites during fibrillation.1,2 Transmembrane signal at each site exhibited strong periodic components at 8 to 15 Hz and was seen as a quasi-closed trajectory in 2-dimensional phase space that could be represented by its phase around the circuit.1 Spatial phase maps at each instant revealed drivers of fibrillation in the form of rotors displaying long-lasting topological defects or phase singularity points at a few sites. We also demonstrated that such drivers are caused by a singularity event termed wavebreak. Subsequently, the combined use of phase and dominant frequency (DF) maps of the optical movies led to the demonstration that atrial fibrillation (AF) in the isolated sheep heart was characterized by a hierarchy of DF domains where the highest domain (DFmax) corresponded to the location of the dominant rotor.3–7 More recent data suggest that rotors may underlie both paroxysmal and persistent AF in humans.8–12 Thanks to the recent introduction of mapping technology that uses a multielectrode basket catheter and is designed to identify highly localized drivers capable of maintaining AF, the field of AF ablation has begun to move away from purely anatomically based strategies. During the last several years, ablation studies using novel mapping procedures specifically designed to assess the mechanism(s) underlying potential AF sources have been reported with promising results. Such mechanistically based ablation techniques are a direct result of insights into the dynamic behavior of reentrant sources (rotors) derived …