A Study on The Genesis of "f" Waves of Atrial fibrillation in Man Considered as Multiple Statistical Time Series

The fluctuations of base line of the electrocardiogram (ECG) in man with chronic atrial fibrillation (f waves) were considered as random signals. Simultaneously recorded ECGs from several points on the chest wall, in the esophagus and the right intracardiac cavities were regarded as multiple statistical time series. A spectral matrix was computed from them, and the number and location of the f wave generators and the direction of the circulating excitation wave were estimated or determined by principal component analysis of the spectral matrix, and further multiple and partial coherences between the f waves of simultaneous ECGs were computed. Then, the following conclusions were obtained: 1. The number of generators for the f waves was one and this generator was apparently located somewhere in the right atrium. Stimuli from here generated a circulating excitation wave which descended in the right atrium and ascended in the left. Further, the number of generators was one, which was clearly interpreted from the values of multiple coherences. Therefore, it was evidently demonstrated that f waves were produced by neither ectopic impulse formation nor microre-entry but by macrore-entry (circus movement) in addition to the presence of one generator (focus), as supported also by mere inspection of simultaneously recorded ECGs. 2. In reference to the results of computer simulation conducted hitherto by several authors, it was postulated that atrial fibrillation was initiated by an appropriate premature beat and the perpetuation of this arrhythmia was maintained by a circulating excitation wave, but from the present investigation and the theory recently advanced by Cranefield, one focus persistently sending out impulses at a certain frequency in one direction only could be thought necessary for the initiation and possibly for the perpetuation of atrial fibrillation.